Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inh...Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. Moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased complexity and restructuring of neural network structures, as well as the addition of new granule granule cells that aid in olfactory adaptation. Additionally, the manuscript underscores the importance of employing precise methodologies to elucidate the specific roles of adult neurogenesis amidst conflicting data and varying experimental paradigms. Understanding these processes is essential for gaining insights into the complexities of olfactory function and behavior.展开更多
Iron is the most abundant transition metal in the brain and is essential for brain development and neuronal function;however,its abnormal accumulation is also implicated in various neurological disorders.The olfactory...Iron is the most abundant transition metal in the brain and is essential for brain development and neuronal function;however,its abnormal accumulation is also implicated in various neurological disorders.The olfactory bulb(OB),an early target in neurodegenerative diseases,acts as a gateway for environmental toxins and contains diverse neuronal populations with distinct roles.This study explored the cell-specific vulnerability to iron in the OB using a mouse model of intranasal administration of ferric ammonium citrate(FAC).Olfactory function was assessed through olfactory discrimination tests,while iron levels in OB tissues,cerebrospinal fluid(CSF),and serum were quantified using inductively coupled plasma mass spectrometry(ICP-MS),immunohistochemical staining,and iron assays.Transcriptomic changes and immune responses were assessed using RNA sequencing and immune cell infiltration analysis.Results showed that intranasal FAC administration impaired olfactory function,accompanied by iron deposition in the olfactory mucosa and OB,as well as damage to olfactory sensory neurons.Notably,these effects occurred without elevations in CSF or serum iron levels.OB iron accumulation activated multiple immune cells,including microglia and astrocytes,but did not trigger ferroptosis.Spatial transcriptomic sequencing of healthy adult mouse OBs revealed significant cellular heterogeneity,with an abundance of neuroglia and neurons.Among neurons,GABAergic neurons were the most prevalent,followed by glutamatergic and dopaminergic neurons,while cholinergic and serotonergic neurons were sparsely distributed.Under iron-stressed conditions,oligodendrocytes,dopaminergic neurons,and glutamatergic neurons exhibited significant damage,while GABAergic neurons remained unaffected.These findings highlight the selective vulnerability of neuronal and glial populations to iron-induced stress,offering novel insights into the loss of specific cell types in the OB during iron dysregulation.展开更多
Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extract...Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extracts as an antibulbing substance,the amount of which was synchronized with the bulb formation.Since allene oxide synthase inhibitor canceled the antibulbing activity ofα-linolenic acid,it was disclosed that jasmonic acid concerns this regulation.Structure-activity-relationship study revealed that its(3R,7S)stereochemistry is necessary for showing its antibulbing activity.It is concluded that(3R,7S)-jasmonate derived fromα-linolenic acid actually participates in the regulation of bulb formation.展开更多
The olfactory bulb(OB)is the first relay station in the olfactory system and functions as a crucial hub.It can represent odor information precisely and accurately in an ever-changing environment.As the only output neu...The olfactory bulb(OB)is the first relay station in the olfactory system and functions as a crucial hub.It can represent odor information precisely and accurately in an ever-changing environment.As the only output neurons in the OB,mitral/tufted cells encode information such as odor identity and concentration.Recently,the neural strategies and mechanisms underlying odor representation and encoding in the OB have been investigated extensively.Here we review the main progress on this topic.We first review the neurons and circuits involved in odor representation,including the different cell types in the OB and the neural circuits within and beyond the OB.We will then discuss how two different coding strategies—spatial coding and temporal coding—work in the rodent OB.Finally,we discuss potential future directions for this research topic.Overall,this review provides a comprehensive description of our current understanding of how odor information is represented and encoded by mitral/tufted cells in the OB.展开更多
A new natural product (1) together with 26 know compounds were isolated from the Bulbs of Ornithogalum caudatum. Their structures were established on the basis of spectral analyses as n-butyl pyroglutamate (1), nonade...A new natural product (1) together with 26 know compounds were isolated from the Bulbs of Ornithogalum caudatum. Their structures were established on the basis of spectral analyses as n-butyl pyroglutamate (1), nonadecyl alcohol(2), eicosanol(3), behenic acid(4), b-sitosterol(5), stigmasterol(6), glycerol 1-monocerotate(7), pyrocatechol(8), p-ethoxybenzoic acid(9), p-coumarinic acid(10), protocatechuric acid(11), ursolic acid(12), betulinic acid(13), fumaric acid(14), succinic acid(15), uracil(16), xanthine(17), quercetin(18), kaempferol (19), isorham-netin(20), adenosine(21), daucosterol(22), stigmasterol 3-O-b-D-glucopyranoside(23), quercetin 3-O-b-D-glucopyra-noside(24), kaempferol 3-O-b-D-glucopyranoside(25), rutin(26), and kaempferol 3-O-b-rutinoside(27). All of them, except compound 5, were isolated from this plant for the first time.展开更多
With different parts of bulb scale as explants, the proliferation method of Guizhou Lilium brownii were studied with 3% sodium hypochlorite and MS medium with different concentrations of hormones. The results show tha...With different parts of bulb scale as explants, the proliferation method of Guizhou Lilium brownii were studied with 3% sodium hypochlorite and MS medium with different concentrations of hormones. The results show that it is feasible to disinfect the bulbs of Lilium brownii with 3% sodium hypoehlorite, moreover, the sodium hypochlorite is very cheap and harmless to researchers, experimental materials and environment. MS ＋ NAA 0.3 mg/L ＋ 6-BA 1.5 mg/L is optimum for the induction of bulbs and, the basal part of Lilium brownie is the optimum explants. After culture for 25 d on the same medium, the tube bulbs could be obtained with the characteristics of high propagation coefficient, strong and new roots. The survival rate is over 90% for transplantation of tube bulbs with diameter between 1-2cm. The method developed in the present study can proliferate abundant Lilium brownii seedling in short time.展开更多
