Dear Editor,The importance of the medial entorhinal cortex(MEC)for memory and spatial navigation has been shown repeatedly in many species,including mice and humans[1,2].It is,therefore,not surprising that the connect...Dear Editor,The importance of the medial entorhinal cortex(MEC)for memory and spatial navigation has been shown repeatedly in many species,including mice and humans[1,2].It is,therefore,not surprising that the connectivity of this structure has been studied extensively over the past century,mainly using a range of anterograde and retrograde anatomical tracers[3].展开更多
Humans and animals have a fundamental ability to use experiences and environmental information to organize behavior.It often happens that humans and animals make decisions and prepare actions under uncertain situation...Humans and animals have a fundamental ability to use experiences and environmental information to organize behavior.It often happens that humans and animals make decisions and prepare actions under uncertain situations.Uncertainty would significantly affect the state of animals’minds,but may not be reflected in behavior.How to“read animals’mind state”under different situations is a challenge.Here,we report that neuronal activity in the medial prefrontal cortex(mPFC)of rats can reflect the environmental uncertainty when the task situation changes from certain to uncertain.Rats were trained to perform behavioral tasks under certain and uncertain situations.Under certain situations,rats were required to simply repeat two nose-poking actions that each triggered short auditory tone feedback(single-task situation).Whereas under the uncertain situation,the feedback could randomly be either the previous tone or a short musical rhythm.No additional action was required upon the music feedback,and the same secondary nose-poking action was required upon the tone feedback(dual-task situation);therefore,the coming task was uncertain before action initiation.We recorded single-unit activity from the mPFC when the rats were performing the tasks.We found that in the dual task,when uncertainty was introduced,many mPFC neurons were actively engaged in dealing with the uncertainty before the task initiation,suggesting that the rats could be aware of the task situation change and encode the information in the mPFC before the action of task initiation.展开更多
Anxiety disorder is a major symptom of autism spectrum disorder(ASD)with a comorbidity rate of~40%.However,the neural mechanisms of the emergence of anxiety in ASD remain unclear.In our study,we found that hyperactivi...Anxiety disorder is a major symptom of autism spectrum disorder(ASD)with a comorbidity rate of~40%.However,the neural mechanisms of the emergence of anxiety in ASD remain unclear.In our study,we found that hyperactivity of basolateral amygdala(BLA)pyramidal neurons(PNs)in Shank3 InsG3680 knock-in(InsG3680+/+)mice is involved in the development of anxiety.Electrophysiological results also showed increased excitatory input and decreased inhibitory input in BLA PNs.Chemogenetic inhibition of the excitability of PNs in the BLA rescued the anxiety phenotype of InsG3680+/+mice.Further study found that the diminished control of the BLA by medial prefrontal cortex(mPFC)and optogenetic activation of the mPFC-BLA pathway also had a rescue effect,which increased the feedforward inhibition of the BLA.Taken together,our results suggest that hyperactivity of the BLA and alteration of the mPFC-BLA circuitry are involved in anxiety in InsG3680+/+mice.展开更多
Objective The ventral part of the medial prefrontal cortex（mPFC）plays an important role in initiation and control of voluntary movement,mood and cognition.However,after the degeneration of the nigrostriatal pathway,...Objective The ventral part of the medial prefrontal cortex（mPFC）plays an important role in initiation and control of voluntary movement,mood and cognition.However,after the degeneration of the nigrostriatal pathway,the neuronal activity of the ventral mPFC and the role of serotonin1A（5-hydroxytryptamine,5-HT1A）receptors in the firing of the neurons are still unknown.The present study is to investigate the change of neuronal activity in the ventral mPFC and the effect of systemic administration of the selective 5-HT1Areceptor antagonist WAY-100635 on the activity of the neurons in normal and 6-hydroxydopamine（6-OHDA）-lesioned rats.Methods Single unit responses were recorded extracellularly with glass microelectrodes from ventral mPFC neurons in normal rats and 6-OHDA unilaterally lesiond rats in vivo.Results 6-OHDA lesion of the substantia nigra pars compacta（SNc）significantly increased the firing rate with no change in the firing pattern of neurons of the ventral mPFC in rats.Systemic administration of WAY-100635（0.1 mg/kg,i.v.）did not change the mean firing rate and firing pattern of ventral mPFC neurons in normal rats.In contrast,WAY-100635 signifi- cantly decreased the mean firing rate of the neurons in rats with 6-OHDA lesion of the SNc.Conclusion These data suggest that the degeneration of the nigrostriatal pathway results in an increase of neuronal activity of ventral mPFC and dysfunction of 5-HT1Areceptor.展开更多
Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role. This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a ...Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role. This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a working memory task and to explore how a neuronal ensemble encodes a working memory event. Methods Sprague-Dawley rats were trained in a Y-maze until they reached an 80% correct rate in a working memory task. Then a 16-channel microelectrode array was implanted in the prefrontal cortex. After recovery, neuronal population activity was recorded during the task, using the Cerebus data-acquisition system. Spatio-temporal trains of action potentials were obtained from the original neuronal population signals. Results During the Y-maze working memory task, some neurons showed significantly in- creased firing rates and evident neuronal ensemble activity. Moreover, the anticipatory activity was associated with the delayed alternate choice of the upcoming movement. In correct trials, the averaged pre-event firing rate （10.86 ± 1.82 spikes/ bin） was higher than the post-event rate （8.17 ± 1.15 spikes/bin） （P 〈0.05）. However, in incorrect trials, the rates did not differ. Conclusion The results indicate that the anticipatory activity of a neuronal ensemble in the prefrontal cortex may play a role in encoding working memory events.展开更多
