Advances in morphological and functional studies on the paraventricular thalamic nucleus / 解剖学报

Paraventricular thalamic nucleus (PVT) is an essential component of the midline thalamus, which has been regarded as a transmit relay nucleus and an integrated center in multiple behaviors including wakefulness, food intake, addiction, reward and fear memory. PVT is predominantly populated with glutaminergic excitatory neurons expressing vesicular glutamate transporter-2 (VGluT2) but without GABAergic inhibitory neurons. Therefore, based on the paradox of its multiplexed roles in different behaviors and its comparatively simplex excitatory nature, more specific subclassification of excitatory PVT neurons is required in studies in this field. In the present review, morphological and electrophysiological characteristics, efferent and afferent connections, and morphological and functional distinctions in anterior subregion and posterior subregion of PVT are summarized. In addition, neural connections and neurochemical properties are used as subclassification criteria in PVT neurons. This review might explain the integrated role of PVT in different behaviors, which would be helpful for further studies on the PVT.

Adolescent stress increases depression-like behaviors and alters the excitatory-inhibitory balance in aged mice / 中华医学杂志(英文版)

Background@#Depression affects approximately 5% of elderly people and its etiology might be related to chronic stress exposure during neurodevelopmental periods. In this study, we examined the effects of adolescent chronic social stress in aged mice on depressive behaviors and the excitatory-inhibitory (E/I) balance in stress-sensitive regions of the brain.@*Methods@#Sixty-four adolescent, male C57BL/6 mice were randomly assigned to either the 7-week (from post-natal days 29 to 77) social instability stress (stress group, n = 32) or normal housing conditions (control group, n = 32). At 15 months of age, 16 mice were randomly selected from each group for a series of behavioral tests, including two depression-related tasks (the sucrose preference test and the tail suspension test). Three days following the last behavioral test, eight mice were randomly selected from each group for immunohistochemical analyses to measure the cell density of parvalbumin (PV+)- and calretinin (CR+)-positive gamma-aminobutyric-acid (GABA)ergic inhibitory inter-neurons, and the expression levels of vesicular transporters of glutamate-1 (VGluT1) and vesicular GABA transporter (VGAT) in three stress-sensitive regions of the brain (the medial pre-frontal cortex [mPFC], hippocampus, and amygdala).@*Results@#Behaviorally, compared with the control group, adolescent chronic stress increased depression-like behaviors as shown in decreased sucrose preference (54.96 ± 1.97% vs. 43.11 ± 2.85%, t(22) = 3.417, P = 0.003) and reduced latency to immobility in the tail suspension test (92.77 ± 25.08 s vs. 33.14 ± 5.95 s, t(25) = 2.394, P = 0.025), but did not affect anxiety-like behaviors and pre-pulse inhibition. At the neurobiologic level, adolescent stress down-regulated PV+, not CR+, inter-neuron density in the mPFC (F(1, 39) = 19.30, P < 0.001), and hippocampus (F(1, 42) = 5.823, P = 0.020) and altered the CR+, not PV+, inter-neuron density in the amygdala (F(1, 28) = 23.16, P < 0.001). The VGluT1/VGAT ratio was decreased in all three regions (all F > 10.09, all P < 0.004), which suggests stress-induced hypoexcitability in these regions.@*Conclusions@#Chronic stress during adolescence increased depression-like behaviors in aged mice, which may be associated with the E/I imbalance in stress-sensitive brain regions.

Thymosin Alpha-1 Inhibits Complete Freund's Adjuvant-Induced Pain and Production of Microglia-Mediated Pro-inflammatory Cytokines in Spinal Cord / 神经科学通报·英文版

Activation of inflammatory responses regulates the transmission of pain pathways through an integrated network in the peripheral and central nervous systems. The immunopotentiator thymosin alpha-1 (Tα1) has recently been reported to have anti-inflammatory and neuroprotective functions in rodents. However, how Tα1 affects inflammatory pain remains unclear. In the present study, intraperitoneal injection of Tα1 attenuated complete Freund's adjuvant (CFA)-induced pain hypersensitivity, and decreased the up-regulation of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in inflamed skin and the spinal cord. We found that CFA-induced peripheral inflammation evoked strong microglial activation, but the effect was reversed by Tα1. Notably, Tα1 reversed the CFA-induced up-regulation of vesicular glutamate transporter (VGLUT) and down-regulated the vesicular γ-aminobutyric acid transporter (VGAT) in the spinal cord. Taken together, these results suggest that Tα1 plays a therapeutic role in inflammatory pain and in the modulation of microglia-induced pro-inflammatory cytokine production in addition to mediation of VGLUT and VGAT expression in the spinal cord.