To gain insight into the function of AOB and MOB during different social interaction and in different vole species,the behaviors and neural activation of the olfactory bulbs in social interactions of mandarin voles Mi...To gain insight into the function of AOB and MOB during different social interaction and in different vole species,the behaviors and neural activation of the olfactory bulbs in social interactions of mandarin voles Microtus mandarinus and reed voles Microtus fortis were compared in the present research.Mandarin voles spent significantly more time attacking and sniffing their opponents and sniffing sawdust than reed voles.During same sex encounters,mandarin voles attacked their opponents for a significantly longer time and sniffed its opponent for shorter time compared with male-female interactions.However,no significant behavioral differences were found during encounters of two individual reed voles,regardless of gender composition of the pair.Using c-Fos as an indicator of neural activation,we observed that neural activation was significantly higher in almost all sub-regions of the main olfactory bulb(MOB)and the accessory olfactory bulb(AOB)of mandarin voles compared with reed voles.Numbers of c-Fos-ir neurons in almost all sub-regions of the AOB and the MOB during male-female interactions were also higher than those in interactions of the same sex.Anterior-posterior ratios of Fos-ir neurons in the AOBM(AOBMR)and the AOBG(AOBGR)in male-female interaction were significantly higher than those in interaction of the same sex.The AOBMR of male mandarin voles and reed voles were larger than those of females in male-female interactions.Behavioral patterns are consistent with cellular activity patterns.Consistent level of neural activation in MOB and AOB suggests important roles of both the main olfactory bulb and the accessory olfactory bulb in social interaction in two species.展开更多
In order to investigate the neuroendocrine mechanism of the mating behavior in the adult male mandarin voles Microtus mandarinus,the radioimmunoassay(RIA)and immunohistochemistry methods were used to investigate the d...In order to investigate the neuroendocrine mechanism of the mating behavior in the adult male mandarin voles Microtus mandarinus,the radioimmunoassay(RIA)and immunohistochemistry methods were used to investigate the differences in plasma testosterone(T)concentrations and distribution of T immunoreactive neurons(T-IRs),androgen receptor immunoreactive neurons(AR-IRs)and Fos protein immunoreactive neurons(Fos-IRs)in the accessory olfactory bulb(AOB)and the main olfactory bulb(MOB)following exposure to clean hard-wood shavings(control group),soiled bedding(exposure group)or contact with an estrous female(mating group).Results showed that plasma T concentration was significantly higher in the mating group than that in the exposure group,and both the mating group and the exposure group displayed significantly higher plasma T concentration than the control group.T-IRs,AR-IRs and Fos-IRs were investigated with the immunohistochemistry method in granule cell(GC)and mitral cell(MC)of the MOB and the AOB in the three groups.There were significantly more T-IRs,AR-IRs and Fos-IRs in MC and GC of the AOB in the mating group than that in the exposure group or the control group.T-IRs,AR-IRs and Fos-IRs did not show significant differences between the exposure group and the control group.Furthermore,obvious differences in MC and GC of the MOB were not found among the three groups.The results confirm that both changes of T and AR in the AOB might be underlying mating behavior in the adult male mandarin voles.展开更多
Objective] The aim of this study was to investigate the electrophysiological characteristics of spontaneous electrical activities of olfactory bulb in Bufo gargarizans during postembryonic development. [Method] Microe...Objective] The aim of this study was to investigate the electrophysiological characteristics of spontaneous electrical activities of olfactory bulb in Bufo gargarizans during postembryonic development. [Method] Microelectrode technique was used to record extracellular spontaneous electrical activities of olfactory bulb in B. gar-garizans. [Result] Along with the development of olfactory bulb, the discharge types increased gradual y. Single spontaneous firing enhanced gradual y and it reached the maximum in the metamorphosis phase. The intensity of consecutive single sponta-neous firing changed slightly at the middle of post-embryonic development, but it was stil higher than in the early phase and the adult phase. Consecutive burst spontaneous firing frequency went down over time. [Conclusion] Along with the de-velopment of olfactory bulb, the neuronal excitability increases step by step and the neuronal electrical activities diversify gradualy.展开更多
The purpose of this article is to detect sex and age difference in the structure of the olfactory bulb in dogs by histological methods. The thickness of the olfactory bulbs layers and its main cells were analyzed comp...The purpose of this article is to detect sex and age difference in the structure of the olfactory bulb in dogs by histological methods. The thickness of the olfactory bulbs layers and its main cells were analyzed comparatively with the methods of HE-staining and statistics, through which we studied the development course of dogs＇ olfactory bulb and the structural differences which affect the olfaction in both males and females. The results showed that between both male and female juveniles and adult males and females, the difference in thickness of each layer is not significant. But the difference in quantity of mitral cells between adult males and females was significant. Meanwhile, the structure of every layer in juvenile dogs was apparent while the volume and the weight of adult dogs＇ olfactory bulb and each layer＇s width increased significantly. On the other hand, the density of each layer＇s cells decreased apparently. Our results demonstrated that the olfactory bulb developed with age, and the apparent differences in morphology and quantity of mitral cells between males and females may be one of the reasons leading to the sexual variations of olfactory sensitivity.展开更多
