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 retrograde AAV capsids have been shown to offer access to cortical 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 retrograde 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.
Animals ; Haplorhini ; Axons ; Motor Neurons ; Interneurons ; Macaca ; Dependovirus/genetics* ; Genetic Vectors

Neuronomodulation refers to the modulation of neural conduction and synaptic transmission (i.e., the conduction process involved in synaptic transmission) of excitable neurons via changes in the membrane potential in response to chemical substances, from spillover neurotransmitters to paracrine or endocrine hormones circulating in the blood. Neuronomodulation can be direct or indirect, depending on the transduction pathways from the ligand binding site to the ion pore, either on the same molecule, i.e. the ion channel, or through an intermediate step on different molecules. The major players in direct neuronomodulation are ligand-gated or voltage-gated ion channels. The key process of direct neuronomodulation is the binding and chemoactivation of ligand-gated or voltage-gated ion channels, either orthosterically or allosterically, by various ligands. Indirect neuronomodulation involves metabotropic receptor-mediated slow potentials, where steroid hormones, cytokines, and chemokines can implement these actions. Elucidating neuronomodulation is of great significance for understanding the physiological mechanisms of brain function, and the occurrence and treatment of diseases.
Ligands ; Neurons/metabolism* ; Synaptic Transmission/physiology* ; Ion Channels/metabolism* ; Hormones/metabolism*

Astrocytes are the largest glial population in the mammalian brain. However, we have a minimal understanding of astrocyte development, especially fate specification in different regions of the brain. Through lineage tracing of the progenitors of the third ventricle (3V) wall via in-utero electroporation in the embryonic mouse brain, we show the fate specification and migration pattern of astrocytes derived from radial glia along the 3V wall. Unexpectedly, radial glia located in different regions along the 3V wall of the diencephalon produce distinct cell types: radial glia in the upper region produce astrocytes and those in the lower region produce neurons in the diencephalon. With genetic fate mapping analysis, we reveal that the first population of astrocytes appears along the zona incerta in the diencephalon. Astrogenesis occurs at an early time point in the dorsal region relative to that in the ventral region of the developing diencephalon. With transcriptomic analysis of the region-specific 3V wall and lateral ventricle (LV) wall, we identified cohorts of differentially-expressed genes in the dorsal 3V wall compared to the ventral 3V wall and LV wall that may regulate astrogenesis in the dorsal diencephalon. Together, these results demonstrate that the generation of astrocytes shows a spatiotemporal pattern in the developing mouse diencephalon.
Mice ; Animals ; Astrocytes ; Neuroglia/physiology* ; Diencephalon ; Brain ; Neurons ; Mammals

The purpose of this study was to investigate the effects of post-traumatic stress disorder (PTSD) on electrophysiological characteristics of glutamatergic and GABAergic neurons in dorsal hippocampus (dHPC) and ventral hippocampus (vHPC) in mice, and to elucidate the mechanisms underlying the plasticity of hippocampal neurons and memory regulation after PTSD. Male C57Thy1-YFP/GAD67-GFP mice were randomly divided into PTSD group and control group. Unavoidable foot shock (FS) was applied to establish PTSD model. The spatial learning ability was explored by water maze test, and the changes in electrophysiological characteristics of glutamatergic and GABAergic neurons in dHPC and vHPC were examined using whole-cell recording method. The results showed that FS significantly reduced the movement speed, and enhanced the number and percentage of freezing. PTSD significantly prolonged the escape latency in localization avoidance training, shortened the swimming time in the original quadrant, extended the swimming time in the contralateral quadrant, and increased absolute refractory period, energy barrier and inter-spike interval of glutamatergic neurons in dHPC and GABAergic neurons in vHPC, while decreased absolute refractory period, energy barrier and inter-spike interval of GABAergic neurons in dHPC and glutamatergic neurons in vHPC. These results suggest that PTSD can damage spatial perception of mice, down-regulate the excitability of dHPC and up-regulate the excitability of vHPC, and the underlying mechanism may involve the regulation of spatial memory by the plasticity of neurons in dHPC and vHPC.
Mice ; Male ; Animals ; Stress Disorders, Post-Traumatic ; Hippocampus ; Spatial Learning ; GABAergic Neurons