Vesicular Glutamate Transporter 1 (VGLUT1)- and VGLUT2-containing Terminals on the Rat Jaw-closing γ-Motoneurons

Currently, compared to jaw-closing (JC) α-motoneurons, the information on the distribution and morphology of glutamatergic synapses on the jaw-closing (JC) γ-motoneurons, which may help elucidate the mechanism of isometric contraction of the JC muscle, is very limited. This study investigated the distribution and ultrastructural features of vesicular glutamate transporter 1 (VGLUT1)- and VGLUT2-immunopositive (+) axon terminals (boutons) on JC γ-motoneurons by retrograde tracing with horseradish peroxidase, electron microscopic immunocytochemistry, and quantitative analysis. About 35% of the boutons on identified JC γ-motoneurons were VGLUT+, and of those, 99% were VGLUT2+. The fraction of VGLUT1+ boutons of all boutons and the percentage of membrane of JC γ-motoneurons covered by these boutons were significantly lower than those for the JC α-motoneurons, revealed in our previous work. The bouton volume, mitochondrial volume, and active zone area of the VGLUT2+ boutons on the JC γ-motoneurons were uniformly small. These findings suggest that the JC γ-motoneurons, in contrast to the JC α-motoneurons, receive generally weak glutamatergic synaptic input almost exclusively from VGLUT2+ premotoneurons that form direct synapse with motoneurons.

Electroacupuncture Alleviates Motor Symptoms and Up-Regulates Vesicular Glutamatergic Transporter 1 Expression in the Subthalamic Nucleus in a Unilateral 6-Hydroxydopamine-Lesioned Hemi-Parkinsonian Rat Model / 神经科学通报·英文版

Previous studies have shown that electroacupuncture (EA) promotes recovery of motor function in Parkinson's disease (PD). However the mechanisms are not completely understood. Clinically, the subthalamic nucleus (STN) is a critical target for deep brain stimulation treatment of PD, and vesicular glutamate transporter 1 (VGluT1) plays an important role in the modulation of glutamate in the STN derived from the cortex. In this study, a 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD was treated with 100 Hz EA for 4 weeks. Immunohistochemical analysis of tyrosine hydroxylase (TH) showed that EA treatment had no effect on TH expression in the ipsilateral striatum or substantia nigra pars compacta, though it alleviated several of the parkinsonian motor symptoms. Compared with the hemi-parkinsonian rats without EA treatment, the 100 Hz EA treatment significantly decreased apomorphine-induced rotation and increased the latency in the Rotarod test. Notably, the EA treatment reversed the 6-OHDA-induced down-regulation of VGluT1 in the STN. The results demonstrated that EA alleviated motor symptoms and up-regulated VGluT1 in the ipsilateral STN of hemi-parkinsonian rats, suggesting that up-regulation of VGluT1 in the STN may be related to the effects of EA on parkinsonian motor symptoms via restoration of function in the cortico-STN pathway.

Expression of GABA and glutamate vesicular transporter in depressed mice / 重庆医学

Objective To study the expression of vesicular GABA transporter and vesicular glutamate transporter 1 in de‐pression .Methods Mice was divided into control group and defeat group stochastically .By social defeat model and social avoidance , the defeat group was divided into two groups:susceptible group and unsusceptible group .Synaptic proteins were extracted respec‐tively from the 3 groups .We detected the expression abundance of VGAT and VGLUT1 by Western blot .Results Compared with the control group ,in susceptible group ,the residence time in the contact area was significantly reduced ,and the residence time in the corner area was significantly increased ,with statistical difference(P0 .05) .In the striatum ,although the expression levels of VGAT and VGLUT1 were increased in susceptible group ,but in unsusceptible group ,the expression of these proteins also increased significantly .Conclusion The prefrontal cortex and hippo‐campus excitability and inhibitory vesicle transport were changed in depression ,which may relate to the transcription disorder .

Inhibitors of vesicular glutamate transporter: Research advances / 国际药学研究杂志

Vesicular glutamate transporter (VGLUT), located on the vesicular membrane, is a highly specific marker of glut- amatergic neurons. VGLUT selectively transports glutamate in the cytoplasm into vesicles. VGLUT1, VGLUT2 and VGLUT3 are three subtypes of VGLUT. The VGLUT can influence the glutamatergic synaptic transmission through mediating sequestration, storage and release of glutamate. The number and activity of VGLUT can change the level of glutamate in synapse cleft through mediating sequestration, storage and release of glutamate, then influence the glutamatergic synaptic transmission. To improve this pathological situation and maintain glutamate at the physiologically relevant concentration, VGLUT inhibition is required. Several classes of competitive VGLUT inhibitors have emerged including azo dyes, substituted quinolines, fatty acids and alkaloids. This article provides a brief review on the structure and function of these potential VGLUT inhibitors.

