Glutamatergic projection neurons generate sophisticated excitatory circuits to integrate and transmit information among different cortical areas,and between the neocortex and other regions of the brain and spinal cord...Glutamatergic projection neurons generate sophisticated excitatory circuits to integrate and transmit information among different cortical areas,and between the neocortex and other regions of the brain and spinal cord.Appropriate development of cortical projection neurons is regulated by certain essential events such as neural fate determination,proliferation,specification,differentiation,migration,survival,axonogenesis,and synaptogenesis.These processes are precisely regulated in a tempo-spatial manner by intrinsic factors,extrinsic signals,and neural activities.The generation of correct subtypes and precise connections of projection neurons is imperative not only to support the basic cortical functions(such as sensory information integration,motor coordination,and cognition)but also to prevent the onset and progression of neurodevelopmental disorders(such as intellectual disability,autism spectrum disorders,anxiety,and depression).This review mainly focuses on the recent progress of transcriptional regulations on the development and diversity of neocortical projection neurons and the clinical relevance of the failure of transcriptional modulations.展开更多
Retrograde adeno-associated viruses(AAVs)are capable of infecting the axons of projection neurons and serve as a powerful tool for the anatomical and functional characterization of neural networks.However,few retro-gr...Retrograde adeno-associated viruses(AAVs)are capable of infecting the axons of projection neurons and serve as a powerful tool for the anatomical and functional characterization of neural networks.However,few retro-grade AAV capsids have been shown to offer access to cor-tical projection neurons across different species and enable the manipulation of neural function in non-human primates(NHPs).Here,we report the development of a novel retro-grade AAV capsid,AAV-DJ8R,which efficiently labeled cortical projection neurons after local administration into the striatum of mice and macaques.In addition,intrastriatally injected AAV-DJ8R mediated opsin expression in the mouse motor cortex and induced robust behavioral alterations.Moreover,AAV-DJ8R markedly increased motor cortical neuron firing upon optogenetic light stimulation after viral delivery into the macaque putamen.These data demonstrate the usefulness of AAV-DJ8R as an efficient retrograde tracer for cortical projection neurons in rodents and NHPs and indicate its suitability for use in conducting functional interrogations.展开更多
Autapses selectively form in specific cell types in many brain regions.Previous studies have also found putative autapses in principal spiny projection neurons(SPNs)in the striatum.However,it remains unclear whether t...Autapses selectively form in specific cell types in many brain regions.Previous studies have also found putative autapses in principal spiny projection neurons(SPNs)in the striatum.However,it remains unclear whether these neurons indeed form physiologically functional autapses.We applied whole-cell recording in striatal slices and identified autaptic cells by the occurrence of prolonged asynchronous release(AR)of neurotransmitters after bursts of high-frequency action potentials(APs).Surprisingly,we found no autaptic AR in SPNs,even in the presence of Sr^(2+).However,robust autaptic AR was recorded in parvalbumin(PV)-expressing neurons.The autaptic responses were mediated by GABA_(A) receptors and their strength was dependent on AP frequency and number.Further computer simulations suggest that autapses regulate spiking activity in PV cells by providing self-inhibition and thus shape network oscillations.Together,our results indicate that PV neurons,but not SPNs,form functional autapses,which may play important roles in striatal functions.展开更多
The γ-aminobutyric acid neurons（GABAergic neurons） in the inferior colliculus are classified into various patterns based on their intrinsic electrical properties to a constant current injection. Although this class...The γ-aminobutyric acid neurons（GABAergic neurons） in the inferior colliculus are classified into various patterns based on their intrinsic electrical properties to a constant current injection. Although this classification is associated with physiological function, the exact role for neurons with various firing patterns in acoustic processing remains poorly understood. In the present study, we analyzed characteristics of inferior colliculus neurons in vitro, and recorded responses to stimulation of the dorsal