Pyrrolizidine alkaloids(PAs)are natural toxins generated as secondarymetabolites in plants,predominantly consisting of unsaturated PAs with diverse toxicities,such as hepatotoxicity.Echimidine,a prominent PA,is believ...Pyrrolizidine alkaloids(PAs)are natural toxins generated as secondarymetabolites in plants,predominantly consisting of unsaturated PAs with diverse toxicities,such as hepatotoxicity.Echimidine,a prominent PA,is believed to exert various toxicological effects,including survival inhibition and induction of apoptosis of hepatocytes.However,the effects of echimidine on development remain unclear.We selected three concentrations of 0.02,0.2,and 2 mg/L to investigate the developmental toxicity of echimidine on zebrafish embryos.After a 7-day exposure,we observed hyperactivity and anxiety-like behavior in zebrafish larvae.Furthermore,we found that echimidine exposure significantly promoted embryonic motor neurodevelopment in geneticallymodified zebrafish.Next,we detected that echimidine exposure significantly increased the content of the excitatory neurotransmitter acetylcholine(ACh),accompanied by a significant decrease in acetylcholinesterase(AChE)activity.Conversely,echimidine led to a significant reduction in the content of the sedative neurotransmitterγ-aminobutyric acid(GABA),accompanied by abnormal gene expression of enzymes related to GABA synthesis.Moreover,we elucidated the strong direct binding of echimidine to zebrafish and human AChE protein through molecular docking.In summary,our study found that echimidine induced ACh accumulation possibly by inhibiting AChE activity,leading to motor neurodevelopmental abnormalities and hyperactivity in zebrafish larvae.This work provides important scientific knowledge on the effects and mechanisms of PAs on neural development,which is helpful for controlling the risk of PAs in food and protecting public health.展开更多
Metformin,a first-line drug for type-2 diabetes,has been shown to improve locomotor recovery after spinal cord injury.However,there are studies reporting no beneficial effect.Recently,we found that high dose of metfor...Metformin,a first-line drug for type-2 diabetes,has been shown to improve locomotor recovery after spinal cord injury.However,there are studies reporting no beneficial effect.Recently,we found that high dose of metformin(200 mg/kg,intraperitoneal)and acute phase administration(immediately after injury)led to increased mortality and limited locomotor function recovery.Consequently,we used a lower dose(100 mg/kg,i.p.)metformin in mice,and compared the effect of immediate administration after spinal cord injury(acute phase)with that of administration at 3 days post-injury(subacute phase).Our data showed that metformin treatment starting at the subacute phase significantly improved mouse locomotor function evaluated by Basso Mouse Scale(BMS)scoring.Immunohistochemical studies also revealed significant inhibitions of microglia/macrophage activation and astrogliosis at the lesion site.Furthermore,metformin treatment at the subacute phase reduced neutrophil infiltration.These changes were in parallel with the increased survival rate of spinal neurons in animals treated with metformin.These findings suggest that low-dose metformin treatment for subacute spinal cord injury can effectively improve the functional recovery possibly through anti-inflammation and neuroprotection.This study was approved by the Institute Animal Care and Use Committee at the University of Texas Medical Branch(approval No.1008041C)in 2010.展开更多
The spinal cord has the ability to regenerate but the microenvironment generated after trauma reduces that capacity. An increase in Src family kinase （SFK） activity has been implicated in neuropathological condition...The spinal cord has the ability to regenerate but the microenvironment generated after trauma reduces that capacity. An increase in Src family kinase （SFK） activity has been implicated in neuropathological conditions associated with central nervous system trauma. Therefore, we hypothesized that a decrease in SFK activation by a long-term treatment with 4-amino-5-（4- chlorophenyl）-7-（t-butyl）pyrazolo[3,4-d]pyramidine （PP2）, a selective SFK inhibitor, after spinal cord contusion with the New York University （NYU） impactor device would generate a permissive environment that improves axonal sprouting and/or behavioral activity. Results demonstrated that long-term blockade of SFK activation with PP2 increases locomotor activity at 7, 14, 21 and 28 days post-iniury in the Basso, Beattie, and Bresnahan open field test, round and square beam crossing tests. In addition, an increase in white matter spared tissue and serotonin fiber density was observed in animals treated with PP2. However, blockade of SFK activity did not change the astrocytic response or infiltration of cells from the immune system at 28 days post-injury. Moreover, a reduced SFK activity with PP2 diminished Ephexin （a guanine nudeotide exchange factor） phosphorylation in the acute phase （4 days post-injury） after trauma. Together, these findings suggest a potential role of SFK in the regulation of spared tissue and/or axonal outgrowth that may result in functional locomotor recovery during the pathophysiology generated after spinal cord injury. Our study also points out that ephexinl phosphorylation （activation） by SFK action may be involved in the repulsive microenvironment generated after spinal cord injury.展开更多
Tail autotomy is a defense mechanism used by many lizards to evade predators, but it entails costs. We used the oriental leaf-toed gecko Hemidactylus bowringii as a model animal to evaluate locomotor costs of tail aut...Tail autotomy is a defense mechanism used by many lizards to evade predators, but it entails costs. We used the oriental leaf-toed gecko Hemidactylus bowringii as a model animal to evaluate locomotor costs of tail autotomy. We removed the tail about 5 mm from the tail base from each of the experimental geckos(adult males) initially having intact tails. Tailless experimental geckos and tailed control geckos were measured for overall speed and sprint speed in both vertical and horizontal directions. Overall speed and sprint speed did not differ between tailless and tailed geckos. The influence of locomotor direction on both overall speed and sprint speed was significant, with horizontal speed being greater than vertical speed. The interaction between tail condition and locomotor direction was not significant in overall speed, but was significant in sprint speed. Tailless geckos had faster vertical sprint speed than the tailed individuals. Of the 130 field-caught adults, 59 had previously lost their tails, with most(about 61%) of them shedding their tails near the tail base. Neither the proportion of geckos with tail autotomy nor the frequency distribution of locations of the tail break differed between the sexes. Our data show that tail loss of H. bowringii occurs frequently in nature. However, tail loss does not incur locomotor costs in this gecko.展开更多
Objective:To evaluate the neuroprotective effects of the organic components of scallop shells(scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibe...Objective:To evaluate the neuroprotective effects of the organic components of scallop shells(scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo(a,d) cyclohepten-5,10-imine(MK801).Methods:Effect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test,the Morris water maze test,and the open field test.Results:Scallop shell extract significantly reduced scopolamine-induced short-term memory impairment and partially reduced scopolamine-induced spatial memory impairment in the Morris water maze test.Scallop shell extract suppressed scopolamine-induced elevation of acetylcholine esterase activity in the cerebral cortex.Treatment with scallop shell extract reversed the increase in locomotor activity induced by scopolamine.Scallop shell extract also suppressed the increase in locomotor activity induced by MK801.Conclusions:Our results provide initial evidence that scallop shell extract reduces scopolamine-induced memory impairment and suppresses MK-801-induced hyperlocomotion.展开更多