[Objective] The purpose of this study is to investigate the effects of differ- ent phytohormones on the adventitious bud differentiation of oriental lily. [Method] The bulb scales of the test-tube plantlets of Tiber, ...[Objective] The purpose of this study is to investigate the effects of differ- ent phytohormones on the adventitious bud differentiation of oriental lily. [Method] The bulb scales of the test-tube plantlets of Tiber, Rodina and Constanta were cul- tured in media supplemented with different cytokinin and auxin at different concen- tration, and then the adventitious buds in each treatment were calculated. [Result] Cytokinins had different influence on the adventitious bud differentiation of the three oriental lily cultivars. Among them, 6-BA had the best effect to induce the adventi- tious bud differentiation from bulb scales of Tiber and Rodina, but there was some difference in the optimal concentration. KT had the best effect to induce the adven- titious bud differentiation of Constanta. The auxins had little influence on the quality of the adventitious bud of the three oriental lily cultivars, but caused some difference in differentiation coefficients. [Conclusion] The most suitable media for the adventi- tious bud differentiation from bulb scales in vitro of Tiber, Rodina and Constanta were MS＋0.2 mg/L 6-BA＋0.2 mg/L 2,4-D, MS＋I.0 mg/L 6-BA＋0.2 mg/L IAA, MS＋ 1.0 mg/L KT＋0.5 mg/L 2,4-D, respectively.展开更多
An equation model for calculating the adiabatic temperature of the wet-bulb thermometer has been obtained empirical fit through a meteorological database, specificly a trough relative humidity and air temperature. A c...An equation model for calculating the adiabatic temperature of the wet-bulb thermometer has been obtained empirical fit through a meteorological database, specificly a trough relative humidity and air temperature. A comparison of the results of calculations with the use of this equation and from meteorological database was made. The model deducted of the comparison is valid for a dry bulb temperature range of 3°C to 35°C and for relative humidity percentage in a range of 7% to 97%. Normalized errors are less than 5.5%. It means a maximum variation of 0.55°C from data. However, this variation from error represents only 3.6% of the data sample. The equation model was satisfactory.展开更多
The dynamics of the growth of roots and leaves of the Allium cepa L. after the mechanical removal of a part of the root system or the bulb was studied. It was shown that, after surgical interference, the potency for o...The dynamics of the growth of roots and leaves of the Allium cepa L. after the mechanical removal of a part of the root system or the bulb was studied. It was shown that, after surgical interference, the potency for organogenesis is retained, although it is weakened.展开更多
<strong>Objectives:</strong> Pulsatile tinnitus involves a wide spectrum of etiologies. The etiologies include normal vascular variants, temporal bone tumor, acquired vascular lesions and chronic middle ea...<strong>Objectives:</strong> Pulsatile tinnitus involves a wide spectrum of etiologies. The etiologies include normal vascular variants, temporal bone tumor, acquired vascular lesions and chronic middle ear inflammatory diseases. Jugular bulb diverticulum is a rare cause of pulsatile tinnitus. We report one case of jugular diverticulum presenting with pulsatile tinnitus and its surgical management and outcome. <strong>Case Report:</strong> A 36-year-old woman with a history of uterine myoma and chronic anemia presented with right pulsatile tinnitus that was worsening in recent one month. Neurological exam was normal. ENT evaluation revealed no abnormalities via otoscopy and physical examination. The CT scan revealed right dominant jugular bulb with diverticulum projecting to posterior ear canal wall. We performed jugular bulb diverticulum resurfacing with temporalis fascia, Surgicel<sup>®</sup> and Gelfoam<sup>®</sup>, and bone wax via transmastoid approach. The symptom improved postoperative immediately. No major complications were noted during outpatient clinic follow-up. <strong>Conclusion:</strong> Transmastoid resurfacing of jugular bulb diverticulum is an effective management of pulsatile tinnitus from this kind vascular anomaly.展开更多
The main active components extracted from Panax notoginseng are total saponins. They have been shown to inhibit platelet aggregation, increase cerebral blood flow, improve neurological behavior, decrease infarct volum...The main active components extracted from Panax notoginseng are total saponins. They have been shown to inhibit platelet aggregation, increase cerebral blood flow, improve neurological behavior, decrease infarct volume and promote proliferation and differentiation of neural stem cells in the hippocampus and lateral ventricles. However, there is a lack of studies on whether total saponins of Panax notoginsertg have potential benefits on immature neuroblasts in the olfactory bulb following ischemia and reperfusion. This study established a rat model of global cerebral ischemia and reperfusion using four-vessel occlusion. Rats were administered total sa- ponins of Panax notoginseng at 75 mg/kg intraperitoneally 30 minutes after ischemia then once a day, for either 7 or 14 days. Total saponins of Panax notoginseng enhanced the number of dou- blecortin （DCX）＋ neural progenitor ceils and increased co-localization of DCX with neuronal nuclei and phosphorylated cAMP response element-binding/DCX＋ neural progenitor cells in the olfactory bulb at 7 and 14 days post ischemia. These findings indicate that following global brain ischemia/reperfusion, total saponins of Panax notoginseng promote differentiation of DCX＋ cells expressing immature neuroblasts in the olfactory bulb and the underlying mechanism is related to the activation of the signaling pathway of cyclic adenosine monophosphate response element binding protein.展开更多