OBJECTIVE: To summarize the research progress of stem cell transplantation in treating spinal cord injury (SCI) at different stages based on the pathophysiological mechanism of SCI. METHODS: The relevant research literature at home and abroad was extensively reviewed to explore the impact of transplantation timing on the effectiveness of stem cell transplantation in treating SCI. RESULTS: Researchers performed different types of stem cell transplantation for subjects at different stages of SCI through different transplantation approaches. Clinical trials have proved the safety and feasibility of stem cell transplantation at acute, subacute, and chronic stages, which can alleviate inflammation at the injured site and restore the function of the damaged nerve cells. But the reliable clinical trials comparing the effectiveness of stem cell transplantation at different stages of SCI are still lacking. CONCLUSION Stem cell transplantation has a good prospect in treating SCI. In the future, the multi-center, large sample randomized controlled clinical trials are needed, with a focus on the long-term effectiveness of stem cell transplantation.
Humans ; Hematopoietic Stem Cell Transplantation ; Neurons ; Recovery of Function/physiology* ; Spinal Cord ; Spinal Cord Injuries/surgery* ; Stem Cell Transplantation

Objective To investigate the protective effect of resveratrol (RSV) on improving cognitive function in severely burned rats and its possible mechanism. Methods 18 male SD rats aged 18-20 months were randomly divided into 3 groups: control group, model group and RSV group, with 6 rats in each group. After successful modeling, the rats in RSV group were gavaged once daily with RSV (20 mg/kg). Meanwhile, the rats in control group and model group were gavaged once daily with an equal volume of sodium chloride solution. After 4 weeks, the cognitive function of all rats was estimated by Step-down Test. The concentration of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) protein in serum of rats were detected by ELISA. The expression of IL-6, TNF-α mRNA and protein were estimated by real-time PCR and Western blotting. The apoptosis of hippocampal neurons was tested by terminal deoxynuclectidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL). The expression of nuclear transcription factor-κB (NF-κB)/c-Jun N-terminal kinase (JNK) pathway-related proteins in hippocampus were assessed by Western blotting. Results Compared with the rats in model group, rats in RSV group exhibited improved cognitive function. Consistently, the rats in RSV group had a reduced concentration of TNF-α and IL-6 in serum, decreased mRNA and protein expressions of TNF-α and IL-6 in hippocampus, and decreased apoptosis rate and relative expression of p-NF-κB p65/NF-κB p65 and p-JNK/JNK in hippocampal neurons. Conclusion RSV alleviates inflammatory response and hippocampal neuronal apoptosis by inhibiting NF-κB/JNK pathway, thereby improving cognitive function in severely burned rats.
Resveratrol/pharmacology* ; Male ; Animals ; Rats ; Rats, Sprague-Dawley ; Burns/drug therapy* ; Cognition/drug effects* ; Hippocampus/metabolism* ; MAP Kinase Signaling System ; NF-kappa B/metabolism* ; Tumor Necrosis Factor-alpha/blood* ; Interleukin-6/blood* ; Neurons/drug effects* ; Apoptosis