OBJECTIVE： To investigate the effects of myelotomy on locomotor recovery in rats subjected to spinal cord injury. DATA SOURCES： Electronic databases including Pub Med, Science Citation Index, Cochrane Library, China...OBJECTIVE： To investigate the effects of myelotomy on locomotor recovery in rats subjected to spinal cord injury. DATA SOURCES： Electronic databases including Pub Med, Science Citation Index, Cochrane Library, China National Knowledge Infrastructure, Chinese Journals Full-text Database, China Biology Medicine disc, and Wanfang Database were searched to retrieve related studies published before September 2017. The Me SH terms（the Medical Subject Headings） such as ＂myelotomy＂, ＂spinal cord injuries＂, ＂rats＂, ＂randomized controlled trial＂ and all related entry terms were searched. DATA SELECTION： Randomized controlled trials using myelotomy for the treatment of acute spinal cord injury in rats were included. Basso, Beattie, and Bresnahan scores were adopted as the evaluation method. Rev Man Software（version 5.3） was used for data processing. The χ^2 and I^2 tests were used to assess heterogeneity. Using a random-effects model, a subgroup analysis was conducted to analyze the source of the heterogeneity. OUTCOME MEASURES： Basso, Beattie, and Bresnahan scores were observed 1–6 weeks after spinal cord injury.RESULTS： Six animal trials were included, using a total of 143 lab rats. The included trials were divided into two subgroups by injury degrees（moderate or severe）. The pooled results showed that, 1–6 weeks after spinal cord injury, the overall Basso, Beattie, and Bresnahan score was significantly higher in the myelotomy group than in the contusion group（weighted mean difference（WMD） = 0.60; 95% confidence interval（CI）： 0.23–0.97; P = 0.001; WMD = 2.10; 95% CI： 1.56–2.64; P 〈 0.001; WMD = 2.65; 95% CI： 1.73–3.57; P 〈 0.001; WMD = 1.66; 95% CI： 0.80–2.52; P 〈 0.001; WMD = 2.09; 95% CI： 0.92–3.26, P 〈 0.001; WMD = 2.25; 95% CI： 1.06–3.44, P 〈 0.001）. The overall heterogeneity was high（I^2 = 85%; I^2 = 95%; I^2 = 94%; I^2 = 88%; I^2 = 91%; I^2 = 89%）. The results in the moderate injury subgroup showed that Basso, Beattie, and Bresnahan scores were significantly higher in the myelotomy group than in the contusion group（WMD = 0.91, 95% CI： 0.52–1.3, P 〈 0.001; WMD = 2.10; 95% CI： 1.56–2.64, P 〈 0.001; WMD = 2.65; 95% CI： 1.73–3.57, P 〈 0.001; WMD = 2.50, 95% CI： 1.72–3.28, P 〈 0.001; WMD = 3.29, 95% CI： 2.21–4.38, P 〈 0.001; WMD = 3.27; 95% CI： 2.31–4.23, P 〈 0.001）. The relevant heterogeneity was low. However, there were no significant differences in Basso, Beattie, and Bresnahan scores between the myelotomy and contusion groups in the severe injury subgroup at 2 and 3 weeks after the injury（P = 0.75; P = 0.92）. CONCLUSION： To date, this is the first attempt to summarize the potential effect of myelotomy on locomotor recovery in rats with spinal cord injury. Our findings conclude that myelotomy promotes locomotor recovery in rats with spinal cord injury, especially in those with moderate injury.展开更多
The significant influence of thermal acclimation on physiological and behavioral performance has been documented in many ectothermic animals, but such studies are still limited in turtle species. We acclimated hatchli...The significant influence of thermal acclimation on physiological and behavioral performance has been documented in many ectothermic animals, but such studies are still limited in turtle species. We acclimated hatchling soft-shelled turtles Pelodiscus sinensis under three thermal conditions （10, 20 and 30~C） for 4 weeks, and then measured selected body temperature （Tsel）, critical thermal minimum （CTMin） and maximum （CTM^x）, and locomotor performance at different body temperatures. Thermal acclimation significantly affected thermal preference and resistance of P sinensis hatchlings. Hatchling turtles accli- mated to 10~C selected relatively lower body temperatures and were less resistant to high temperatures than those acclimated to 20~C and 30~C. The turtles＇ resistance to low temperatures increased with a decreasing acclimation temperature. The thermal re- sistance range （i.e. the difference between CTM^x and CTMin, TRR） was widest in turtles acclimated to 20~C, and narrowest in those acclimated to 10~C. The locomotor performance of turtles was affected by both body temperature and acclimation tem- perature. Hatchling turtles acclimated to relatively higher temperatures swam faster than did those acclimated to lower temperatures. Accordingly, hatchling turtles acclimated to a particular temperature may not enhance the performance at that temperature. Instead, hatchlings acclimated to relatively warm temperatures have a better performance, supporting the ＂hotter is better＂ hypothesis.展开更多
Oscillating field stimulation(OFS)is a potential method for treating spinal cord injury.Although it has been used in spinal cord injury(SCI)therapy in basic and clinical studies,its underlying mechanism and the correl...Oscillating field stimulation(OFS)is a potential method for treating spinal cord injury.Although it has been used in spinal cord injury(SCI)therapy in basic and clinical studies,its underlying mechanism and the correlation between its duration and nerve injury repair remain poorly understood.In this study,we established rat models of spinal cord contusion at T10 and then administered 12 weeks of OFS.The results revealed that effectively promotes the recovery of motor function required continuous OFS for more than 6 weeks.The underlying mechanism may be related to the effects of OFS on promoting axon regeneration,inhibiting astrocyte proliferation,and improving the linear arrangement of astrocytes.This study was approved by the Animal Experiments and Experimental Animal Welfare Committee of Capital Medical University(supplemental approval No.AEEI-2021-204)on July 26,2021.展开更多
We studied the locomotor behaviour of white-headed langurs Trachypithecus leucocephalus and Francois＇ langurs T.francoisi to test two hypotheses： （1） these monkeys have evolved locomotor ability to support their a...We studied the locomotor behaviour of white-headed langurs Trachypithecus leucocephalus and Francois＇ langurs T.francoisi to test two hypotheses： （1） these monkeys have evolved locomotor ability to support their activities on limestone hills, and （2） Francois＇ langurs have evolved more diverse locomotor skills than white-headed langurs. Data were collected from 1996 - 1998 and in 2005 in Fusui Nature Reserve, Guangxi, and showed that the two species had similar locomotor types, but Francois＇ langurs had more locomotor modes （26） than white-headed langurs （12）. Quadrupedal walking and leaping were two major types, and white-headed langurs were more arboreal than Francois＇ langurs. We suggest that, while keeping their ancestral locomotor types, the two species have evolved new types allowing them to live on limestone cliffs. Compared to white-headed langurs, Francois＇ langurs have more diverse locomotor modes that probably have allowed them to live in more habitat types. As an evolutionary outcome, Francois＇ langurs have a larger distribution range .展开更多
Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the...Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the capture of flexible, small animals with complex locomotor behaviors, the markers interfere with each other easily, and the motion forms(bending, twisting) of the moving parts are obviously different;thus, it is a great challenge to realize accurate quantitative characterization of complex locomotor behaviors. The correlation between the marker properties, including the size and space length, and the precision of the system are revealed in this paper, and the effects of diverse marker shapes on the capturing accuracy of the captured objects in different motion forms were tested. Results showed that the precision of system is significantly improved when the ratio of the space length to the diameter of the markers is larger than four;for the capture of the spatial twisting motion of the flexible object, the hexagon markers had the lowest spatial lost-marker rate relative to the circle, triangle, and square. Customized markers were used to capture the locomotor behavior of the gecko-inspired robot(rigid connection) and the gecko(flexible connection). The results showed that this marking technology can achieve high accuracy of motion capture for geckos(the average deviation was approximately 0.32 mm, and the average deviation’s variation rate was approximately 0.96%). In this paper, the marking technology for the motion capture of flexible, small animals with complex motion is proposed;it can effectively improve the system precision as well as the capture accuracy, and realize the quantitative characterization of the complex motion of flexible, small objects. It provides a reliable technical means to deeply study the evolution of the motion function of small animals and advance systematic research of motion-capture technology.展开更多
This study sought to elucidate the changes of nuclear factor kappa B （NF-KB） expression and locomotor function of hind limb after subdural injection of BMS-345541 was applied in rats with acute spinal cord injury. T...This study sought to elucidate the changes of nuclear factor kappa B （NF-KB） expression and locomotor function of hind limb after subdural injection of BMS-345541 was applied in rats with acute spinal cord injury. The results indicated that BMS-345541 treatment reduced the expression of NF-kB at 24 hours after injury, compared with normal saline-treated rats. This treatment also led to a significant improvement in locomotor functional recovery at 14 days after injury. Overall, the findings demonstrated that BMS-345541 significantly ameliorated spinal cord injury-induced hind limb dysfunction by inhibiting the expression of NF-kB after spinal cord injury.展开更多
Recovery of locomotor behavior following spinal cord injury can occur spontaneously in some vertebrates, such as fish, urodele amphibians, and certain reptiles. This review provides an overview of the current status o...Recovery of locomotor behavior following spinal cord injury can occur spontaneously in some vertebrates, such as fish, urodele amphibians, and certain reptiles. This review provides an overview of the current status of our knowledge on the anatomical and electrophysiological changes occurring within the spinal cord that lead to, or are associated with the [e-expression of locomotion in spinally-transected salamanders. A better understanding of these processes will help to devise strategies for restoring locomotor function in mammals, including humans.展开更多
Chronic long-term exposure to cuprizone causes severe brain demyelination in mice,which leads to changes in locomotion,working memory and anxiety.These findings suggest the importance of intact myelin for these behavi...Chronic long-term exposure to cuprizone causes severe brain demyelination in mice,which leads to changes in locomotion,working memory and anxiety.These findings suggest the importance of intact myelin for these behaviors.This study aimed to investigate the possible behavioral changes in mice with mild oligodendrocyte/myelin damage that parallels the white matter changes seen in the brains of patients with psychiatric disporders.We used the cuprizonetreated mouse model to test both tissue changes and behavioral functions（locomotor activity,anxiety status,and spatial working memory）.The results showed that mice given cuprizone in their diet for 7 days had no significant myelin breakdown as evaluated by immunohistochemical staining for myelin basic protein,while the number of mature oligodendrocytes was reduced.The number and length of Caspr protein clusters,a structural marker of the node of Ranvier,did not change.The locomotor activity of the cuprizonetreated mice increased whereas their anxiety levels were lower than in normal controls;spatial working memory,however,did not change.These results,for the first time,link emotion-related behavior with mild white matter damage in cuprizone-treated mice.展开更多
Morphine can modulate the processes underlying memory in vertebrates. However, studies have shown various modulations by morphine： positive, negative and even neutral. The honeybee is a potential platform for evaluat...Morphine can modulate the processes underlying memory in vertebrates. However, studies have shown various modulations by morphine： positive, negative and even neutral. The honeybee is a potential platform for evaluating the effects of drugs, especially addictive drugs, on the nervous system. However, the involvement of morphine in learning and memory in insects or other invertebrates is poorly understood. The current work evaluated whether morphine affects memory acquisition, consolidation and retrieval in honeybees, using the proboscis extension response （PER） paradigm. We demonstrated that morphine treatment （5 pg/bee） before training decreased the percentage of correct PERs and the response latency related to aversive rather than rewarding odors when tested after 1 or 24 h. Morphine treatment after training also caused a decrease in this latency when tested after 24 h. Meanwhile, morphine treatment reduced the ambulation distance when tested after 30 min. Our findings suggest that morphine impairs the acquisition of shortand long-term associative memory and slightly disrupts the consolidation of long-term memory in honeybees. These negative effects cannot be explained by reduced locomotion but by impaired memory associated with aversion.展开更多
Amyotrophic lateral sclerosis is a motoneuron degenerative disease that is challenging to diagnose and presents with considerable variability in survival.Early identification and enhanced understanding of symptomatic ...Amyotrophic lateral sclerosis is a motoneuron degenerative disease that is challenging to diagnose and presents with considerable variability in survival.Early identification and enhanced understanding of symptomatic patterns could aid in diagnosis and provide an avenue for monitoring disease progression.Use of the m SOD1 G93 A mouse model provides control of the confounding environmental factors and genetic heterogeneity seen in amyotrophic lateral sclerosis patients,while investigating underlying disease-induced changes.In the present study,we performed a longitudinal behavioral assessment paradigm and identified an early hindlimb symptom,resembling the common gait abnormality foot drop,along with an accompanying forelimb compensatory mechanism in the m SOD1 G93 A mouse.Following these initial changes,m SOD1 mice displayed a temporary hindlimb compensatory mechanism resembling an exaggerated steppage gait.As the disease progressed,these compensatory mechanisms were not sufficient to sustain fundamental locomotor parameters and more severe deficits appeared.We next applied these initial findings to investigate the inherent variability in B6 SJL m SOD1 G93 A survival.We identified four behavioral variables that,when combined in a cluster analysis,identified two subpopulations with different disease progression rates：a fast progression group and a slow progression group.This behavioral assessment paradigm,with its analytical approaches,provides a method for monitoring disease progression and detecting m SOD1 subgroups with different disease severities.This affords researchers an opportunity to search for genetic modifiers or other factors that likely enhance or slow disease progression.Such factors are possible therapeutic targets with the potential to slow disease progression and provide insight into the underlying pathology and disease mechanisms.展开更多