Sensory processing is strongly modulated by different brain and behavioral states,and this is based on the top-down modulation.In the olfactory system,local neural circuits in the olfactory bulb(OB)are innervated by c...Sensory processing is strongly modulated by different brain and behavioral states,and this is based on the top-down modulation.In the olfactory system,local neural circuits in the olfactory bulb(OB)are innervated by centrifugal afferents in order to regulate the processing of olfactory information in the OB under different behavioral states.The purpose of the present study was to explore the organization of neural networks in olfactory-related cortices and modulatory nuclei that give rise to direct and indirect innervations to the glomerular layer(GL)of the OB at the whole-brain scale.Injection of different recombinant attenuated neurotropic viruses into the GL showed that it received direct inputs from each layer in the OB,centrifugal inputs from the ipsilateralanterior olfactory nucleus(AON),anterior piriform cortex(Pir),and horizontal limb of diagonal band of Broca(HDB),and various indirect inputs from bilateral cortical neurons in the AON,Pir,amygdala,entorhinal cortex,hippocampus,HDB,dorsal raphe,median raphe and locus coeruleus.These results provide a circuitry basis that will help further understand the mechanism by which olfactory informationprocessing in the OB is regulated.展开更多
Hyperhomocysteinemia has been shown to be associated with neurodegenerative diseases; however, lesions or histological changes and mechanisms underlying homocysteine-induced injury in olfactory bulb neurons remain unc...Hyperhomocysteinemia has been shown to be associated with neurodegenerative diseases; however, lesions or histological changes and mechanisms underlying homocysteine-induced injury in olfactory bulb neurons remain unclear. In this study, hyperhomocysteinemia was induced in apolipoprotein E-deficient mice with 1.7% methionine. Pathological changes in the olfactory bulb were observed through hematoxylin-eosin and Pischingert staining. Cell apoptosis in the olfactory bulb was determined through terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） staining. Transmission electron microscopy revealed an abnormal ultrastructure of neurons. Furthermore, immunoreactivity and expression of the hairy enhancer of the split 1 （Hesl） and Hess were measured using immunohistochemistry, immunofluorescence, and western blot assay. Our results revealed no significant structural abnormality in the ol- factory bulb of hyperhomocysteinemic mice. However, the number of TUNEL-positive cells increased in the olfactory bulb, lipofuscin and vacuolization were visible in mitochondria, and the expression of Hes1 and Hes5 decreased. These findings confirm that hyperhomocyste- inemia induces injury in olfactory bulb neurons by downregulating Hes1 and Hes5 expression.展开更多
With the increasing demand for the clean sustainable power, the turbine design urgently turns to increase the capability significantly toward higher head for generating larger power. Currently, there are many studies ...With the increasing demand for the clean sustainable power, the turbine design urgently turns to increase the capability significantly toward higher head for generating larger power. Currently, there are many studies in the field of the bulb turbine with single-stage runner, though reports about counter-rotating tandem-runner are rare. However, the further high-head application with the single-stage runner is very difficult to achieve due to the limit of the specific speed. In this paper, a new bulb turbine with the tandem-runner is designed in order to substantially increase the applicable limit toward higher head with larger power. A half of the net head is absorbed by the frontal runner which can generate output power, while the remaining half is absorbed by the rear runner. To generate the Euler energy required for the rear runner, the frontal runner has the counter-rotation against the rear runner so that the counter-rotating tandem-runner can meet the purpose of double head and power under the same size as the conventional bulb turbine. Supply and demand of Euler energy between the two runners are thoroughly optimized through the detailed flow analysis, in order to secure the stable operation. As a result, the interference of Euler energies between the outflow from the frontal runner and the inflow to the rear runner is confirmed to be very small on the counter-rotating interface between the two runners. The prediction method of on-cam performance between the two adjustable runners is also developed numerically, which provides optimal flow between the two runners. This research provides a theoretical basis for the optimal design and operation of the counter-rotating tandem-runner bulb turbines.展开更多
Microelectrode technique was used to record the spontaneous electrical activities of the neurons in olfactory bulb of the Bufo bufo gargarizans, both in hibernation and after hibemation. This study investigated the el...Microelectrode technique was used to record the spontaneous electrical activities of the neurons in olfactory bulb of the Bufo bufo gargarizans, both in hibernation and after hibemation. This study investigated the electrophysiological characteristics of amphibian olfactory bulb in the period of hibernation and after hibernation and its effects on the start of hibernation and spontaneous awakening. The research showed four forms of spontaneous firings： single spontaneous firing, burst spontaneous firing, irregular spontaneous firing and consecutive single spontaneous firing. The single spontaneous firing includes slow depolarized spontaneous firing and fast depolarized spontaneous firing, and the slow depolarized spontaneous firing occurs only during the hibernation period. In hibernation, the low amplitude and low frequency firing with a longer duration may be relevant to maintaining the tonicity of the central nervous system in toads that are in hibernation, and this kind of firing may also provide an excited basis for their arousal from hibernation. After hibernation, the amplitude and frequency of firing increase, but the firing duration gets shorter. This form of short-term firing, which may be a phenomenon of sensory neurons fast adapting, is one of the neuronal mechanisms for the arousal of hibernating animals.展开更多
文摘Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. Moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased complexity and restructuring of neural network structures, as well as the addition of new granule granule cells that aid in olfactory adaptation. Additionally, the manuscript underscores the importance of employing precise methodologies to elucidate the specific roles of adult neurogenesis amidst conflicting data and varying experimental paradigms. Understanding these processes is essential for gaining insights into the complexities of olfactory function and behavior.