nucleus of the lateral lemniscus using the wholecell patch clamp technique. Seven inferior colliculus neurons were tested and were classified into two firing patterns： sustained-regular（n = 4） and sustained-adapting firing patterns（n = 3）. The majority of inferior colliculus neurons exhibited slight changes in response to stimulation and bicuculline. The responses of one neuron with a sustained-adapting firing pattern were suppressed after stimulation, but recovered to normal levels following application of the γ-aminobutyric acid receptor antagonist. One neuron with a sustained-regular pattern showed suppressed stimulation responses, which were not affected by bicuculline. Results suggest that GABAergic neurons in the inferior colliculus exhibit sustained-regular or sustained-adapting firing patterns. Additionally, GABAergic projections from the dorsal nucleus of the lateral lemniscus to the inferior colliculus are associated with sound localization. The different neuronal responses of various firing patterns suggest a role in sound localization. A better understanding of these mechanisms and functions will provide better clinical treatment paradigms for hearing deficiencies.展开更多
Neuroanatomical studies have shown that there are single and double projection neurons in the spinal cord dorsal horn. The cell origin, axon traveling and properties of these neurons have been investigated morphologic...Neuroanatomical studies have shown that there are single and double projection neurons in the spinal cord dorsal horn. The cell origin, axon traveling and properties of these neurons have been investigated morphologically and physiologically. The solitary tract nucleus (STN)in the brain stem, as a nucleus responsible for processing visceral sensa-展开更多
Objective It has been reported that B-cell lymphoma 2 （Bcl-2） enhances neurogenesis as well as supporting axonal growth after injury. In the present study, we investigated whether Bcl-2 overexpression plays a role i...Objective It has been reported that B-cell lymphoma 2 （Bcl-2） enhances neurogenesis as well as supporting axonal growth after injury. In the present study, we investigated whether Bcl-2 overexpression plays a role in the formation of newborn striatonigral projection neurons in the adult rat brain after transient middle cerebral artery occlusion （MCAO）. Methods We infused human Bcl-2-expressing plasmid （pBcl-2） into the lateral ventricle immediately after 30 min of MCAO, injected 5＇-bromodeoxyuridine （BrdU） intraperitoneally to label proliferative cells, and microinjected fluorogold （FG） into the substantia nigra at 11 weeks of reperfusion followed by multiple immunostaining of striatonigral projection neurons at 12 weeks. Results We found that pBcl-2 treatment significantly increased the number of newborn neurons （BrdU＋-NeuN＋） in the striatum ipsilateral to the MCAO. We further detected newborn striatonigral projection neurons （BrdU＋-FG＋-NeuN＋） in the ipsilateral striatum at 12 weeks. More interestingly, the number of newborn striatonigral projection neurons （BrdU＋-FG＋） was significantly increased by pBcl-2 treatment compared to that by pEGFP, a control plasmid. Conclusion Taken together, we found that Bcl-2 overexpression in the brain enhanced the generation of newborn striatonigral projection neurons. This provides a potential strategy for promoting the reestablishment of neural networks and brain repair after ischemic injury.展开更多
The accessory olfactory bulb(AOB), located at the posterior dorsal aspect of the main olfactory bulb(MOB), is the first brain relay of the accessory olfactory system(AOS), which can parallelly detect and process volat...The accessory olfactory bulb(AOB), located at the posterior dorsal aspect of the main olfactory bulb(MOB), is the first brain relay of the accessory olfactory system(AOS), which can parallelly detect and process volatile and nonvolatile social chemosignals and mediate different sexual and social behaviors with the main olfactory system(MOS). However, due to its anatomical location and absence of specific markers, there is a lack of research on the internal and external neural circuits of the AOB. This issue was addressed by singlecolor labeling and fluorescent double labeling using retrograde rAAVs injected into the bed nucleus of the stria terminalis(BST), anterior cortical amygdalar area(ACo), medial amygdaloid nucleus(MeA), and posteromedial cortical amygdaloid area(PMCo) in mice. We demonstrated the effectiveness of this AOB projection neuron labeling method and showed that the mitral cells of the AOB exhibited efferent projection dispersion characteristics similar to those of the MOB. Moreover, there were significant differences in the number of neurons projected to different brain regions, which indicated that each mitral cell in the AOB could project to a different number of neurons in different cortices. These results provide a circuitry basis to help understand the mechanism by which pheromone information is encoded and decoded in the AOS.展开更多