The negative-geotaxis climbing assay is used to efficiently study aging and neurodegeneration in Drosophila.To make it suitable for large-scale study,a method called the rapid iterative negative geotaxis（RING） assay...The negative-geotaxis climbing assay is used to efficiently study aging and neurodegeneration in Drosophila.To make it suitable for large-scale study,a method called the rapid iterative negative geotaxis（RING） assay has been established by simultaneously photographing the climbing of multiple groups of flies when they are manually tapped down in test tubes.Here,we automated the assay by using a well-controlled electric motor to drive the tapping,and a homemade program to analyze the climbing height of flies.Using the automated RING（aRING） assay,we found that the climbing ability of a strain of wild-type flies,males in particular,declined rapidly before day 21 after eclosion,but slowly from day 21 to 35.We also found that the expression of arctic mutant Aβ_（42） accelerated the age-dependent decline in the climbing ability of flies.Moreover,using aRING,we examined the effect of third chromosome deficiencies on the accelerated locomotor decline in Aβ_（42）-expressing flies,and isolated 7 suppressors and15 enhancers.展开更多
The rodent running-wheel recording apparatus is a reliable approach for studying cir-cadian rhythm.This study demonstrated how to construct a simple and intelligent running-wheel recording system.The running wheel was...The rodent running-wheel recording apparatus is a reliable approach for studying cir-cadian rhythm.This study demonstrated how to construct a simple and intelligent running-wheel recording system.The running wheel was attached to the cage's base,whereas the Hall sensor was attached to the cage's cover.Then,the RJ25 adaptor relayed the running signal to the main control board.Finally,the main control board was connected to the USB port of the computer with the USB connection.Data were collected using the online-accessible,self-created software Magturning.Through Magturning,generated data were saved and exported in real time.Afterward,the device was validated by collecting data on the locomotor activities of mice under dif-ferent light conditions.In conclusion,this new device can record circadian activity of rodents.Our device is appropriate for interdisciplinary investigations related to biological clock research.展开更多
Previous social experience may affect subsequent behavior. It was shown by other authors that Drosophila melanogaster males kept individually are more aggressive and sexually active than males kept in a group. In the ...Previous social experience may affect subsequent behavior. It was shown by other authors that Drosophila melanogaster males kept individually are more aggressive and sexually active than males kept in a group. In the present study, we tested the locomotor activity of individual males and females previously reared either individually, or in a group. We found that keeping 20 young males for three days together led to a strong long-term (up to 5 days) reduction in their further locomotor activity as individuals. Rearing of young males in groups of other sizes (2, 5, 10, and 30) produced a smaller or no after-effect. At the same time, we have not found any difference in subsequent behavior of individual females previously kept either individually, or in a group. We suppose that in a group, flies learned to suppress their locomotor activity to prevent unpleasant contacts with other animals (operant learning). It seems that in males this learning is more efficient because of the higher level of aggression producing the stronger negative reinforcement.展开更多
There are no reports on the effect of amphetamine on female WKY circadian activity pattern. The objective of this study is to investigate whether repeated daily exposure to the psychostimulant amphetamine alters the l...There are no reports on the effect of amphetamine on female WKY circadian activity pattern. The objective of this study is to investigate whether repeated daily exposure to the psychostimulant amphetamine alters the locomotor circadian rhythm activity patterns of female adult Wistar-Kyoto (WKY) rats. Twenty-four rats were divided into two groups, control (N = 12) and experimental (N = 12), and kept in a 12:12 h light/dark cycle in an open field cage. After 5 to 7 days of acclimation, 11 days of consecutive non-stop recordings began. On experimental day 1, all groups were given an injection of saline. On experimental days 2 to 7, the experimental group was injected with 0.6 mg/kg amphetamine and the control group with saline followed by a washout phase from experimental day 8 to 10, and amphetamine re-challenge or saline on experimental day 11 similar to experimental day 2. Locomotor movements were determined using a computerized animal activity monitoring system, and cosine statistical analysis was used to fit a24-hour curve to the activity pattern. The horizontal activity (HA), total distance (TD), number of stereotypy (NOS), and stereotypical movements (SM) were analyzed for alterations in the circadian rhythm activity patterns. The data demonstrated that chronic amphetamine administration alters the mesor parameter of the circadian rhythm activity patterns, indicating that chronic amphetamine treatment exerts long term effects on these rats.展开更多
Human activities involving noise emission can affect wild animals.European mink was exposed to road noise and human voice playbacks to analyze how sound intensity level and duration of both noises altered the time tha...Human activities involving noise emission can affect wild animals.European mink was exposed to road noise and human voice playbacks to analyze how sound intensity level and duration of both noises altered the time that individuals were active and if their fecal cortisol metabolite(FCM)levels varied.A Hierarchical Analysis Cluster was performed to establish 2 mink groups with respect to both noise source type:short duration/low intensity(SL)and long duration/high intensity(LH).We performed general linear mixed models to evaluate the variation in locomotor activity duration(s)and FCM(nanogram per gram)levels,respectively.The results showed both road noise and human voices decreased locomotor activity duration in SL more sharply compared with LH,and human voices were the triggers that induced the most pronounced response to both exposure conditions.FCM(ng/g)levels increased in SL compared with LH during road noise while the opposite happened during human voices.Differences based on sex and age of individuals were observed.In conclusion,noise characteristics given by the sound type determined the variations in locomotor activity duration while noise exposure level determined the variations in FCM(ng/g)levels.Attention should be paid to noisy activities(e.g.,recreational activities for visitors in protected natural areas)and loud groups of people to conserve wildlife,especially noise sensitive species.展开更多
基金supported by the Key Project at the Central Government Level:the ability establishment of sustainable use for valuable Chinese medicine resources(No.2060302)the National Natural Science Foundation of China(No.82104389)+2 种基金the Scientific and Technological Innovation Project of China Academy of Chinese Medical Sciences(No.CI2023E002)the High-level Key Discipline Program of National Administration of Traditional Chinese Medicine(No.ZYYZDXK-2023244)China Agricultural Research System of MOF and MARA(No.CARS-21).