BACKGROUND In intertrochanteric fractures,the positive medial cortex support reduction is considered to provide a non-anatomical buttress that helps in controlled collapse.AIM To analyze the concept of medial cortical...BACKGROUND In intertrochanteric fractures,the positive medial cortex support reduction is considered to provide a non-anatomical buttress that helps in controlled collapse.AIM To analyze the concept of medial cortical reduction(MCR)and its clinical and radiological association in geriatric intertrochanteric femur fractures.METHODS Geriatric patients who presented with AO/OTA 31A1 and 31A2 femur fractures and treated with proximal femoral nailing between July 2021 and June 2023 were include in this prospective cohort study.Based on the degree of MCR,they were divided into positive,neutral,or negative MCR groups.The demographic baseline characteristics,postoperative radiographic femoral neck-shaft angle and neck length were analyzed at 6,12 and 24 weeks post-surgery.Functional outcomes such as modified Harris Hip Score(HHS)and time to full-weight bearing were also analyzed.RESULTS 47 patients(Male:Famale 35:12)with mean age of 65.8±4.2 years were included in this study.Twenty-two cases had neutral support,nine had negative support,and sixteen had positive support in the medial cortex postoperatively.Baseline characteristics of the three groups were comparable.No significant differences were found in the femur neck length and femur neck-shaft angle changes post-surgery between the groups.The modified HHS was not found to be significant between the groups(P=0.883)as that of the time to full weight bearing(P=0.789).CONCLUSION The type of reduction achieved based on medial cortical alignment does not affect the femur neck length shortening or varus collapse.Future randomized controlled trials are needed to validate the findings noted in the study.展开更多
The aim of this study was to investigate proton magnetic resonance spectroscopy metabolite values in the medial prefrontal cortex of individuals with euthymic bipolar disorder. The subjects consisted of 15 patients wi...The aim of this study was to investigate proton magnetic resonance spectroscopy metabolite values in the medial prefrontal cortex of individuals with euthymic bipolar disorder. The subjects consisted of 15 patients with euthymic bipolar disorder type I and 15 healthy controls. We performed proton magnetic resonance spectroscopy of the bilateral medial prefrontal cortex and measured levels of N-acetyl aspartate, choline and creatine. Levels of these three metabolites in the medial prefrontal cortex were found to be lower in patients with bipolar disorder compared with healthy controls. A positive correlation was found between illness duration and choline levels in the right medial prefrontal cortex. Our study suggests that during the euthymic period, there are abnormalities in cellular energy and membrane phospholipid metabolism in the medial prefrontal cortex, and that this may impair neuronal activity and integrity.展开更多
Methyl-CpG binding protein 2(MeCP2) is a basic nuclear protein involved in the regulation of gene expression and microRNA processing.Duplication of MECP2-containing genomic segments causes MECP2 duplication syndrome,a...Methyl-CpG binding protein 2(MeCP2) is a basic nuclear protein involved in the regulation of gene expression and microRNA processing.Duplication of MECP2-containing genomic segments causes MECP2 duplication syndrome,a severe neurodevelopmental disorder characterized by intellectual disability,motor dysfunction,heightened anxiety,epilepsy,autistic phenotypes,and early death.Reversal of the abnormal phenotypes in adult mice with MECP2 duplication(MECP2-TG) by normalizing the MeCP2 levels across the whole brain has been demonstrated.However,whether different brain areas or neural circuits contribute to different aspects of the behavioral deficits is still unknown.Here,we found that MECP2-TG mice showed a significant social recognition deficit,and were prone to display aversive-like behaviors,including heightened anxiety-like behaviors and a fear generalization phenotype.In addition,reduced locomotor activity was observed in MECP2-TG mice.However,appetitive behaviors and learning and memory were comparable in MECP2-TG and wild-type mice.Functional magnetic resonance imaging illustrated that the differences between MECP2-TG and wild-type mice were mainly concentrated in brain areas regulating emotion and social behaviors.We used the CRISPR-Cas9 method to restore normal MeCP2 levels in the medial prefrontal cortex(mPFC) and bed nuclei of the stria terminalis(BST) of adult MECP2-TG mice,and found that normalization of MeCP2 levels in the mPFC but not in the BST reversed the social recognition deficit.These data indicate that the mPFC is responsible for the social recognition deficit in the transgenic mice,and provide new insight into potential therapies for MECP2 duplication syndrome.展开更多
Object:Early-life neglect has irreversible emotional effects on the central nervous system.In this work,we aimed to elucidate distinct functional neural changes in me-dial prefrontal cortex(mPFC)of model rats.Methods:...Object:Early-life neglect has irreversible emotional effects on the central nervous system.In this work,we aimed to elucidate distinct functional neural changes in me-dial prefrontal cortex(mPFC)of model rats.Methods:Maternal separation with early weaning was used as a rat model of early-life neglect.The excitation of glutamatergic and GABAergic neurons in rat mPFC was recorded and analyzed by whole-cell patch clamp.Results:Glutamatergic and GABAergic neurons of mPFC were distinguished by typi-cal electrophysiological properties.The excitation of mPFC glutamatergic neurons was significantly increased in male groups,while the excitation of mPFC GABAergic neurons was significant in both female and male groups,but mainly in terms of rest membrane potential and amplitude,respectively.Conclusions:Glutamatergic and GABAergic neurons in medial prefrontal cortex showed different excitability changes in a rat model of early-life neglect,which can contribute to distinct mechanisms for emotional and cognitive manifestations.展开更多