OBJECTIVE The high prevalence of sleep disturbance has been found in patients with striatum-related neurodegenerative disorders.In the striatum,there are abundant adenosine A2A receptors(A2ARs)whichhavebeen reported t...OBJECTIVE The high prevalence of sleep disturbance has been found in patients with striatum-related neurodegenerative disorders.In the striatum,there are abundant adenosine A2A receptors(A2ARs)whichhavebeen reported to mediatesleepbehavior for adenosine.We hypothesized that the A2AR-expressing neurons in the striatum are involved in sleep-wake regulation.METHODS We employed a chemogenetic technique,designer receptor exclusively activated by designer drug(DREADD),to specifically and non-invasively manipulate the neuron activity based on the principle of Cre/Lox P recombination,EEG/electromyogram recording for sleep-wake behaviors,the neural tracing approach toselectively visualize the perikarya of A2AR-expressing neurons and their axons by adeno-associated virus(AAV)encoding humanized Renilla green fluorescent(hr GFP)as a tracerin A2AR-Cre mice.In addition,we used immunoelectron microscopy,patch-clamp technique,and optogenetics in A2AR-Cre mice to selectively characterize the synapse and functional connectivity between the A2AR-expressing neurons and the neuron of their downstream targets in vitro.RESULTS The activation of A2AR-expressing neurons in rostral,centromedial and centrolateral striatum increased non-rapid eye movement(non-REM,NREM)sleep,concomitant with a reduction in wakefulness,whereas the activation of A2AR-expressing neurons in caudal striatum didn′t alter sleep-wake profiles at all.Topographical projections in the sagittal section showed that the axons of A2ARexpressing neurons from rostral striatum distributed in the rostral external globuspallidus(GPe)with a discoidal region paralleled to the striato-pallidal border,while the axons of the A2AR-expressing neurons from the central striatum not only distributed in the rostral GPe,but also in the caudal GPe with a similar distributing pattern as did in rostral neurons.However,the axons of A2ARexpressing neurons from caudal striatum just scattered in the caudal GPe.Based on our anatomical findings and patch-clamp technique combining with optogenetic展开更多
基金supported by Guangdong Provincial Basic and Applied Basic Research Fund,No.2021A1515011299(to KT)。
文摘Glutamatergic projection neurons generate sophisticated excitatory circuits to integrate and transmit information among different cortical areas,and between the neocortex and other regions of the brain and spinal cord.Appropriate development of cortical projection neurons is regulated by certain essential events such as neural fate determination,proliferation,specification,differentiation,migration,survival,axonogenesis,and synaptogenesis.These processes are precisely regulated in a tempo-spatial manner by intrinsic factors,extrinsic signals,and neural activities.The generation of correct subtypes and precise connections of projection neurons is imperative not only to support the basic cortical functions(such as sensory information integration,motor coordination,and cognition)but also to prevent the onset and progression of neurodevelopmental disorders(such as intellectual disability,autism spectrum disorders,anxiety,and depression).This review mainly focuses on the recent progress of transcriptional regulations on the development and diversity of neocortical projection neurons and the clinical relevance of the failure of transcriptional modulations.
基金supported by Ministry of Science and Technology of China(2019YFA0903803 and 2018YFA0801404)National Natural Science Foundation of China(31871090,32000730,81961128019,and 81901397)+7 种基金Shenzhen Science and Technology Innovation Commission(JCYJ20190809171003698,JCYJ202103243001018,JCYJ20180507182505475,and JCYJ20180504165804015)Shenzhen Technological Research Center for Primate Translational Medicine(F-2021-Z99-504979)Youth Innovation Promotion Association(CAS 2017120)Chinese Academy of Sciences International Partnership Program(172644KYSB20170004)China Postdoctoral Science Foundation(2019M653115.)CAS Key Laboratory of Brain Connectome and Manipulation(2019DP173024)Guangdong Provincial Key Laboratory of Brain Connectome and Behavior(2017B030301017)International Science and Technology Cooperation Base of Guangdong Province(2019A050505008).