基金supported by the National Natural Science Foundation of China (32471188,32170984,82301787)。
文摘Iron is the most abundant transition metal in the brain and is essential for brain development and neuronal function;however,its abnormal accumulation is also implicated in various neurological disorders.The olfactory bulb(OB),an early target in neurodegenerative diseases,acts as a gateway for environmental toxins and contains diverse neuronal populations with distinct roles.This study explored the cell-specific vulnerability to iron in the OB using a mouse model of intranasal administration of ferric ammonium citrate(FAC).Olfactory function was assessed through olfactory discrimination tests,while iron levels in OB tissues,cerebrospinal fluid(CSF),and serum were quantified using inductively coupled plasma mass spectrometry(ICP-MS),immunohistochemical staining,and iron assays.Transcriptomic changes and immune responses were assessed using RNA sequencing and immune cell infiltration analysis.Results showed that intranasal FAC administration impaired olfactory function,accompanied by iron deposition in the olfactory mucosa and OB,as well as damage to olfactory sensory neurons.Notably,these effects occurred without elevations in CSF or serum iron levels.OB iron accumulation activated multiple immune cells,including microglia and astrocytes,but did not trigger ferroptosis.Spatial transcriptomic sequencing of healthy adult mouse OBs revealed significant cellular heterogeneity,with an abundance of neuroglia and neurons.Among neurons,GABAergic neurons were the most prevalent,followed by glutamatergic and dopaminergic neurons,while cholinergic and serotonergic neurons were sparsely distributed.Under iron-stressed conditions,oligodendrocytes,dopaminergic neurons,and glutamatergic neurons exhibited significant damage,while GABAergic neurons remained unaffected.These findings highlight the selective vulnerability of neuronal and glial populations to iron-induced stress,offering novel insights into the loss of specific cell types in the OB during iron dysregulation.
基金Supported by the Naito FoundationGrant-in-Aid for Scientific Research (22K05448)from Japan Society for the Promotion of Science.
文摘Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extracts as an antibulbing substance,the amount of which was synchronized with the bulb formation.Since allene oxide synthase inhibitor canceled the antibulbing activity ofα-linolenic acid,it was disclosed that jasmonic acid concerns this regulation.Structure-activity-relationship study revealed that its(3R,7S)stereochemistry is necessary for showing its antibulbing activity.It is concluded that(3R,7S)-jasmonate derived fromα-linolenic acid actually participates in the regulation of bulb formation.
基金supported by the National Natural Science Foundation of China(Nos.32271055 and 32070995)the Jiangsu Province Innovative and Entrepreneurial Team Program,and the Guangdong Medical University(No.GDMUB2022048),China.
文摘The olfactory bulb(OB)is the first relay station in the olfactory system and functions as a crucial hub.It can represent odor information precisely and accurately in an ever-changing environment.As the only output neurons in the OB,mitral/tufted cells encode information such as odor identity and concentration.Recently,the neural strategies and mechanisms underlying odor representation and encoding in the OB have been investigated extensively.Here we review the main progress on this topic.We first review the neurons and circuits involved in odor representation,including the different cell types in the OB and the neural circuits within and beyond the OB.We will then discuss how two different coding strategies—spatial coding and temporal coding—work in the rodent OB.Finally,we discuss potential future directions for this research topic.Overall,this review provides a comprehensive description of our current understanding of how odor information is represented and encoded by mitral/tufted cells in the OB.
基金This work was supported by the Ministry of Science and Technology of China (96-901-05-266).
文摘A new natural product (1) together with 26 know compounds were isolated from the Bulbs of Ornithogalum caudatum. Their structures were established on the basis of spectral analyses as n-butyl pyroglutamate (1), nonadecyl alcohol(2), eicosanol(3), behenic acid(4), b-sitosterol(5), stigmasterol(6), glycerol 1-monocerotate(7), pyrocatechol(8), p-ethoxybenzoic acid(9), p-coumarinic acid(10), protocatechuric acid(11), ursolic acid(12), betulinic acid(13), fumaric acid(14), succinic acid(15), uracil(16), xanthine(17), quercetin(18), kaempferol (19), isorham-netin(20), adenosine(21), daucosterol(22), stigmasterol 3-O-b-D-glucopyranoside(23), quercetin 3-O-b-D-glucopyra-noside(24), kaempferol 3-O-b-D-glucopyranoside(25), rutin(26), and kaempferol 3-O-b-rutinoside(27). All of them, except compound 5, were isolated from this plant for the first time.