OBJECTIVES: Nerve growth factor (NGF) induces neuron transdifferentiation of adrenal medulla chromaffin cells (AMCCs) and consequently downregulates the secretion of epinephrine (EPI), which may be involved in the pathogenesis of bronchial asthma. Mammalian achaete scute-homologous 1 (MASH1), a key regulator of neurogenesis in the nervous system, has been proved to be elevated in AMCCs with neuron transdifferentiation in vivo. This study aims to explore the role of MASH1 in the process of neuron transdifferentiation of AMCCs and the mechanisms. METHODS: Rat AMCCs were isolated and cultured. AMCCs were transfected with siMASH1 or MASH1 overexpression plasmid, then were stimulated with NGF and/or dexamethasone, PD98059 (a MAPK kinase-1 inhibitor) for 48 hours. Morphological changes were observed using light and electron microscope. Phenylethanolamine-N-methyltransferase (PNMT, the key enzyme for epinephrine synthesis) and tyrosine hydroxylase were detected by immunofluorescence. Western blotting was used to test the protein levels of PNMT, MASH1, peripherin (neuronal markers), extracellular regulated protein kinases (ERK), phosphorylated extracellular regulated protein kinases (pERK), and JMJD3. Real-time RT-PCR was applied to analyze the mRNA levels of MASH1 and JMJD3. EPI levels in the cellular supernatant were measured using ELISA. RESULTS: Cells with both tyrosine hydroxylase and PNMT positive by immunofluorescence were proved to be AMCCs. Exposure to NGF, AMCCs exhibited neurite-like processes concomitant with increases in pERK/ERK, peripherin, and MASH1 levels (all P<0.05). Additionally, impairment of endocrine phenotype was proved by a signifcant decrease in the PNMT level and the secretion of EPI from AMCCs (all P<0.01). MASH1 interference reversed the effect of NGF, causing increases in the levels of PNMT and EPI, conversely reduced the peripherin level and cell processes (all P<0.01). MASH1 overexpression significantly increased the number of cell processes and peripherin level, while decreased the levels of PNMT and EPI (all P<0.01). Compared with the NGF group, the levels of MASH1, JMJD3 protein and mRNA in AMCCs in the NGF+PD98059 group were decreased (all P<0.05). After treatment with PD98059 and dexamethasone, the effect of NGF on promoting the transdifferentiation of AMCCs was inhibited, and the number of cell processes and EPI levels were decreased (both P<0.05). In addition, the activity of the pERK/MASH1 pathway activated by NGF was also inhibited. CONCLUSIONS MASH1 is the key factor in neuron transdifferentiation of AMCCs. NGF-induced neuron transdifferentiation is probably mediated via pERK/MASH1 signaling.
Animals ; Rats ; Adrenal Medulla ; Cell Transdifferentiation ; Chromaffin Cells ; Dexamethasone ; Epinephrine/pharmacology* ; Mammals ; Nerve Growth Factor ; Neurons ; Peripherins ; Protein Kinases ; Tyrosine 3-Monooxygenase

OBJECTIVE: To explore the regulatory effects of GABAergic neurons in the zona incerta (ZI) on sevoflurane and propofol anesthesia. METHODS: Forty-eight male C57BL/6J mice divided into 8 groups (n=6) were used in this study. In the study of sevoflurane anesthesia, chemogenetic experiment was performed in 2 groups of mice with injection of either adeno-associated virus carrying hM3Dq (hM3Dq group) or a virus carrying only mCherry (mCherry group). The optogenetic experiment was performed in another two groups of mice injected with an adeno-associated virus carrying ChR2 (ChR2 group) or GFP only (GFP group). The same experiments were also performed in mice for studying propofol anesthesia. Chemogenetics or optogenetics were used to induce the activation of GABAergic neurons in the ZI, and their regulatory effects on anesthesia induction and arousal with sevoflurane and propofol were observed; EEG monitoring was used to observe the changes in sevoflurane anesthesia maintenance after activation of the GABAergic neurons. RESULTS: In sevoflurane anesthesia, the induction time of anesthesia was significantly shorter in hM3Dq group than in mCherry group (P < 0.05), and also shorter in ChR2 group than in GFP group (P < 0.01), but no significant difference was found in the awakening time between the two groups in either chemogenetic or optogenetic tests. Similar results were observed in chemogenetic and optogenetic experiments with propofol (P < 0.05 or 0.01). Photogenetic activation of the GABAergic neurons in the ZI did not cause significant changes in EEG spectrum during sevoflurane anesthesia maintenance. CONCLUSION Activation of the GABAergic neurons in the ZI promotes anesthesia induction of sevoflurane and propofol but does not affect anesthesia maintenance or awakening.
Male ; Animals ; Mice ; Mice, Inbred C57BL ; Propofol/pharmacology* ; Sevoflurane/pharmacology* ; Zona Incerta ; Anesthesia, General ; GABAergic Neurons