文摘Pyrrolizidine alkaloids(PAs)are natural toxins generated as secondarymetabolites in plants,predominantly consisting of unsaturated PAs with diverse toxicities,such as hepatotoxicity.Echimidine,a prominent PA,is believed to exert various toxicological effects,including survival inhibition and induction of apoptosis of hepatocytes.However,the effects of echimidine on development remain unclear.We selected three concentrations of 0.02,0.2,and 2 mg/L to investigate the developmental toxicity of echimidine on zebrafish embryos.After a 7-day exposure,we observed hyperactivity and anxiety-like behavior in zebrafish larvae.Furthermore,we found that echimidine exposure significantly promoted embryonic motor neurodevelopment in geneticallymodified zebrafish.Next,we detected that echimidine exposure significantly increased the content of the excitatory neurotransmitter acetylcholine(ACh),accompanied by a significant decrease in acetylcholinesterase(AChE)activity.Conversely,echimidine led to a significant reduction in the content of the sedative neurotransmitterγ-aminobutyric acid(GABA),accompanied by abnormal gene expression of enzymes related to GABA synthesis.Moreover,we elucidated the strong direct binding of echimidine to zebrafish and human AChE protein through molecular docking.In summary,our study found that echimidine induced ACh accumulation possibly by inhibiting AChE activity,leading to motor neurodevelopmental abnormalities and hyperactivity in zebrafish larvae.This work provides important scientific knowledge on the effects and mechanisms of PAs on neural development,which is helpful for controlling the risk of PAs in food and protecting public health.
基金supported by a grant from The Institute for Rehabilitation and Research Foundation,No.MC018-112(to PW)John S.Dunn Foundation,No.18168(to PW)+2 种基金the National Natural Science foundation of China,Nos.81620108018(to SQF),81930070(to SQF),82072439(to GZN)Tianjin Key Research and Development Plan,Key Projects For Science and Technology Support of China,No.19YFZCSY00660(to SQF)the National Key R&D Program of China,No.2019YFA0112100(to SQF).
文摘Metformin,a first-line drug for type-2 diabetes,has been shown to improve locomotor recovery after spinal cord injury.However,there are studies reporting no beneficial effect.Recently,we found that high dose of metformin(200 mg/kg,intraperitoneal)and acute phase administration(immediately after injury)led to increased mortality and limited locomotor function recovery.Consequently,we used a lower dose(100 mg/kg,i.p.)metformin in mice,and compared the effect of immediate administration after spinal cord injury(acute phase)with that of administration at 3 days post-injury(subacute phase).Our data showed that metformin treatment starting at the subacute phase significantly improved mouse locomotor function evaluated by Basso Mouse Scale(BMS)scoring.Immunohistochemical studies also revealed significant inhibitions of microglia/macrophage activation and astrogliosis at the lesion site.Furthermore,metformin treatment at the subacute phase reduced neutrophil infiltration.These changes were in parallel with the increased survival rate of spinal neurons in animals treated with metformin.These findings suggest that low-dose metformin treatment for subacute spinal cord injury can effectively improve the functional recovery possibly through anti-inflammation and neuroprotection.This study was approved by the Institute Animal Care and Use Committee at the University of Texas Medical Branch(approval No.1008041C)in 2010.
基金partially supported by the MBRS-RISE Program(R25 GM061838)MBRS-SCORE(SO6-GM08224)+2 种基金COBRE(5P20-GM103642)SNRP(NS39405)RCMI(8G12MD007600)
文摘The spinal cord has the ability to regenerate but the microenvironment generated after trauma reduces that capacity. An increase in Src family kinase （SFK） activity has been implicated in neuropathological conditions associated with central nervous system trauma. Therefore, we hypothesized that a decrease in SFK activation by a long-term treatment with 4-amino-5-（4- chlorophenyl）-7-（t-butyl）pyrazolo[3,4-d]pyramidine （PP2）, a selective SFK inhibitor, after spinal cord contusion with the New York University （NYU） impactor device would generate a permissive environment that improves axonal sprouting and/or behavioral activity. Results demonstrated that long-term blockade of SFK activation with PP2 increases locomotor activity at 7, 14, 21 and 28 days post-iniury in the Basso, Beattie, and Bresnahan open field test, round and square beam crossing tests. In addition, an increase in white matter spared tissue and serotonin fiber density was observed in animals treated with PP2. However, blockade of SFK activity did not change the astrocytic response or infiltration of cells from the immune system at 28 days post-injury. Moreover, a reduced SFK activity with PP2 diminished Ephexin （a guanine nudeotide exchange factor） phosphorylation in the acute phase （4 days post-injury） after trauma. Together, these findings suggest a potential role of SFK in the regulation of spared tissue and/or axonal outgrowth that may result in functional locomotor recovery during the pathophysiology generated after spinal cord injury. Our study also points out that ephexinl phosphorylation （activation） by SFK action may be involved in the repulsive microenvironment generated after spinal cord injury.
基金supported by grants from Innovative Team Project of Nanjing Normal University(Project No.0319PM0902)Priority Academic Program Development of Jiangsu Higher Education Institutions(CXLX11_0885)to Xiang JI
文摘Tail autotomy is a defense mechanism used by many lizards to evade predators, but it entails costs. We used the oriental leaf-toed gecko Hemidactylus bowringii as a model animal to evaluate locomotor costs of tail autotomy. We removed the tail about 5 mm from the tail base from each of the experimental geckos(adult males) initially having intact tails. Tailless experimental geckos and tailed control geckos were measured for overall speed and sprint speed in both vertical and horizontal directions. Overall speed and sprint speed did not differ between tailless and tailed geckos. The influence of locomotor direction on both overall speed and sprint speed was significant, with horizontal speed being greater than vertical speed. The interaction between tail condition and locomotor direction was not significant in overall speed, but was significant in sprint speed. Tailless geckos had faster vertical sprint speed than the tailed individuals. Of the 130 field-caught adults, 59 had previously lost their tails, with most(about 61%) of them shedding their tails near the tail base. Neither the proportion of geckos with tail autotomy nor the frequency distribution of locations of the tail break differed between the sexes. Our data show that tail loss of H. bowringii occurs frequently in nature. However, tail loss does not incur locomotor costs in this gecko.