Tibetan singing bowls emit low-frequency sounds and produce perceptible harmonic tones and vibrations through manual tapping.The sounds the singing bowls produce have been shown to enhance relaxation and reduce anxiet...Tibetan singing bowls emit low-frequency sounds and produce perceptible harmonic tones and vibrations through manual tapping.The sounds the singing bowls produce have been shown to enhance relaxation and reduce anxiety.However,the underlying mechanism remains unclear.In this study,we used chronic restraint stress or sleep deprivation to establish mouse models of anxiety that exhibit anxiety-like behaviors.We then supplied treatment with singing bowls in a bottomless cage placed on the top of a cushion.We found that unlike in humans,the combination of harmonic tones and vibrations did not improve anxietylike behaviors in mice,while individual vibration components did.Additionally,the vibration of singing bowls increased the level of N-methyl-D-aspartate receptor 1 in the somatosensory cortex and prefrontal cortex of the mice,decreased the level ofγ-aminobutyric acid A(GABA)receptorα1 subtype,reduced the level of CaMKII in the prefrontal cortex,and increased the number of GABAergic interneurons.At the same time,electrophysiological tests showed that the vibration of singing bowls significantly reduced the abnormal low-frequency gamma oscillation peak frequency in the medial prefrontal cortex caused by stress restraint pressure and sleep deprivation.Results from this study indicate that the vibration of singing bowls can alleviate anxiety-like behaviors by reducing abnormal molecular and electrophysiological events in somatosensory and medial prefrontal cortex.展开更多
Social hierarchy greatly influences behavior and health.Both human and animal studies have signaled the medial prefrontal cortex(mPFC)as specifically related to social hierarchy.Dopamine D1 receptors(D1Rs)and D2 recep...Social hierarchy greatly influences behavior and health.Both human and animal studies have signaled the medial prefrontal cortex(mPFC)as specifically related to social hierarchy.Dopamine D1 receptors(D1Rs)and D2 receptors(D2Rs)are abundantly expressed in the mPFC,modulat-ing its functions.However,it is unclear how DR-expressing neurons in the mPFC regulate social hierarchy.Here,using a confrontation tube test,we found that most adult C57BL/6J male mice could establish a linear social rank after 1 week of cohabitation.Lower rank individuals showed social anxiety together with decreased serum testosterone levels.D2R expression was significantly downregulated in the dorsal part of mPFC(dmPFC)in lower rank individuals,whereas D1R expression showed no significant difference among the rank groups in the whole mPFC.Virus knockdown of D2Rs in the dmPFC led to mice being particularly prone to lose the contests in the confrontation tube test.Finally,simultaneous D2R activation in the subordinates and D2R inhibition in the dominants in a pair switched their dominant-subordinate relationship.The above results indicate that D2Rs in the dmPFC play an important role in social dominance.Our findings provide novel insights into the divergent func-tions of prefrontal D1Rs and D2Rs in social dominance,which may contribute to ameliorating social dysfunctions along with abnormal social hierarchy.展开更多
Medial orbitofrontal cortex （mOFC） abnormalities have been observed in various anxiety disorders. However, the relationship between mOFC activity and anxiety among the healthy population has not been fully examined....Medial orbitofrontal cortex （mOFC） abnormalities have been observed in various anxiety disorders. However, the relationship between mOFC activity and anxiety among the healthy population has not been fully examined. Here, we conducted a resting state functional magnetic resonance imaging （R-fMRI） study with 56 healthy male adults from the Nathan Kline Institute/Rockland Sample （NKI-RS） to examine the relationship between the fractional amplitude of low-frequency fluctuation （fALFF） signals and trait anxiety across the whole brain. A Louvain method for module detection based on graph theory was further employed in the automated functional subdivision to explore subregional correlates of trait anxiety. The results showed that trait anxiety was related to fALFF in the mOFC. Additionally, the resting-state functional connectivity （RSFC） between the right subregions of the mOFC and the precuneus was correlated with trait anxiety. These findings provided evidence about the involvement of the mOFC in anxiety processing among the healthy population.展开更多
The dysfunction of the medial prefrontal cortex is associated with affective disorders and non-motor features in Parkinson’s disease.However,the exact role of the mediodorsal thalamic nucleus in the function of the p...The dysfunction of the medial prefrontal cortex is associated with affective disorders and non-motor features in Parkinson’s disease.However,the exact role of the mediodorsal thalamic nucleus in the function of the prefrontal cortex remains unclear.To study the possible effects of the mediodorsal thalamic nucleus on the neurological function of the medial prefrontal cortex,a model of Parkinson’s disease was established by injecting 8μg 6-hydroxydopamine into the substantia nigra compacta of rats.After 1 or 3 weeks,0.3μg ibotenic acid was injected into the mediodorsal thalamic nucleus of the midbrain.At 3 or 5 weeks after the initial injury,neuronal discharge in medial prefrontal cortex of rat brain was determined electrophysiologically.The numbers of dopamine-positive neurons and tyrosine hydroxylase immunoreactivity in substantia nigra compacta and ventral tegmental area were detected by immunohistochemical staining.Results