基金Supported by the Nomarch Funds for Excellent Science and Technology Teachers of Guizhou Province(S2004-17)the Special Foundation for Im-proving Scientific Research Condition of Guizhou Province(Q2005-4)the Doctor Startup of Guiyang Medical College(C2005-6)~~
文摘With different parts of bulb scale as explants, the proliferation method of Guizhou Lilium brownii were studied with 3% sodium hypochlorite and MS medium with different concentrations of hormones. The results show that it is feasible to disinfect the bulbs of Lilium brownii with 3% sodium hypoehlorite, moreover, the sodium hypochlorite is very cheap and harmless to researchers, experimental materials and environment. MS ＋ NAA 0.3 mg/L ＋ 6-BA 1.5 mg/L is optimum for the induction of bulbs and, the basal part of Lilium brownie is the optimum explants. After culture for 25 d on the same medium, the tube bulbs could be obtained with the characteristics of high propagation coefficient, strong and new roots. The survival rate is over 90% for transplantation of tube bulbs with diameter between 1-2cm. The method developed in the present study can proliferate abundant Lilium brownii seedling in short time.
基金supported by National Natural Science Foundation of China(No.30670273No.30200026)Ministry of Education Key Project of Peoples Republic of China(20060718)
文摘To gain insight into the function of AOB and MOB during different social interaction and in different vole species,the behaviors and neural activation of the olfactory bulbs in social interactions of mandarin voles Microtus mandarinus and reed voles Microtus fortis were compared in the present research.Mandarin voles spent significantly more time attacking and sniffing their opponents and sniffing sawdust than reed voles.During same sex encounters,mandarin voles attacked their opponents for a significantly longer time and sniffed its opponent for shorter time compared with male-female interactions.However,no significant behavioral differences were found during encounters of two individual reed voles,regardless of gender composition of the pair.Using c-Fos as an indicator of neural activation,we observed that neural activation was significantly higher in almost all sub-regions of the main olfactory bulb(MOB)and the accessory olfactory bulb(AOB)of mandarin voles compared with reed voles.Numbers of c-Fos-ir neurons in almost all sub-regions of the AOB and the MOB during male-female interactions were also higher than those in interactions of the same sex.Anterior-posterior ratios of Fos-ir neurons in the AOBM(AOBMR)and the AOBG(AOBGR)in male-female interaction were significantly higher than those in interaction of the same sex.The AOBMR of male mandarin voles and reed voles were larger than those of females in male-female interactions.Behavioral patterns are consistent with cellular activity patterns.Consistent level of neural activation in MOB and AOB suggests important roles of both the main olfactory bulb and the accessory olfactory bulb in social interaction in two species.
基金funded by theNatural Science Foundation of China(30670273)Natural Science Foundation of ShaanXi(2008C269)+1 种基金Science and Technology Plan Project of Xi'an Burea of Science and Technology(YF07194)Special Science Research Fund for Xi'an University of Arts and Science(KY200520)
文摘In order to investigate the neuroendocrine mechanism of the mating behavior in the adult male mandarin voles Microtus mandarinus,the radioimmunoassay(RIA)and immunohistochemistry methods were used to investigate the differences in plasma testosterone(T)concentrations and distribution of T immunoreactive neurons(T-IRs),androgen receptor immunoreactive neurons(AR-IRs)and Fos protein immunoreactive neurons(Fos-IRs)in the accessory olfactory bulb(AOB)and the main olfactory bulb(MOB)following exposure to clean hard-wood shavings(control group),soiled bedding(exposure group)or contact with an estrous female(mating group).Results showed that plasma T concentration was significantly higher in the mating group than that in the exposure group,and both the mating group and the exposure group displayed significantly higher plasma T concentration than the control group.T-IRs,AR-IRs and Fos-IRs were investigated with the immunohistochemistry method in granule cell(GC)and mitral cell(MC)of the MOB and the AOB in the three groups.There were significantly more T-IRs,AR-IRs and Fos-IRs in MC and GC of the AOB in the mating group than that in the exposure group or the control group.T-IRs,AR-IRs and Fos-IRs did not show significant differences between the exposure group and the control group.Furthermore,obvious differences in MC and GC of the MOB were not found among the three groups.The results confirm that both changes of T and AR in the AOB might be underlying mating behavior in the adult male mandarin voles.
基金Supported by grants from the Liaoning Provincial Department of Education(2011196)the Experimental Center Director Fund of Shenyang Normal University(sy201003)~~
文摘Objective] The aim of this study was to investigate the electrophysiological characteristics of spontaneous electrical activities of olfactory bulb in Bufo gargarizans during postembryonic development. [Method] Microelectrode technique was used to record extracellular spontaneous electrical activities of olfactory bulb in B. gar-garizans. [Result] Along with the development of olfactory bulb, the discharge types increased gradual y. Single spontaneous firing enhanced gradual y and it reached the maximum in the metamorphosis phase. The intensity of consecutive single sponta-neous firing changed slightly at the middle of post-embryonic development, but it was stil higher than in the early phase and the adult phase. Consecutive burst spontaneous firing frequency went down over time. [Conclusion] Along with the de-velopment of olfactory bulb, the neuronal excitability increases step by step and the neuronal electrical activities diversify gradualy.