文摘Objective:To evaluate the neuroprotective effects of the organic components of scallop shells(scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo(a,d) cyclohepten-5,10-imine(MK801).Methods:Effect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test,the Morris water maze test,and the open field test.Results:Scallop shell extract significantly reduced scopolamine-induced short-term memory impairment and partially reduced scopolamine-induced spatial memory impairment in the Morris water maze test.Scallop shell extract suppressed scopolamine-induced elevation of acetylcholine esterase activity in the cerebral cortex.Treatment with scallop shell extract reversed the increase in locomotor activity induced by scopolamine.Scallop shell extract also suppressed the increase in locomotor activity induced by MK801.Conclusions:Our results provide initial evidence that scallop shell extract reduces scopolamine-induced memory impairment and suppresses MK-801-induced hyperlocomotion.
基金supported by the Special Fund for Basic Scientific Research of Central Public Research Institutes of China,No.2015CZ-6,2016CZ-4a grant from the Beijing Institute for Brain Disorders,No.201601
文摘OBJECTIVE： To investigate the effects of myelotomy on locomotor recovery in rats subjected to spinal cord injury. DATA SOURCES： Electronic databases including Pub Med, Science Citation Index, Cochrane Library, China National Knowledge Infrastructure, Chinese Journals Full-text Database, China Biology Medicine disc, and Wanfang Database were searched to retrieve related studies published before September 2017. The Me SH terms（the Medical Subject Headings） such as ＂myelotomy＂, ＂spinal cord injuries＂, ＂rats＂, ＂randomized controlled trial＂ and all related entry terms were searched. DATA SELECTION： Randomized controlled trials using myelotomy for the treatment of acute spinal cord injury in rats were included. Basso, Beattie, and Bresnahan scores were adopted as the evaluation method. Rev Man Software（version 5.3） was used for data processing. The χ^2 and I^2 tests were used to assess heterogeneity. Using a random-effects model, a subgroup analysis was conducted to analyze the source of the heterogeneity. OUTCOME MEASURES： Basso, Beattie, and Bresnahan scores were observed 1–6 weeks after spinal cord injury.RESULTS： Six animal trials were included, using a total of 143 lab rats. The included trials were divided into two subgroups by injury degrees（moderate or severe）. The pooled results showed that, 1–6 weeks after spinal cord injury, the overall Basso, Beattie, and Bresnahan score was significantly higher in the myelotomy group than in the contusion group（weighted mean difference（WMD） = 0.60; 95% confidence interval（CI）： 0.23–0.97; P = 0.001; WMD = 2.10; 95% CI： 1.56–2.64; P 〈 0.001; WMD = 2.65; 95% CI： 1.73–3.57; P 〈 0.001; WMD = 1.66; 95% CI： 0.80–2.52; P 〈 0.001; WMD = 2.09; 95% CI： 0.92–3.26, P 〈 0.001; WMD = 2.25; 95% CI： 1.06–3.44, P 〈 0.001）. The overall heterogeneity was high（I^2 = 85%; I^2 = 95%; I^2 = 94%; I^2 = 88%; I^2 = 91%; I^2 = 89%）. The results in the moderate injury subgroup showed that Basso, Beattie, and Bresnahan scores were significantly higher in the myelotomy group than in the contusion group（WMD = 0.91, 95% CI： 0.52–1.3, P 〈 0.001; WMD = 2.10; 95% CI： 1.56–2.64, P 〈 0.001; WMD = 2.65; 95% CI： 1.73–3.57, P 〈 0.001; WMD = 2.50, 95% CI： 1.72–3.28, P 〈 0.001; WMD = 3.29, 95% CI： 2.21–4.38, P 〈 0.001; WMD = 3.27; 95% CI： 2.31–4.23, P 〈 0.001）. The relevant heterogeneity was low. However, there were no significant differences in Basso, Beattie, and Bresnahan scores between the myelotomy and contusion groups in the severe injury subgroup at 2 and 3 weeks after the injury（P = 0.75; P = 0.92）. CONCLUSION： To date, this is the first attempt to summarize the potential effect of myelotomy on locomotor recovery in rats with spinal cord injury. Our findings conclude that myelotomy promotes locomotor recovery in rats with spinal cord injury, especially in those with moderate injury.
文摘The significant influence of thermal acclimation on physiological and behavioral performance has been documented in many ectothermic animals, but such studies are still limited in turtle species. We acclimated hatchling soft-shelled turtles Pelodiscus sinensis under three thermal conditions （10, 20 and 30~C） for 4 weeks, and then measured selected body temperature （Tsel）, critical thermal minimum （CTMin） and maximum （CTM^x）, and locomotor performance at different body temperatures. Thermal acclimation significantly affected thermal preference and resistance of P sinensis hatchlings. Hatchling turtles accli- mated to 10~C selected relatively lower body temperatures and were less resistant to high temperatures than those acclimated to 20~C and 30~C. The turtles＇ resistance to low temperatures increased with a decreasing acclimation temperature. The thermal re- sistance range （i.e. the difference between CTM^x and CTMin, TRR） was widest in turtles acclimated to 20~C, and narrowest in those acclimated to 10~C. The locomotor performance of turtles was affected by both body temperature and acclimation tem- perature. Hatchling turtles acclimated to relatively higher temperatures swam faster than did those acclimated to lower temperatures. Accordingly, hatchling turtles acclimated to a particular temperature may not enhance the performance at that temperature. Instead, hatchlings acclimated to relatively warm temperatures have a better performance, supporting the ＂hotter is better＂ hypothesis.
基金the National Natural Science Foundation of China,No.30801222(to JZB).
文摘Oscillating field stimulation(OFS)is a potential method for treating spinal cord injury.Although it has been used in spinal cord injury(SCI)therapy in basic and clinical studies,its underlying mechanism and the correlation between its duration and nerve injury repair remain poorly understood.In this study,we established rat models of spinal cord contusion at T10 and then administered 12 weeks of OFS.The results revealed that effectively promotes the recovery of motor function required continuous OFS for more than 6 weeks.The underlying mechanism may be related to the effects of OFS on promoting axon regeneration,inhibiting astrocyte proliferation,and improving the linear arrangement of astrocytes.This study was approved by the Animal Experiments and Experimental Animal Welfare Committee of Capital Medical University(supplemental approval No.AEEI-2021-204)on July 26,2021.