demonstrated that after injury,the immunoreactivity of dopamine neurons and tyrosine hydroxylase decreased in the substantia nigra compacta and ventral tegmental areas of rats.Compared with normal medial prefrontal cortical neurons,at 3 and 5 weeks after substantia nigra compacta injury,the discharge frequency of pyramidal neurons increased and the discharge pattern of these neurons tended to be a burst-discharge,with an increased discharge interval.The discharge frequency of interneurons decreased and the discharge pattern also tended to be a burst-discharge,but the discharge interval was only higher at 3 weeks.At 3 weeks after the combined lesions,the discharge frequency,discharge pattern and discharge interval were restored to a normal level in pyramidal neurons and interneurons in medial prefrontal cortex.These findings have confirmed that mediodorsal thalamic nucleus is involved in regulating neuronal activities of the medial prefrontal cortex.The changes in the function of the mediodorsal thalamic nucleus may be associated with the abnormal discharge activity of the medial prefrontal cortex neurons after substantia nigra compacta injury.All experimental procedures were approved by the Institutional Animal Care and Use Committee of Xi’an Jiaotong University,China(approval No.XJTULAC2017-067)on August 26,2017.展开更多
Nicotine addiction is a concern worldwide.Most mechanistic investigations are on nicotine substance dependence properties based on its pharmacological effects.However,no effective therapeutic treatment has been establ...Nicotine addiction is a concern worldwide.Most mechanistic investigations are on nicotine substance dependence properties based on its pharmacological effects.However,no effective therapeutic treatment has been established.Nicotine addiction is reinforced by environments or habits.We demonstrate the neurobiological basis of the behavioural aspect of nicotine addiction.We utilized the conditioned place preference to establish nicotine-associated behavioural preferences(NABP)in rats.Brain-wide neuroimaging analysis revealed that the medial prefrontal cortex(mPFC)was activated and contributed to NABP.Chemogenetic manipulation ofµ-opioid receptor positive(MOR+)neurons in the mPFC or the excitatory outflow to the nucleus accumbens shell(NAcShell)modulated the NABP.Electrophysiological recording confirmed that the MOR+neurons directly regulate the mPFC-NAcShell circuit via GABAA receptors.Thus,the MOR+neurons in the mPFC modulate the formation of behavioural aspects of nicotine addiction via direct excitatory innervation to the NAcShell,which may provide new insight for the development of effective therapeutic strategies.展开更多
Introduction: Transcranial Magnetic Stimulation (TMS) is a non-invasive technique for brain stimulation. Repetitive TMS (rTMS) over the medial Prefrontal Cortex (mPFC), Broadman Area 10 (BA10) may stimulate transynapt...Introduction: Transcranial Magnetic Stimulation (TMS) is a non-invasive technique for brain stimulation. Repetitive TMS (rTMS) over the medial Prefrontal Cortex (mPFC), Broadman Area 10 (BA10) may stimulate transynaptically perigenual Anterior Cingulate Cortex (pACC, BA 33), insula, amigdala, hypothalamus and connected branches of the Autonomic Nervous System (ANS) involved in stressorevoked cardiovascular reactivity. Stressors are associated with an increase in sympathetic cardiac control, a decrease in parasympathetic control, or both, and, consequently, an increase in systolic/stroke volume, total vascular impedance/resistance and heart rate, a decrease of baroreflex sensitivity, i.e., an increase in blood pressure/arterial tension. Objectives and Aims: The present work aims, using TMS and accordingly to Gianaros modeling, based on functional neuroimaging studies and previous neuroanatomical data from animal models, to probe the connectivity of brain systems involved in stressor-evoked cardiovascular reactivity and to explore TMS potential as a tool for detection and stratification of individual differences concerning this reactivity and hemorreological risk factors correlated with the development of Coronary Heart Disease (CHD). Methods: Both subjects, a 52 years old male and a 40 years old female with previous increased Low Frequency (LF)/High Frequency (HF) Heart Rate Variability (HRV) ratios (respectively, 4.209/3.028) without decompensated cardiorespiratory symptoms, gave informed consent, and ethico-legal issues have been observed. Electroencephalographic (EEG) monitoring has been performed for safety purposes. Immediately after administration, over the mPFC, of 15 pulses of rTMS, during 60 second, with an inductive electrical current, at the stimulating coil, of 85.9 Ampère per μsecond and 66 Ampère per μsecond, respectively, for male and female subjects (a “figure-of-eight” coil and magnetic stimulator MagLite, Dantec/Medtronic, have been used), HRV spectrum analysis (cStress software) has been performed (during 5 minutes, in supine position). Results: In both subjects, LF power, HF power and LF/HF ratio results, before and after rTMS administration, pointed towards sympathetic attenuation and parasympathetic augmentation (respectively, in male/female subject: decreased LF power—65.1 nu/69.3 nu, before rTMS;56.1 nu/41.6 nu, after rTMS;increased HF power—15.5 nu/22.9 nu, before rTMS;30.9 nu/45.5 nu, after rTMS). Conclusions: In this preliminary investigation, the existence of a link between “mind” and heart’s function has been put in evidence, through a reversible “virtual” lesion, of brain systems involved in cardiovascular control, caused by TMS. Repetitive TMS over mPFC decreased brain function involved in stressorevoked cardiovascular reactivity, suggesting the importance of TMS in the management of stress-related cardiovascular disorders.展开更多
文摘Dear Editor,The importance of the medial entorhinal cortex(MEC)for memory and spatial navigation has been shown repeatedly in many species,including mice and humans[1,2].It is,therefore,not surprising that the connectivity of this structure has been studied extensively over the past century,mainly using a range of anterograde and retrograde anatomical tracers[3].