文摘Retrograde adeno-associated viruses(AAVs)are capable of infecting the axons of projection neurons and serve as a powerful tool for the anatomical and functional characterization of neural networks.However,few retro-grade AAV capsids have been shown to offer access to cor-tical projection neurons across different species and enable the manipulation of neural function in non-human primates(NHPs).Here,we report the development of a novel retro-grade AAV capsid,AAV-DJ8R,which efficiently labeled cortical projection neurons after local administration into the striatum of mice and macaques.In addition,intrastriatally injected AAV-DJ8R mediated opsin expression in the mouse motor cortex and induced robust behavioral alterations.Moreover,AAV-DJ8R markedly increased motor cortical neuron firing upon optogenetic light stimulation after viral delivery into the macaque putamen.These data demonstrate the usefulness of AAV-DJ8R as an efficient retrograde tracer for cortical projection neurons in rodents and NHPs and indicate its suitability for use in conducting functional interrogations.
基金supported by the National Natural Science Foundation of China(32130044,31630029,32171094,and 32100930)the National Key Research and Development Program of China(2021ZD0202500).
文摘Autapses selectively form in specific cell types in many brain regions.Previous studies have also found putative autapses in principal spiny projection neurons(SPNs)in the striatum.However,it remains unclear whether these neurons indeed form physiologically functional autapses.We applied whole-cell recording in striatal slices and identified autaptic cells by the occurrence of prolonged asynchronous release(AR)of neurotransmitters after bursts of high-frequency action potentials(APs).Surprisingly,we found no autaptic AR in SPNs,even in the presence of Sr^(2+).However,robust autaptic AR was recorded in parvalbumin(PV)-expressing neurons.The autaptic responses were mediated by GABA_(A) receptors and their strength was dependent on AP frequency and number.Further computer simulations suggest that autapses regulate spiking activity in PV cells by providing self-inhibition and thus shape network oscillations.Together,our results indicate that PV neurons,but not SPNs,form functional autapses,which may play important roles in striatal functions.
基金supported by the National Natural Science Foundation of China,No.81271090
文摘The γ-aminobutyric acid neurons（GABAergic neurons） in the inferior colliculus are classified into various patterns based on their intrinsic electrical properties to a constant current injection. Although this classification is associated with physiological function, the exact role for neurons with various firing patterns in acoustic processing remains poorly understood. In the present study, we analyzed characteristics of inferior colliculus neurons in vitro, and recorded responses to stimulation of the dorsal nucleus of the lateral lemniscus using the wholecell patch clamp technique. Seven inferior colliculus neurons were tested and were classified into two firing patterns： sustained-regular（n = 4） and sustained-adapting firing patterns（n = 3）. The majority of inferior colliculus neurons exhibited slight changes in response to stimulation and bicuculline. The responses of one neuron with a sustained-adapting firing pattern were suppressed after stimulation, but recovered to normal levels following application of the γ-aminobutyric acid receptor antagonist. One neuron with a sustained-regular pattern showed suppressed stimulation responses, which were not affected by bicuculline. Results suggest that GABAergic neurons in the inferior colliculus exhibit sustained-regular or sustained-adapting firing patterns. Additionally, GABAergic projections from the dorsal nucleus of the lateral lemniscus to the inferior colliculus are associated with sound localization. The different neuronal responses of various firing patterns suggest a role in sound localization. A better understanding of these mechanisms and functions will provide better clinical treatment paradigms for hearing deficiencies.
文摘Neuroanatomical studies have shown that there are single and double projection neurons in the spinal cord dorsal horn. The cell origin, axon traveling and properties of these neurons have been investigated morphologically and physiologically. The solitary tract nucleus (STN)in the brain stem, as a nucleus responsible for processing visceral sensa-
基金supported by grants from the National Basic Research Development Program of China (2006CB504100 and 2006CB943702)the National Natural Science Foundation of China(81030020 and J0730860)
文摘Objective It has been reported that B-cell lymphoma 2 （Bcl-2） enhances neurogenesis as well as supporting axonal growth after injury. In the present study, we investigated whether Bcl-2 overexpression plays a role in the formation of newborn striatonigral projection neurons in the adult rat brain after transient middle cerebral artery occlusion （MCAO）. Methods We infused human Bcl-2-expressing plasmid （pBcl-2） into the lateral ventricle immediately after 30 min of MCAO, injected 5＇-bromodeoxyuridine （BrdU） intraperitoneally to label proliferative cells, and microinjected fluorogold （FG） into the substantia nigra at 11 weeks of reperfusion followed by multiple immunostaining of striatonigral projection neurons at 12 weeks. Results We found that pBcl-2 treatment significantly increased the number of newborn neurons （BrdU＋-NeuN＋） in the striatum ipsilateral to the MCAO. We further detected newborn striatonigral projection neurons （BrdU＋-FG＋-NeuN＋） in the ipsilateral striatum at 12 weeks. More interestingly, the number of newborn striatonigral projection neurons （BrdU＋-FG＋） was significantly increased by pBcl-2 treatment compared to that by pEGFP, a control plasmid. Conclusion Taken together, we found that Bcl-2 overexpression in the brain enhanced the generation of newborn striatonigral projection neurons. This provides a potential strategy for promoting the reestablishment of neural networks and brain repair after ischemic injury.