文摘We studied the locomotor behaviour of white-headed langurs Trachypithecus leucocephalus and Francois＇ langurs T.francoisi to test two hypotheses： （1） these monkeys have evolved locomotor ability to support their activities on limestone hills, and （2） Francois＇ langurs have evolved more diverse locomotor skills than white-headed langurs. Data were collected from 1996 - 1998 and in 2005 in Fusui Nature Reserve, Guangxi, and showed that the two species had similar locomotor types, but Francois＇ langurs had more locomotor modes （26） than white-headed langurs （12）. Quadrupedal walking and leaping were two major types, and white-headed langurs were more arboreal than Francois＇ langurs. We suggest that, while keeping their ancestral locomotor types, the two species have evolved new types allowing them to live on limestone cliffs. Compared to white-headed langurs, Francois＇ langurs have more diverse locomotor modes that probably have allowed them to live in more habitat types. As an evolutionary outcome, Francois＇ langurs have a larger distribution range .
基金funded by the National Natural Science Foundation of China (Grant Nos. 31601870 and 51435008)Natural Science Foundation of Jiangsu Province, China (Grant No. SBK20160800 to Zhouyi WANG)Jiangsu Provincial Key Laboratory of Bionic Functional Materials
文摘Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the capture of flexible, small animals with complex locomotor behaviors, the markers interfere with each other easily, and the motion forms(bending, twisting) of the moving parts are obviously different;thus, it is a great challenge to realize accurate quantitative characterization of complex locomotor behaviors. The correlation between the marker properties, including the size and space length, and the precision of the system are revealed in this paper, and the effects of diverse marker shapes on the capturing accuracy of the captured objects in different motion forms were tested. Results showed that the precision of system is significantly improved when the ratio of the space length to the diameter of the markers is larger than four;for the capture of the spatial twisting motion of the flexible object, the hexagon markers had the lowest spatial lost-marker rate relative to the circle, triangle, and square. Customized markers were used to capture the locomotor behavior of the gecko-inspired robot(rigid connection) and the gecko(flexible connection). The results showed that this marking technology can achieve high accuracy of motion capture for geckos(the average deviation was approximately 0.32 mm, and the average deviation’s variation rate was approximately 0.96%). In this paper, the marking technology for the motion capture of flexible, small animals with complex motion is proposed;it can effectively improve the system precision as well as the capture accuracy, and realize the quantitative characterization of the complex motion of flexible, small objects. It provides a reliable technical means to deeply study the evolution of the motion function of small animals and advance systematic research of motion-capture technology.
文摘This study sought to elucidate the changes of nuclear factor kappa B （NF-KB） expression and locomotor function of hind limb after subdural injection of BMS-345541 was applied in rats with acute spinal cord injury. The results indicated that BMS-345541 treatment reduced the expression of NF-kB at 24 hours after injury, compared with normal saline-treated rats. This treatment also led to a significant improvement in locomotor functional recovery at 14 days after injury. Overall, the findings demonstrated that BMS-345541 significantly ameliorated spinal cord injury-induced hind limb dysfunction by inhibiting the expression of NF-kB after spinal cord injury.
基金supported in part by a grant from the Fondation pour la Recherche Médicale (DNC20101021008)
文摘Recovery of locomotor behavior following spinal cord injury can occur spontaneously in some vertebrates, such as fish, urodele amphibians, and certain reptiles. This review provides an overview of the current status of our knowledge on the anatomical and electrophysiological changes occurring within the spinal cord that lead to, or are associated with the [e-expression of locomotion in spinally-transected salamanders. A better understanding of these processes will help to devise strategies for restoring locomotor function in mammals, including humans.
基金supported by the Manitoba Health Research Council Foundationthe Canadian Institutes of Health Research Foundationthe Health Science Centre Foundation
文摘Chronic long-term exposure to cuprizone causes severe brain demyelination in mice,which leads to changes in locomotion,working memory and anxiety.These findings suggest the importance of intact myelin for these behaviors.This study aimed to investigate the possible behavioral changes in mice with mild oligodendrocyte/myelin damage that parallels the white matter changes seen in the brains of patients with psychiatric disporders.We used the cuprizonetreated mouse model to test both tissue changes and behavioral functions（locomotor activity,anxiety status,and spatial working memory）.The results showed that mice given cuprizone in their diet for 7 days had no significant myelin breakdown as evaluated by immunohistochemical staining for myelin basic protein,while the number of mature oligodendrocytes was reduced.The number and length of Caspr protein clusters,a structural marker of the node of Ranvier,did not change.The locomotor activity of the cuprizonetreated mice increased whereas their anxiety levels were lower than in normal controls;spatial working memory,however,did not change.These results,for the first time,link emotion-related behavior with mild white matter damage in cuprizone-treated mice.
基金supported by grants from the Training Program for Young Backbone Teachers of Yunnan University, the Research Foundation of Yunnan University (2011YB22)the Natural Science Foundation of Yunnan Province, China (2011FZ012)+5 种基金the Special Fund of the "211" Third Phase Project of Yunnan University (21134018)a National Project (2007ZDGGKVST003)a Provincial National Project (2008CA012-5)National Basic Research Development Program (973 program) of China (2012CB825500, 2011CB70780)National Natural Science Foundation of China (31271168)"Strategic Priority Research Program" of the Chinese Acedemy of Sciences, China (XD B02020500)
文摘Morphine can modulate the processes underlying memory in vertebrates. However, studies have shown various modulations by morphine： positive, negative and even neutral. The honeybee is a potential platform for evaluating the effects of drugs, especially addictive drugs, on the nervous system. However, the involvement of morphine in learning and memory in insects or other invertebrates is poorly understood. The current work evaluated whether morphine affects memory acquisition, consolidation and retrieval in honeybees, using the proboscis extension response （PER） paradigm. We demonstrated that morphine treatment （5 pg/bee） before training decreased the percentage of correct PERs and the response latency related to aversive rather than rewarding odors when tested after 1 or 24 h. Morphine treatment after training also caused a decrease in this latency when tested after 24 h. Meanwhile, morphine treatment reduced the ambulation distance when tested after 30 min. Our findings suggest that morphine impairs the acquisition of shortand long-term associative memory and slightly disrupts the consolidation of long-term memory in honeybees. These negative effects cannot be explained by reduced locomotion but by impaired memory associated with aversion.