基金supported by the National Natural Science Foundation of China(32060199,32360197,31971035,and 31771182)the Jiangxi Province Natural Science Foundation(20224ACB206016).
文摘Humans and animals have a fundamental ability to use experiences and environmental information to organize behavior.It often happens that humans and animals make decisions and prepare actions under uncertain situations.Uncertainty would significantly affect the state of animals’minds,but may not be reflected in behavior.How to“read animals’mind state”under different situations is a challenge.Here,we report that neuronal activity in the medial prefrontal cortex(mPFC)of rats can reflect the environmental uncertainty when the task situation changes from certain to uncertain.Rats were trained to perform behavioral tasks under certain and uncertain situations.Under certain situations,rats were required to simply repeat two nose-poking actions that each triggered short auditory tone feedback(single-task situation).Whereas under the uncertain situation,the feedback could randomly be either the previous tone or a short musical rhythm.No additional action was required upon the music feedback,and the same secondary nose-poking action was required upon the tone feedback(dual-task situation);therefore,the coming task was uncertain before action initiation.We recorded single-unit activity from the mPFC when the rats were performing the tasks.We found that in the dual task,when uncertainty was introduced,many mPFC neurons were actively engaged in dealing with the uncertainty before the task initiation,suggesting that the rats could be aware of the task situation change and encode the information in the mPFC before the action of task initiation.
基金supported by grants from the National Natural Science Foundation of China(31970902,U22A20306,and 3192010300)the Municipal Administration of Hospitals Incubating Program(PZ2023009)+1 种基金the Key-Area R&D Program of Guangdong Province(2019B030335001)the Autism Research Special Fund of Zhejiang Foundation for Disabled Persons(2022003).
文摘Anxiety disorder is a major symptom of autism spectrum disorder(ASD)with a comorbidity rate of~40%.However,the neural mechanisms of the emergence of anxiety in ASD remain unclear.In our study,we found that hyperactivity of basolateral amygdala(BLA)pyramidal neurons(PNs)in Shank3 InsG3680 knock-in(InsG3680+/+)mice is involved in the development of anxiety.Electrophysiological results also showed increased excitatory input and decreased inhibitory input in BLA PNs.Chemogenetic inhibition of the excitability of PNs in the BLA rescued the anxiety phenotype of InsG3680+/+mice.Further study found that the diminished control of the BLA by medial prefrontal cortex(mPFC)and optogenetic activation of the mPFC-BLA pathway also had a rescue effect,which increased the feedforward inhibition of the BLA.Taken together,our results suggest that hyperactivity of the BLA and alteration of the mPFC-BLA circuitry are involved in anxiety in InsG3680+/+mice.
基金the National Natural Science Foundation of China（No.30370464） ；the Science and Technological Program of Shaanxi Province,China（No.2005K13-G6）
文摘Objective The ventral part of the medial prefrontal cortex（mPFC）plays an important role in initiation and control of voluntary movement,mood and cognition.However,after the degeneration of the nigrostriatal pathway,the neuronal activity of the ventral mPFC and the role of serotonin1A（5-hydroxytryptamine,5-HT1A）receptors in the firing of the neurons are still unknown.The present study is to investigate the change of neuronal activity in the ventral mPFC and the effect of systemic administration of the selective 5-HT1Areceptor antagonist WAY-100635 on the activity of the neurons in normal and 6-hydroxydopamine（6-OHDA）-lesioned rats.Methods Single unit responses were recorded extracellularly with glass microelectrodes from ventral mPFC neurons in normal rats and 6-OHDA unilaterally lesiond rats in vivo.Results 6-OHDA lesion of the substantia nigra pars compacta（SNc）significantly increased the firing rate with no change in the firing pattern of neurons of the ventral mPFC in rats.Systemic administration of WAY-100635（0.1 mg/kg,i.v.）did not change the mean firing rate and firing pattern of ventral mPFC neurons in normal rats.In contrast,WAY-100635 signifi- cantly decreased the mean firing rate of the neurons in rats with 6-OHDA lesion of the SNc.Conclusion These data suggest that the degeneration of the nigrostriatal pathway results in an increase of neuronal activity of ventral mPFC and dysfunction of 5-HT1Areceptor.
基金supported by the National Natural Science Foundation of China(61074131,91132722)the Doctoral Fund of the Ministry of Education of China(20101202110007)
文摘Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role. This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a working memory task and to explore how a neuronal ensemble encodes a working memory event. Methods Sprague-Dawley rats were trained in a Y-maze until they reached an 80% correct rate in a working memory task. Then a 16-channel microelectrode array was implanted in the prefrontal cortex. After recovery, neuronal population activity was recorded during the task, using the Cerebus data-acquisition system. Spatio-temporal trains of action potentials were obtained from the original neuronal population signals. Results During the Y-maze working memory task, some neurons showed significantly in- creased firing rates and evident neuronal ensemble activity. Moreover, the anticipatory activity was associated with the delayed alternate choice of the upcoming movement. In correct trials, the averaged pre-event firing rate （10.86 ± 1.82 spikes/ bin） was higher than the post-event rate （8.17 ± 1.15 spikes/bin） （P 〈0.05）. However, in incorrect trials, the rates did not differ. Conclusion The results indicate that the anticipatory activity of a neuronal ensemble in the prefrontal cortex may play a role in encoding working memory events.