基金National Natural Science Foundation of China (30370218)Shan-dong Science Fund for Distinguished Young Scholars(2005BS02005)Science Foundation for Excellent Scholars of Ministry of Education of China (NCET-07-0507)
文摘The purpose of this article is to detect sex and age difference in the structure of the olfactory bulb in dogs by histological methods. The thickness of the olfactory bulbs layers and its main cells were analyzed comparatively with the methods of HE-staining and statistics, through which we studied the development course of dogs＇ olfactory bulb and the structural differences which affect the olfaction in both males and females. The results showed that between both male and female juveniles and adult males and females, the difference in thickness of each layer is not significant. But the difference in quantity of mitral cells between adult males and females was significant. Meanwhile, the structure of every layer in juvenile dogs was apparent while the volume and the weight of adult dogs＇ olfactory bulb and each layer＇s width increased significantly. On the other hand, the density of each layer＇s cells decreased apparently. Our results demonstrated that the olfactory bulb developed with age, and the apparent differences in morphology and quantity of mitral cells between males and females may be one of the reasons leading to the sexual variations of olfactory sensitivity.
基金Supported by Special Fund for the Dominant Subjects Development of the Higher Education Institutions of Jiangsu ProvinceScience and Technology Innovation Fund of Nanjing Forestry University(X09-120-4)~~
文摘[Objective] The purpose of this study is to investigate the effects of differ- ent phytohormones on the adventitious bud differentiation of oriental lily. [Method] The bulb scales of the test-tube plantlets of Tiber, Rodina and Constanta were cul- tured in media supplemented with different cytokinin and auxin at different concen- tration, and then the adventitious buds in each treatment were calculated. [Result] Cytokinins had different influence on the adventitious bud differentiation of the three oriental lily cultivars. Among them, 6-BA had the best effect to induce the adventi- tious bud differentiation from bulb scales of Tiber and Rodina, but there was some difference in the optimal concentration. KT had the best effect to induce the adven- titious bud differentiation of Constanta. The auxins had little influence on the quality of the adventitious bud of the three oriental lily cultivars, but caused some difference in differentiation coefficients. [Conclusion] The most suitable media for the adventi- tious bud differentiation from bulb scales in vitro of Tiber, Rodina and Constanta were MS＋0.2 mg/L 6-BA＋0.2 mg/L 2,4-D, MS＋I.0 mg/L 6-BA＋0.2 mg/L IAA, MS＋ 1.0 mg/L KT＋0.5 mg/L 2,4-D, respectively.
文摘An equation model for calculating the adiabatic temperature of the wet-bulb thermometer has been obtained empirical fit through a meteorological database, specificly a trough relative humidity and air temperature. A comparison of the results of calculations with the use of this equation and from meteorological database was made. The model deducted of the comparison is valid for a dry bulb temperature range of 3°C to 35°C and for relative humidity percentage in a range of 7% to 97%. Normalized errors are less than 5.5%. It means a maximum variation of 0.55°C from data. However, this variation from error represents only 3.6% of the data sample. The equation model was satisfactory.
文摘The dynamics of the growth of roots and leaves of the Allium cepa L. after the mechanical removal of a part of the root system or the bulb was studied. It was shown that, after surgical interference, the potency for organogenesis is retained, although it is weakened.
文摘<strong>Objectives:</strong> Pulsatile tinnitus involves a wide spectrum of etiologies. The etiologies include normal vascular variants, temporal bone tumor, acquired vascular lesions and chronic middle ear inflammatory diseases. Jugular bulb diverticulum is a rare cause of pulsatile tinnitus. We report one case of jugular diverticulum presenting with pulsatile tinnitus and its surgical management and outcome. <strong>Case Report:</strong> A 36-year-old woman with a history of uterine myoma and chronic anemia presented with right pulsatile tinnitus that was worsening in recent one month. Neurological exam was normal. ENT evaluation revealed no abnormalities via otoscopy and physical examination. The CT scan revealed right dominant jugular bulb with diverticulum projecting to posterior ear canal wall. We performed jugular bulb diverticulum resurfacing with temporalis fascia, Surgicel<sup>®</sup> and Gelfoam<sup>®</sup>, and bone wax via transmastoid approach. The symptom improved postoperative immediately. No major complications were noted during outpatient clinic follow-up. <strong>Conclusion:</strong> Transmastoid resurfacing of jugular bulb diverticulum is an effective management of pulsatile tinnitus from this kind vascular anomaly.
基金supported by the Hunan Provincial Innovation Foundation for Postgraduate in China,No.CX2014B099(to XH)the Science Foundation of Hunan Provincial Education Department of China,No.11C1264(to FJD),13C958(to XH)
文摘The main active components extracted from Panax notoginseng are total saponins. They have been shown to inhibit platelet aggregation, increase cerebral blood flow, improve neurological behavior, decrease infarct volume and promote proliferation and differentiation of neural stem cells in the hippocampus and lateral ventricles. However, there is a lack of studies on whether total saponins of Panax notoginsertg have potential benefits on immature neuroblasts in the olfactory bulb following ischemia and reperfusion. This study established a rat model of global cerebral ischemia and reperfusion using four-vessel occlusion. Rats were administered total sa- ponins of Panax notoginseng at 75 mg/kg intraperitoneally 30 minutes after ischemia then once a day, for either 7 or 14 days. Total saponins of Panax notoginseng enhanced the number of dou- blecortin （DCX）＋ neural progenitor ceils and increased co-localization of DCX with neuronal nuclei and phosphorylated cAMP response element-binding/DCX＋ neural progenitor cells in the olfactory bulb at 7 and 14 days post ischemia. These findings indicate that following global brain ischemia/reperfusion, total saponins of Panax notoginseng promote differentiation of DCX＋ cells expressing immature neuroblasts in the olfactory bulb and the underlying mechanism is related to the activation of the signaling pathway of cyclic adenosine monophosphate response element binding protein.