Inhibitors of vesicular glutamate transporter:research advances / 国际药学研究杂志

Vesicular glutamate transporter(VGLUT), located on the vesicular membrane, is a highly specific marker of glut-amatergic neurons. VGLUT selectively transports glutamate in the cytoplasm into vesicles. VGLUT1, VGLUT2 and VGLUT3 are three subtypes of VGLUT. The VGLUT can influence the glutamatergic synaptic transmission through mediating sequestration, storage and release of glutamate. The number and activity of VGLUT can change the level of glutamate in synapse cleft through mediating sequestration,storage and release of glutamate,then influence the glutamatergic synaptic transmission. To improve this pathological situation and maintain glutamate at the physiologically relevant concentration, VGLUT inhibition is required. Several classes of competitive VGLUT inhibitors have emerged including azo dyes, substituted quinolines, fatty acids and alkaloids. This article provides a brief review on the structure and function of these potential VGLUT inhibitors.

C/EBPα is involved in transcriptional regulation of mVGLUT2 gene expression / 中国病理生理杂志

AIM: The main purpose of this study is to investigate the regulatory role of C/EBPα in mouse vesicular glutamate transporter 2(mVGLUT2) gene expression. METHODS: The promoter region of mVGLUT2 was cloned to PGL3-basic vector. Site-direction mutation was used to identify the CCAAT-enhancer-binding protein α(C/EBPα) binding site. The promoter activity was observed by luciferase system. The binding between C/EBPα protein and mVGLTU2 promoter region was determined by EMSA. The C/EBPα gene expression was inhibited by its specific siRNA. RESULTS: mVGLUT2 promoter activity decreased about 50% after mutation of C/EBPα binding site. EMSA showed that C/EBPα protein bound onto mVGLUT2 promoter region. Meanwhile, when C/EBPα gene expression was inhibited by its specific siRNA, mVGLUT2 promoter activity, mRNA level and protein level were decreased about 60%, 40% and 45%, respectively. CONCLUSION: C/EBPα is involved in the regulation of mVGLUT2 gene expression.

An experimental study of neuronal activation through body-weight-supposed treadmill training after spinal cord injury using laser confocal microscopy / 中华物理医学与康复杂志

Objective To investigate the effects of locomotor training on improving locomotor function after spinal cord injury(SCI)and the mechanism of spinal cord plasticity.Methods A model of complete thoracic cord transection was established using 84 adult female rats divided into sham,SCI and treadmill training(BWSTT) groups.The hind limb locomotor function of all the rats was evaluated.The fluorescence intensities due to (EphA4),vesicular glutamate transporter 2(VGluT2)and EphA4/VGluT2 double-positive neurons in the ventromedial area of the anterior horn of the lumbar COrd were detected using immunofluorescence double labeling and laser confocal microscopy.Results The rats in the BWSTT group showed better functional recovery in their hind limbs than those in the SCI group.BWSTT was correlated with markedly increased EphA4.VGIuT2 and EphA4/VGluT2 intensities in the ventromedial area.Conclusion BWSTT improves hind limb locomotor function in rats with thoracic cord transections by elevating the expression of EphA4/VGluT2,promoting neuronal plasticity in the lumbar anterior horn.

ASSOCIATION OF VESTICULAR GLUTAMATE TRANSPORTERS-AND 5-HT-LIKE IMMUNOREACTIVE VARICOSITIES WITH MESENCEPHALIC TRIGEMINAL NUCLEUS NEURONS IN THE RAT / 神经解剖学杂志