OBJECTIVE: To investigate the variations in the expression of voltage-gated sodium (Na_v) channel subunits during development of rat cerebellar Purkinje neurons and their correlation with maturation of electrophysiological characteristics of the neurons. METHODS: We observed the changes in the expression levels of Na_V1.1, 1.2, 1.3 and 1.6 during the development of Purkinje neurons using immunohistochemistry in neonatal (5-7 days after birth), juvenile (12-14 days), adolescent (21-24 days), and adult (42-60 days) SD rats. Using whole-cell patch-clamp technique, we recorded the spontaneous electrical activity of the neurons in ex vivo brain slices of rats of different ages to analyze the changes of electrophysiological characteristics of these neurons during development. RESULTS: The expression of Na_V subunits in rat cerebellar Purkinje neurons showed significant variations during development. Na_V1.1 subunit was highly expressed throughout the developmental stages and increased progressively with age (P < 0.05). Na_V1.2 expression was not detected in the neurons in any of the developmental stages (P > 0.05). The expression level of Na_V1.3 decreased with development and became undetectable after adolescence (P < 0.05). Na_V1.6 expression was not detected during infancy, but increased with further development (P < 0.05). Na_V1.1 and Na_V1.3 were mainly expressed in the early stages of development. With the maturation of the rats, Na_V1.3 expression disappeared and Na_V1.6 expression increased in the neurons. Na_V1.1 and Na_V1.6 were mainly expressed after adolescence. The total Na_V protein level increased gradually with development (P < 0.05) and tended to stabilize after adolescence. The spontaneous frequency and excitability of the Purkinje neurons increased gradually with development and reached the mature levels in adolescence. The developmental expression of Na_V subunits was positively correlated with discharge frequency (r=0.9942, P < 0.05) and negatively correlated with the excitatory threshold of the neurons (r=0.9891, P < 0.05). CONCLUSION The changes in the expression levels of Na_V subunits are correlated with the maturation of high frequency electrophysiological properties of the neurons, suggesting thatmature Na_V subunit expressions is the basis of maturation of electrophysiological characteristics of the neurons.
Rats ; Animals ; Purkinje Cells/physiology* ; Rats, Sprague-Dawley ; Neurons ; Brain ; Sodium/metabolism*

Objective: To investigate the feasibility of isolation and culture of human adenoid-derived mesenchymal stem cells (aMSCs) in vitro, and to observe the differentiation of aMSCs into olfactory sensory neurons. Methods: Adenoid tissues surgically removed from children with adenoid hypertrophy in the Second Xiangya Hospital of Central South University from September to November of 2020 were collected. The adenoid tissues were digested and isolated by trypsin and then cultured with adhesion method. The expressions of cell surface antigens CD45, CD73 and CD90 on aMSCs of P5 generation were tested by flow cytometry, and the ability of osteogenic and adipogenic induction were used to identify cell differentiation ability. Then, aMSCs were induced into differentiation by retinoic acid (RA), sonic hedgehog (SHH), basic fibroblast growth factor (bFGF), RA+SHH, RA+bFGF, SHH+bFGF and RA+SHH+bFGF, respectively. The morphology of differentiated cells was observed under inverted microscope. The expression of β-tubulin 3, which was the specific marker of sensory neuron, the expressions of growth associated protein-43 (GAP43) and olfactory maker protein (OMP), which were the specific markers of olfactory sensory neuron, were detected by immunofluorescence antibody assay. The expression intensities were compared by Chi-square test of four-grid table data. Results: aMSCs were successively isolated and cultured from human adenoid tissues. P0 cells generation had good adhesion and proliferation performance. P2 cells were basically purified. P5 cells expressed CD73 and CD90 with the purity of 99.3% and 99.75% respectively, without CD45 expression. P5 cells had a good ability of osteogenic differentiation and adipogenic differentiation. Neuron-like morphology and expression of β-tubulin 3 were found in differentiated cells after induced by RA, SHH, or bFGF, respectively. An induction of expression of GAP43 was found in differentiated cells of bFGF+SHH group and RA+SHH+bFGF group, without expression of OMP of each group. The intensity of GAP43 expression of RA+SHH+bFGF group was stronger than that of bFGF+SHH group (χ²=17.48, P<0.005). Conclusions: aMSCs can be cultured from human adenoid tissues, with the stably passaged and good differentiation ability. As a new population of mesenchymal stem cells, aMSCs have the neuroregenerative properties and could differentiate into immature olfactory sensory neurons under the induction of RA+SHH+bFGF in vitro.
Child ; Humans ; Hedgehog Proteins ; Olfactory Receptor Neurons ; Tubulin ; Adenoids ; Osteogenesis ; Cell Differentiation