基金supported by the National Natural Science Foundation of China(31400946,31771156,91632303/H09,91732304 and 31830035)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB32030200)。
文摘The accessory olfactory bulb(AOB), located at the posterior dorsal aspect of the main olfactory bulb(MOB), is the first brain relay of the accessory olfactory system(AOS), which can parallelly detect and process volatile and nonvolatile social chemosignals and mediate different sexual and social behaviors with the main olfactory system(MOS). However, due to its anatomical location and absence of specific markers, there is a lack of research on the internal and external neural circuits of the AOB. This issue was addressed by singlecolor labeling and fluorescent double labeling using retrograde rAAVs injected into the bed nucleus of the stria terminalis(BST), anterior cortical amygdalar area(ACo), medial amygdaloid nucleus(MeA), and posteromedial cortical amygdaloid area(PMCo) in mice. We demonstrated the effectiveness of this AOB projection neuron labeling method and showed that the mitral cells of the AOB exhibited efferent projection dispersion characteristics similar to those of the MOB. Moreover, there were significant differences in the number of neurons projected to different brain regions, which indicated that each mitral cell in the AOB could project to a different number of neurons in different cortices. These results provide a circuitry basis to help understand the mechanism by which pheromone information is encoded and decoded in the AOS.
基金The project supported by National Basic Research Program of China(2015CB856401)
文摘OBJECTIVE The high prevalence of sleep disturbance has been found in patients with striatum-related neurodegenerative disorders.In the striatum,there are abundant adenosine A2A receptors(A2ARs)whichhavebeen reported to mediatesleepbehavior for adenosine.We hypothesized that the A2AR-expressing neurons in the striatum are involved in sleep-wake regulation.METHODS We employed a chemogenetic technique,designer receptor exclusively activated by designer drug(DREADD),to specifically and non-invasively manipulate the neuron activity based on the principle of Cre/Lox P recombination,EEG/electromyogram recording for sleep-wake behaviors,the neural tracing approach toselectively visualize the perikarya of A2AR-expressing neurons and their axons by adeno-associated virus(AAV)encoding humanized Renilla green fluorescent(hr GFP)as a tracerin A2AR-Cre mice.In addition,we used immunoelectron microscopy,patch-clamp technique,and optogenetics in A2AR-Cre mice to selectively characterize the synapse and functional connectivity between the A2AR-expressing neurons and the neuron of their downstream targets in vitro.RESULTS The activation of A2AR-expressing neurons in rostral,centromedial and centrolateral striatum increased non-rapid eye movement(non-REM,NREM)sleep,concomitant with a reduction in wakefulness,whereas the activation of A2AR-expressing neurons in caudal striatum didn′t alter sleep-wake profiles at all.Topographical projections in the sagittal section showed that the axons of A2ARexpressing neurons from rostral striatum distributed in the rostral external globuspallidus(GPe)with a discoidal region paralleled to the striato-pallidal border,while the axons of the A2AR-expressing neurons from the central striatum not only distributed in the rostral GPe,but also in the caudal GPe with a similar distributing pattern as did in rostral neurons.However,the axons of A2ARexpressing neurons from caudal striatum just scattered in the caudal GPe.Based on our anatomical findings and patch-clamp technique combining with optogenetic