文摘BACKGROUND In intertrochanteric fractures,the positive medial cortex support reduction is considered to provide a non-anatomical buttress that helps in controlled collapse.AIM To analyze the concept of medial cortical reduction(MCR)and its clinical and radiological association in geriatric intertrochanteric femur fractures.METHODS Geriatric patients who presented with AO/OTA 31A1 and 31A2 femur fractures and treated with proximal femoral nailing between July 2021 and June 2023 were include in this prospective cohort study.Based on the degree of MCR,they were divided into positive,neutral,or negative MCR groups.The demographic baseline characteristics,postoperative radiographic femoral neck-shaft angle and neck length were analyzed at 6,12 and 24 weeks post-surgery.Functional outcomes such as modified Harris Hip Score(HHS)and time to full-weight bearing were also analyzed.RESULTS 47 patients(Male:Famale 35:12)with mean age of 65.8±4.2 years were included in this study.Twenty-two cases had neutral support,nine had negative support,and sixteen had positive support in the medial cortex postoperatively.Baseline characteristics of the three groups were comparable.No significant differences were found in the femur neck length and femur neck-shaft angle changes post-surgery between the groups.The modified HHS was not found to be significant between the groups(P=0.883)as that of the time to full weight bearing(P=0.789).CONCLUSION The type of reduction achieved based on medial cortical alignment does not affect the femur neck length shortening or varus collapse.Future randomized controlled trials are needed to validate the findings noted in the study.
基金supported by Pamukkale University(Scientific Research Projects Coordination Unit)
文摘The aim of this study was to investigate proton magnetic resonance spectroscopy metabolite values in the medial prefrontal cortex of individuals with euthymic bipolar disorder. The subjects consisted of 15 patients with euthymic bipolar disorder type I and 15 healthy controls. We performed proton magnetic resonance spectroscopy of the bilateral medial prefrontal cortex and measured levels of N-acetyl aspartate, choline and creatine. Levels of these three metabolites in the medial prefrontal cortex were found to be lower in patients with bipolar disorder compared with healthy controls. A positive correlation was found between illness duration and choline levels in the right medial prefrontal cortex. Our study suggests that during the euthymic period, there are abnormalities in cellular energy and membrane phospholipid metabolism in the medial prefrontal cortex, and that this may impair neuronal activity and integrity.
基金supported by National Natural Science Foundation of China grants (31625013 and 91732302)a Shanghai Brain-Intelligence Project of the Science and Technology Commission of Shanghai Municipality(16JC1420501)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDBS01060200)Program of Shanghai Academic Research Leaderthe Open Large Infrastructure Research of Chinese Academy of Sciencesthe Shanghai Municipal Science and Technology Major Project (2018SHZDZX05)National Natural Science Foundation of China (81801354)。
文摘Methyl-CpG binding protein 2(MeCP2) is a basic nuclear protein involved in the regulation of gene expression and microRNA processing.Duplication of MECP2-containing genomic segments causes MECP2 duplication syndrome,a severe neurodevelopmental disorder characterized by intellectual disability,motor dysfunction,heightened anxiety,epilepsy,autistic phenotypes,and early death.Reversal of the abnormal phenotypes in adult mice with MECP2 duplication(MECP2-TG) by normalizing the MeCP2 levels across the whole brain has been demonstrated.However,whether different brain areas or neural circuits contribute to different aspects of the behavioral deficits is still unknown.Here,we found that MECP2-TG mice showed a significant social recognition deficit,and were prone to display aversive-like behaviors,including heightened anxiety-like behaviors and a fear generalization phenotype.In addition,reduced locomotor activity was observed in MECP2-TG mice.However,appetitive behaviors and learning and memory were comparable in MECP2-TG and wild-type mice.Functional magnetic resonance imaging illustrated that the differences between MECP2-TG and wild-type mice were mainly concentrated in brain areas regulating emotion and social behaviors.We used the CRISPR-Cas9 method to restore normal MeCP2 levels in the medial prefrontal cortex(mPFC) and bed nuclei of the stria terminalis(BST) of adult MECP2-TG mice,and found that normalization of MeCP2 levels in the mPFC but not in the BST reversed the social recognition deficit.These data indicate that the mPFC is responsible for the social recognition deficit in the transgenic mice,and provide new insight into potential therapies for MECP2 duplication syndrome.
基金CAMS Innovation Fund for Medical Sciences(CIFMS),Grant/Award Number:2021-I2M-1-034National Natural Science Foundation of China,Grant/Award Number:31970510Young Elite Scientist Sponsorship Program by CAST,Grant/Award Number:2019QNRC001。
文摘Object:Early-life neglect has irreversible emotional effects on the central nervous system.In this work,we aimed to elucidate distinct functional neural changes in me-dial prefrontal cortex(mPFC)of model rats.Methods:Maternal separation with early weaning was used as a rat model of early-life neglect.The excitation of glutamatergic and GABAergic neurons in rat mPFC was recorded and analyzed by whole-cell patch clamp.Results:Glutamatergic and GABAergic neurons of mPFC were distinguished by typi-cal electrophysiological properties.The excitation of mPFC glutamatergic neurons was significantly increased in male groups,while the excitation of mPFC GABAergic neurons was significant in both female and male groups,but mainly in terms of rest membrane potential and amplitude,respectively.Conclusions:Glutamatergic and GABAergic neurons in medial prefrontal cortex showed different excitability changes in a rat model of early-life neglect,which can contribute to distinct mechanisms for emotional and cognitive manifestations.