基金supported by a grant from National Institute of Health(NIH)Grant No.NS040433
文摘Amyotrophic lateral sclerosis is a motoneuron degenerative disease that is challenging to diagnose and presents with considerable variability in survival.Early identification and enhanced understanding of symptomatic patterns could aid in diagnosis and provide an avenue for monitoring disease progression.Use of the m SOD1 G93 A mouse model provides control of the confounding environmental factors and genetic heterogeneity seen in amyotrophic lateral sclerosis patients,while investigating underlying disease-induced changes.In the present study,we performed a longitudinal behavioral assessment paradigm and identified an early hindlimb symptom,resembling the common gait abnormality foot drop,along with an accompanying forelimb compensatory mechanism in the m SOD1 G93 A mouse.Following these initial changes,m SOD1 mice displayed a temporary hindlimb compensatory mechanism resembling an exaggerated steppage gait.As the disease progressed,these compensatory mechanisms were not sufficient to sustain fundamental locomotor parameters and more severe deficits appeared.We next applied these initial findings to investigate the inherent variability in B6 SJL m SOD1 G93 A survival.We identified four behavioral variables that,when combined in a cluster analysis,identified two subpopulations with different disease progression rates：a fast progression group and a slow progression group.This behavioral assessment paradigm,with its analytical approaches,provides a method for monitoring disease progression and detecting m SOD1 subgroups with different disease severities.This affords researchers an opportunity to search for genetic modifiers or other factors that likely enhance or slow disease progression.Such factors are possible therapeutic targets with the potential to slow disease progression and provide insight into the underlying pathology and disease mechanisms.
基金supported by the National Natural Science Foundation of China (81371400 and 81071026)the National Basic Research Development Program of China (2013CB530900)the Key Discipline of Chongming County and Shanghai Institute of Health Science, China (FY(14)700-A5-1-19)
文摘The negative-geotaxis climbing assay is used to efficiently study aging and neurodegeneration in Drosophila.To make it suitable for large-scale study,a method called the rapid iterative negative geotaxis（RING） assay has been established by simultaneously photographing the climbing of multiple groups of flies when they are manually tapped down in test tubes.Here,we automated the assay by using a well-controlled electric motor to drive the tapping,and a homemade program to analyze the climbing height of flies.Using the automated RING（aRING） assay,we found that the climbing ability of a strain of wild-type flies,males in particular,declined rapidly before day 21 after eclosion,but slowly from day 21 to 35.We also found that the expression of arctic mutant Aβ_（42） accelerated the age-dependent decline in the climbing ability of flies.Moreover,using aRING,we examined the effect of third chromosome deficiencies on the accelerated locomotor decline in Aβ_（42）-expressing flies,and isolated 7 suppressors and15 enhancers.
基金Startup Fund for scientific research,Fujian Medical University,Grant/Award Number:2020QH1039Joint Funds for the Innovation of Science and Technology,Fujian Province,Grant/Award Number:2020Y9114 and 2020Y9119。
文摘The rodent running-wheel recording apparatus is a reliable approach for studying cir-cadian rhythm.This study demonstrated how to construct a simple and intelligent running-wheel recording system.The running wheel was attached to the cage's base,whereas the Hall sensor was attached to the cage's cover.Then,the RJ25 adaptor relayed the running signal to the main control board.Finally,the main control board was connected to the USB port of the computer with the USB connection.Data were collected using the online-accessible,self-created software Magturning.Through Magturning,generated data were saved and exported in real time.Afterward,the device was validated by collecting data on the locomotor activities of mice under dif-ferent light conditions.In conclusion,this new device can record circadian activity of rodents.Our device is appropriate for interdisciplinary investigations related to biological clock research.
文摘Previous social experience may affect subsequent behavior. It was shown by other authors that Drosophila melanogaster males kept individually are more aggressive and sexually active than males kept in a group. In the present study, we tested the locomotor activity of individual males and females previously reared either individually, or in a group. We found that keeping 20 young males for three days together led to a strong long-term (up to 5 days) reduction in their further locomotor activity as individuals. Rearing of young males in groups of other sizes (2, 5, 10, and 30) produced a smaller or no after-effect. At the same time, we have not found any difference in subsequent behavior of individual females previously kept either individually, or in a group. We suppose that in a group, flies learned to suppress their locomotor activity to prevent unpleasant contacts with other animals (operant learning). It seems that in males this learning is more efficient because of the higher level of aggression producing the stronger negative reinforcement.
文摘There are no reports on the effect of amphetamine on female WKY circadian activity pattern. The objective of this study is to investigate whether repeated daily exposure to the psychostimulant amphetamine alters the locomotor circadian rhythm activity patterns of female adult Wistar-Kyoto (WKY) rats. Twenty-four rats were divided into two groups, control (N = 12) and experimental (N = 12), and kept in a 12:12 h light/dark cycle in an open field cage. After 5 to 7 days of acclimation, 11 days of consecutive non-stop recordings began. On experimental day 1, all groups were given an injection of saline. On experimental days 2 to 7, the experimental group was injected with 0.6 mg/kg amphetamine and the control group with saline followed by a washout phase from experimental day 8 to 10, and amphetamine re-challenge or saline on experimental day 11 similar to experimental day 2. Locomotor movements were determined using a computerized animal activity monitoring system, and cosine statistical analysis was used to fit a24-hour curve to the activity pattern. The horizontal activity (HA), total distance (TD), number of stereotypy (NOS), and stereotypical movements (SM) were analyzed for alterations in the circadian rhythm activity patterns. The data demonstrated that chronic amphetamine administration alters the mesor parameter of the circadian rhythm activity patterns, indicating that chronic amphetamine treatment exerts long term effects on these rats.
基金This research was funded by the authors with help from Fundacion para la Investigacion en Etologıa y Biodiversidad(FIEB),who funded a small portion of the hormonal analyzes.
文摘Human activities involving noise emission can affect wild animals.European mink was exposed to road noise and human voice playbacks to analyze how sound intensity level and duration of both noises altered the time that individuals were active and if their fecal cortisol metabolite(FCM)levels varied.A Hierarchical Analysis Cluster was performed to establish 2 mink groups with respect to both noise source type:short duration/low intensity(SL)and long duration/high intensity(LH).We performed general linear mixed models to evaluate the variation in locomotor activity duration(s)and FCM(nanogram per gram)levels,respectively.The results showed both road noise and human voices decreased locomotor activity duration in SL more sharply compared with LH,and human voices were the triggers that induced the most pronounced response to both exposure conditions.FCM(ng/g)levels increased in SL compared with LH during road noise while the opposite happened during human voices.Differences based on sex and age of individuals were observed.In conclusion,noise characteristics given by the sound type determined the variations in locomotor activity duration while noise exposure level determined the variations in FCM(ng/g)levels.Attention should be paid to noisy activities(e.g.,recreational activities for visitors in protected natural areas)and loud groups of people to conserve wildlife,especially noise sensitive species.