The possible relationship of vesicular glutamate transporters ( VGluT1 and VGluT2 ) - and 5-HT-like immunoreactive (LI) terminals with mesencephalic trigeminal nucleus (Vme) neurons in the rat was examined by using triple-immunofluorescence histochemistry and double-labeled electron microscopic immunohistochemistry. Under confocal laser-scanning microscope, many neuronal cell bodies of Vme showed phosphate-activated glutaminase (PAG) -LI and the vast majority of them were large pseudounipolar neurons. A considerable number of VGluT1 -LI and VGluT2-LI terminals were widely distributed in Vme, the density of VGluT2-LI terminals was higher than that of VGluT1-LI. 5-HT-LI axonal varicosities had dense distribution in Vme, and some 5-HT-LI terminals also showed immunoreactivity for VGluT2. Some VGluT1-LI, VGluT2-LI, 5-HT-LI and VGluT2/5-HT-LI terminals were frequently observed in close apposition to the cell bodies of Vme neurons showing PAG-LI. Under electron microscope, VGluT1/VGluT2-LI and 5-HT-LI were visualized with silver grains and peroxidase products, respectively. Some terminals in Vme showed both VGluT2- and 5-HT-LI, these dual labeled varicosities usually made asymmetric contact with Vme neurons. Synaptic terminals that showed VGluT1-LI was also observed, but no coexpression of VGluT1 and 5-HT was found in Vme. The present results suggest that in the transmission of the proprioceptive sensory information from the orofacial regions to the higher center, glutamate and 5-HT may play important roles on the regulation of Vme neurons through complicated integration.

CONNECTIONS BET WEEN VESICULAR GLUTAMATE TRANSPORTERS-,GAD-LIKE IMMUNOREACTIVE TERMINALS AND GABA_A RECEPTOR ?3 SUBUNIT- LIKE POSITIVE NEURONS IN MESENCEPHALIC TRIGEMINAL NUCLEUS OF THE RAT / 解剖学报

Objective To observe the association of vesicular glutamate transporter of typeⅠ (VGluT1 ) like immunoreactive(LI) ,the differentiation-associated Na+ dependent inorganic phosphate cotransporter(DNPI) LI and glutami cacid decarboxy lase(GAD) LI terminals with GABAA receptor ?3 subunit(GABAAR ?3) LI neurons in mesencephalic trige minal nucleus of the rat.Methods Triple immun of luorescencehis to chemical staining technique and confo call aser scanning micros copy were used.Results Alargenumber of neuronal cell bodies showed GABAA R?3 LI immunoreactivity atallrostrocaudal level softhe Vme ,and most of GABAAR ?3 LI cells were large (2 5 5 0 ?m)pseudouni polarneurons.The dense VGluT1 LI,DNPL LI and GAD LIterminal sdistri buted widelyin Vme ,some VGlu T1 DNPI LI and GAD LIterminals surrounded the somata of the GABAAR ?3 LI Vmeneurons ,and made close contacts with them .Conclusion Proprioceptive sensory signals from the or of acialregionmight be modulated at the level of the primary afferent cell bodies in the Vme both by glutamatergic and GABAergic axonal terminals from other brain areas,and the effect of GABAergic terminals might be mediated by post synaptical GABAA receptors .

C/EBP? is involved in transcriptional regulation of mVGLUT2 gene expression / 中国病理生理杂志

AIM:The main purpose of this study is to investigate the regulatory role of C/EBP? in mouse vesicular glutamate transporter 2(mVGLUT2) gene expression. METHODS:The promoter region of mVGLUT2 was cloned to PGL3-basic vector. Site-direction mutation was used to identify the CCAAT-enhancer-binding protein ?(C/EBP?) binding site. The promoter activity was observed by luciferase system. The binding between C/EBP? protein and mVGLTU2 promoter region was determined by EMSA. The C/EBP? gene expression was inhibited by its specific siRNA. RESULTS:mVGLUT2 promoter activity decreased about 50% after mutation of C/EBP? binding site. EMSA showed that C/EBP? protein bound onto mVGLUT2 promoter region. Meanwhile,when C/EBP? gene expression was inhibited by its specific siRNA,mVGLUT2 promoter activity,mRNA level and protein level were decreased about 60%,40% and 45%,respectively. CONCLUSION:C/EBP? is involved in the regulation of mVGLUT2 gene expression.

CHANGES OF EXPRESSION OF VESICULAR GLUTAMATE TRANSPORTER 1 IN THE RAT TRIGEMINAL COMPLEX AFTER MANDIBULAR NERVE TRANSECTION / 解剖学报

Objective The changes of VGluT1-like immunoreactivity(VGluT1-LI) in the trigeminal complex of the rat in different survival time after unilateral mandibular nerve transection were examined. Methods Immunocytochemical staining method and image analysis technique were performed. Results Many VGluT1-LI were observed in the trigeminal complex of the normal rat and were mainly distributed in the terminals.A weak decrease of VGIuT1-LI in the dorsal part of principal trigeminal nucleus(Vp) could be detected at the first week after unilateral transection of mandibular nerve(P