基金supported by the National Natural Science Foundation of ChinaNos.32170950(to LY),31970915(to LY),31871170(to CL)+4 种基金the Natural Science Foundation of Guangdong Province for Major Cultivation ProjectNo.2018B030336001(to LY)the Natural Science Foundation of Guangdong Province,Nos.2021A1515010804(to CL),2023A1515010899(to CL)the Guangdong Grant‘Key Technologies for Treatment of Brain Disorders’No.2018B030332001(to CL)。
文摘Tibetan singing bowls emit low-frequency sounds and produce perceptible harmonic tones and vibrations through manual tapping.The sounds the singing bowls produce have been shown to enhance relaxation and reduce anxiety.However,the underlying mechanism remains unclear.In this study,we used chronic restraint stress or sleep deprivation to establish mouse models of anxiety that exhibit anxiety-like behaviors.We then supplied treatment with singing bowls in a bottomless cage placed on the top of a cushion.We found that unlike in humans,the combination of harmonic tones and vibrations did not improve anxietylike behaviors in mice,while individual vibration components did.Additionally,the vibration of singing bowls increased the level of N-methyl-D-aspartate receptor 1 in the somatosensory cortex and prefrontal cortex of the mice,decreased the level ofγ-aminobutyric acid A(GABA)receptorα1 subtype,reduced the level of CaMKII in the prefrontal cortex,and increased the number of GABAergic interneurons.At the same time,electrophysiological tests showed that the vibration of singing bowls significantly reduced the abnormal low-frequency gamma oscillation peak frequency in the medial prefrontal cortex caused by stress restraint pressure and sleep deprivation.Results from this study indicate that the vibration of singing bowls can alleviate anxiety-like behaviors by reducing abnormal molecular and electrophysiological events in somatosensory and medial prefrontal cortex.
基金This study protocol was reviewed and approved by Animal Care and Use Committee of Nanyang Normal University(approved number:20201202005).
文摘Social hierarchy greatly influences behavior and health.Both human and animal studies have signaled the medial prefrontal cortex(mPFC)as specifically related to social hierarchy.Dopamine D1 receptors(D1Rs)and D2 receptors(D2Rs)are abundantly expressed in the mPFC,modulat-ing its functions.However,it is unclear how DR-expressing neurons in the mPFC regulate social hierarchy.Here,using a confrontation tube test,we found that most adult C57BL/6J male mice could establish a linear social rank after 1 week of cohabitation.Lower rank individuals showed social anxiety together with decreased serum testosterone levels.D2R expression was significantly downregulated in the dorsal part of mPFC(dmPFC)in lower rank individuals,whereas D1R expression showed no significant difference among the rank groups in the whole mPFC.Virus knockdown of D2Rs in the dmPFC led to mice being particularly prone to lose the contests in the confrontation tube test.Finally,simultaneous D2R activation in the subordinates and D2R inhibition in the dominants in a pair switched their dominant-subordinate relationship.The above results indicate that D2Rs in the dmPFC play an important role in social dominance.Our findings provide novel insights into the divergent func-tions of prefrontal D1Rs and D2Rs in social dominance,which may contribute to ameliorating social dysfunctions along with abnormal social hierarchy.
基金Project supported by the Natural Science Foundation of Zhejiang Province(No.LY17H180007)the Scientific Research Fund of Zhejiang Education Department(No.Y201431735)the Hangzhou Science and Technology Commission Foundation(No.20170533B06),China
文摘Medial orbitofrontal cortex （mOFC） abnormalities have been observed in various anxiety disorders. However, the relationship between mOFC activity and anxiety among the healthy population has not been fully examined. Here, we conducted a resting state functional magnetic resonance imaging （R-fMRI） study with 56 healthy male adults from the Nathan Kline Institute/Rockland Sample （NKI-RS） to examine the relationship between the fractional amplitude of low-frequency fluctuation （fALFF） signals and trait anxiety across the whole brain. A Louvain method for module detection based on graph theory was further employed in the automated functional subdivision to explore subregional correlates of trait anxiety. The results showed that trait anxiety was related to fALFF in the mOFC. Additionally, the resting-state functional connectivity （RSFC） between the right subregions of the mOFC and the precuneus was correlated with trait anxiety. These findings provided evidence about the involvement of the mOFC in anxiety processing among the healthy population.