基金supported by grants from the National Natural Science Foundation of China (31400946, 31671120, 31771197, 31329001, 31771156, 91632303, and 81661148053/H09)the Strategic Priority Research Program of Chinese Academy of Science (XDB32030200)the National Basic Research Development Program (973 Program) of China (2015CB755600)
文摘Sensory processing is strongly modulated by different brain and behavioral states,and this is based on the top-down modulation.In the olfactory system,local neural circuits in the olfactory bulb(OB)are innervated by centrifugal afferents in order to regulate the processing of olfactory information in the OB under different behavioral states.The purpose of the present study was to explore the organization of neural networks in olfactory-related cortices and modulatory nuclei that give rise to direct and indirect innervations to the glomerular layer(GL)of the OB at the whole-brain scale.Injection of different recombinant attenuated neurotropic viruses into the GL showed that it received direct inputs from each layer in the OB,centrifugal inputs from the ipsilateralanterior olfactory nucleus(AON),anterior piriform cortex(Pir),and horizontal limb of diagonal band of Broca(HDB),and various indirect inputs from bilateral cortical neurons in the AON,Pir,amygdala,entorhinal cortex,hippocampus,HDB,dorsal raphe,median raphe and locus coeruleus.These results provide a circuitry basis that will help further understand the mechanism by which olfactory informationprocessing in the OB is regulated.
基金supported by the National Natural Science Foundation of China,No.81560084,81560208a grant from the Project of Superior Discipline Groups in Ningxia Medical University of China,No.XY201414
文摘Hyperhomocysteinemia has been shown to be associated with neurodegenerative diseases; however, lesions or histological changes and mechanisms underlying homocysteine-induced injury in olfactory bulb neurons remain unclear. In this study, hyperhomocysteinemia was induced in apolipoprotein E-deficient mice with 1.7% methionine. Pathological changes in the olfactory bulb were observed through hematoxylin-eosin and Pischingert staining. Cell apoptosis in the olfactory bulb was determined through terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） staining. Transmission electron microscopy revealed an abnormal ultrastructure of neurons. Furthermore, immunoreactivity and expression of the hairy enhancer of the split 1 （Hesl） and Hess were measured using immunohistochemistry, immunofluorescence, and western blot assay. Our results revealed no significant structural abnormality in the ol- factory bulb of hyperhomocysteinemic mice. However, the number of TUNEL-positive cells increased in the olfactory bulb, lipofuscin and vacuolization were visible in mitochondria, and the expression of Hes1 and Hes5 decreased. These findings confirm that hyperhomocyste- inemia induces injury in olfactory bulb neurons by downregulating Hes1 and Hes5 expression.
基金supported by National Natural Science Foundation of China (Grant Nos. 50879026, 50679027)
文摘With the increasing demand for the clean sustainable power, the turbine design urgently turns to increase the capability significantly toward higher head for generating larger power. Currently, there are many studies in the field of the bulb turbine with single-stage runner, though reports about counter-rotating tandem-runner are rare. However, the further high-head application with the single-stage runner is very difficult to achieve due to the limit of the specific speed. In this paper, a new bulb turbine with the tandem-runner is designed in order to substantially increase the applicable limit toward higher head with larger power. A half of the net head is absorbed by the frontal runner which can generate output power, while the remaining half is absorbed by the rear runner. To generate the Euler energy required for the rear runner, the frontal runner has the counter-rotation against the rear runner so that the counter-rotating tandem-runner can meet the purpose of double head and power under the same size as the conventional bulb turbine. Supply and demand of Euler energy between the two runners are thoroughly optimized through the detailed flow analysis, in order to secure the stable operation. As a result, the interference of Euler energies between the outflow from the frontal runner and the inflow to the rear runner is confirmed to be very small on the counter-rotating interface between the two runners. The prediction method of on-cam performance between the two adjustable runners is also developed numerically, which provides optimal flow between the two runners. This research provides a theoretical basis for the optimal design and operation of the counter-rotating tandem-runner bulb turbines.
基金Liaoning Provincial Department of Education-Funded Project, No. 20068040the Experimental Center of Shenyang Normal University Foundation, No. 2008007
文摘Microelectrode technique was used to record the spontaneous electrical activities of the neurons in olfactory bulb of the Bufo bufo gargarizans, both in hibernation and after hibemation. This study investigated the electrophysiological characteristics of amphibian olfactory bulb in the period of hibernation and after hibernation and its effects on the start of hibernation and spontaneous awakening. The research showed four forms of spontaneous firings： single spontaneous firing, burst spontaneous firing, irregular spontaneous firing and consecutive single spontaneous firing. The single spontaneous firing includes slow depolarized spontaneous firing and fast depolarized spontaneous firing, and the slow depolarized spontaneous firing occurs only during the hibernation period. In hibernation, the low amplitude and low frequency firing with a longer duration may be relevant to maintaining the tonicity of the central nervous system in toads that are in hibernation, and this kind of firing may also provide an excited basis for their arousal from hibernation. After hibernation, the amplitude and frequency of firing increase, but the firing duration gets shorter. This form of short-term firing, which may be a phenomenon of sensory neurons fast adapting, is one of the neuronal mechanisms for the arousal of hibernating animals.