基金supported by the Key Research Project of Science and Technology of Henan Province of China,No.14B180007(to LLF)the Development Project of Science and Technology of Luoyang Municipality of China,No.1401087A-5(to LLF)
文摘The dysfunction of the medial prefrontal cortex is associated with affective disorders and non-motor features in Parkinson’s disease.However,the exact role of the mediodorsal thalamic nucleus in the function of the prefrontal cortex remains unclear.To study the possible effects of the mediodorsal thalamic nucleus on the neurological function of the medial prefrontal cortex,a model of Parkinson’s disease was established by injecting 8μg 6-hydroxydopamine into the substantia nigra compacta of rats.After 1 or 3 weeks,0.3μg ibotenic acid was injected into the mediodorsal thalamic nucleus of the midbrain.At 3 or 5 weeks after the initial injury,neuronal discharge in medial prefrontal cortex of rat brain was determined electrophysiologically.The numbers of dopamine-positive neurons and tyrosine hydroxylase immunoreactivity in substantia nigra compacta and ventral tegmental area were detected by immunohistochemical staining.Results demonstrated that after injury,the immunoreactivity of dopamine neurons and tyrosine hydroxylase decreased in the substantia nigra compacta and ventral tegmental areas of rats.Compared with normal medial prefrontal cortical neurons,at 3 and 5 weeks after substantia nigra compacta injury,the discharge frequency of pyramidal neurons increased and the discharge pattern of these neurons tended to be a burst-discharge,with an increased discharge interval.The discharge frequency of interneurons decreased and the discharge pattern also tended to be a burst-discharge,but the discharge interval was only higher at 3 weeks.At 3 weeks after the combined lesions,the discharge frequency,discharge pattern and discharge interval were restored to a normal level in pyramidal neurons and interneurons in medial prefrontal cortex.These findings have confirmed that mediodorsal thalamic nucleus is involved in regulating neuronal activities of the medial prefrontal cortex.The changes in the function of the mediodorsal thalamic nucleus may be associated with the abnormal discharge activity of the medial prefrontal cortex neurons after substantia nigra compacta injury.All experimental procedures were approved by the Institutional Animal Care and Use Committee of Xi’an Jiaotong University,China(approval No.XJTULAC2017-067)on August 26,2017.
基金supported by JSPS KAKENHI(24659574,26112003,and 15K14328),and JP 16H06276(AdAMS).
文摘Nicotine addiction is a concern worldwide.Most mechanistic investigations are on nicotine substance dependence properties based on its pharmacological effects.However,no effective therapeutic treatment has been established.Nicotine addiction is reinforced by environments or habits.We demonstrate the neurobiological basis of the behavioural aspect of nicotine addiction.We utilized the conditioned place preference to establish nicotine-associated behavioural preferences(NABP)in rats.Brain-wide neuroimaging analysis revealed that the medial prefrontal cortex(mPFC)was activated and contributed to NABP.Chemogenetic manipulation ofµ-opioid receptor positive(MOR+)neurons in the mPFC or the excitatory outflow to the nucleus accumbens shell(NAcShell)modulated the NABP.Electrophysiological recording confirmed that the MOR+neurons directly regulate the mPFC-NAcShell circuit via GABAA receptors.Thus,the MOR+neurons in the mPFC modulate the formation of behavioural aspects of nicotine addiction via direct excitatory innervation to the NAcShell,which may provide new insight for the development of effective therapeutic strategies.
文摘Introduction: Transcranial Magnetic Stimulation (TMS) is a non-invasive technique for brain stimulation. Repetitive TMS (rTMS) over the medial Prefrontal Cortex (mPFC), Broadman Area 10 (BA10) may stimulate transynaptically perigenual Anterior Cingulate Cortex (pACC, BA 33), insula, amigdala, hypothalamus and connected branches of the Autonomic Nervous System (ANS) involved in stressorevoked cardiovascular reactivity. Stressors are associated with an increase in sympathetic cardiac control, a decrease in parasympathetic control, or both, and, consequently, an increase in systolic/stroke volume, total vascular impedance/resistance and heart rate, a decrease of baroreflex sensitivity, i.e., an increase in blood pressure/arterial tension. Objectives and Aims: The present work aims, using TMS and accordingly to Gianaros modeling, based on functional neuroimaging studies and previous neuroanatomical data from animal models, to probe the connectivity of brain systems involved in stressor-evoked cardiovascular reactivity and to explore TMS potential as a tool for detection and stratification of individual differences concerning this reactivity and hemorreological risk factors correlated with the development of Coronary Heart Disease (CHD). Methods: Both subjects, a 52 years old male and a 40 years old female with previous increased Low Frequency (LF)/High Frequency (HF) Heart Rate Variability (HRV) ratios (respectively, 4.209/3.028) without decompensated cardiorespiratory symptoms, gave informed consent, and ethico-legal issues have been observed. Electroencephalographic (EEG) monitoring has been performed for safety purposes. Immediately after administration, over the mPFC, of 15 pulses of rTMS, during 60 second, with an inductive electrical current, at the stimulating coil, of 85.9 Ampère per μsecond and 66 Ampère per μsecond, respectively, for male and female subjects (a “figure-of-eight” coil and magnetic stimulator MagLite, Dantec/Medtronic, have been used), HRV spectrum analysis (cStress software) has been performed (during 5 minutes, in supine position). Results: In both subjects, LF power, HF power and LF/HF ratio results, before and after rTMS administration, pointed towards sympathetic attenuation and parasympathetic augmentation (respectively, in male/female subject: decreased LF power—65.1 nu/69.3 nu, before rTMS;56.1 nu/41.6 nu, after rTMS;increased HF power—15.5 nu/22.9 nu, before rTMS;30.9 nu/45.5 nu, after rTMS). Conclusions: In this preliminary investigation, the existence of a link between “mind” and heart’s function has been put in evidence, through a reversible “virtual” lesion, of brain systems involved in cardiovascular control, caused by TMS. Repetitive TMS over mPFC decreased brain function involved in stressorevoked cardiovascular reactivity, suggesting the importance of TMS in the management of stress-related cardiovascular disorders.
