Trends in neuroanatomical research / 解剖学报

The basic structure of the nervous system is neurons and the connections formed by nerve fibers. Identifying different types of neurons in different parts of the nervous system, revealing the efferent and afferent nerve fibers they constitute, and elucidating the neuroactive substances and receptors involved, provide the basis for the regulation of neuronal activity and the uncovering of how the nervous system works. It is also the goal of neuroanatomy research. The rapid development of modern science and technology and interdisciplinary penetration require us to conduct in-depth neuroanatomy studies on specific neural pathways composed of specific types of neurons using specific neuroactive substances for specific neural functions. This also provides a good opportunity for us to clarify the structure of nervous system and analyze its working principle from macroscopic, mesoscopic and microscopic levels.

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.

Molecular mechanism underlying vascular development in the brain / 解剖学报

As the pipelines of nutrient and oxygen in the brain, cerebral vessels play an important role in the development and normal function of the brain. The development of the cerebrovascular system is divided into two processes, primitive vasculogenesis and angiogenesis. In this review, we summarize the roles, regulation mechanisms, as well as the interactions of the essential signaling molecules, such as the family members of vascular endothelial growth factor（VEGF）, neuropillin, Wnt, Notch, Hedgehog, in the vessel development, aiming to provide a reference for the basic and clinical investigation and the prevention and treatment of vascular diseases. Reset.

Anterior Cingulate Cortex Mediates Hyperalgesia and Anxiety Induced by Chronic Pancreatitis in Rats / 神经科学通报·英文版

Central sensitization is essential in maintaining chronic pain induced by chronic pancreatitis (CP), but cortical modulation of painful CP remains elusive. Here, we examined the role of the anterior cingulate cortex (ACC) in the pathogenesis of abdominal hyperalgesia in a rat model of CP induced by intraductal administration of trinitrobenzene sulfonic acid (TNBS). TNBS treatment resulted in long-term abdominal hyperalgesia and anxiety in rats. Morphological data indicated that painful CP induced a significant increase in FOS-expressing neurons in the nucleus tractus solitarii (NTS) and ACC, and some FOS-expressing neurons in the NTS projected to the ACC. In addition, a larger portion of ascending fibers from the NTS innervated pyramidal neurons, the neural subpopulation primarily expressing FOS under the condition of painful CP, rather than GABAergic neurons within the ACC. CP rats showed increased expression of vesicular glutamate transporter 1, and increased membrane trafficking and phosphorylation of the N-methyl-D-aspartate receptor (NMDAR) subunit NR2B and the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) subunit GluR1 within the ACC. Microinjection of NMDAR and AMPAR antagonists into the ACC to block excitatory synaptic transmission significantly attenuated abdominal hyperalgesia in CP rats, which was similar to the analgesic effect of endomorphins injected into the ACC. Specifically inhibiting the excitability of ACC pyramidal cells via chemogenetics reduced both hyperalgesia and comorbid anxiety, whereas activating these neurons via optogenetics failed to aggravate hyperalgesia and anxiety in CP rats. Taken together, these findings provide neurocircuit, biochemical, and behavioral evidence for involvement of the ACC in hyperalgesia and anxiety in CP rats, as well as novel insights into the cortical modulation of painful CP, and highlights the ACC as a potential target for neuromodulatory interventions in the treatment of painful CP.

An HPLC method for determination of ebracteolatain A content in the root of Euphorbia fischeriana Steud and Euphorbia ebracteolata Hayata / 第二军医大学学报

Objective To establish a method for determination of ebracteolatain A content in the root of traditional Chinese medicine white Langdu, including Euphorbia fischeriana Steud and Euphorbia ebracteolata Hayata. Methods An HPLC-DAD method was created for determination at the following condition:the column was Agilent Zorbax SB-C18 (4.6 mm×150 mm, 5 μm);mobile phase was acetonitrile:0.1% formic acid in water=55:45(V:V), isocratic elution, the flow rate was 1.0 mL·min-1, the temperature of column was 25°C, the detection wavelength was set at 290 nm, the injection volume was 20 μL, and the running time was 20 min. Results Ebracteolatain A was separated from the interference in the baseline, and the linear range was 4.545-227.3 μg·mL-1, with the linear correlation being 0.9999 for ebracteolatain A. The result of intra-day and inter-day precisions were both within 2%(n=3), and the average recovery was (99.14±3.4)%(n=6). The content of ebracteolatain A in two batches of Euphorbia fischeriana Steud and Euphorbia ebracteolata Hayata were (56.73±1.09) μg/g, (18.98±2.11) μg/g and (235.2±2.4) μg/g (n=6), respectively. Conclusion The present method is simple, rapid, accurate and convenient for determination of ebracteolatain A in the root of traditional Chinese medicine white Langdu.

Inhibition of gamma-aminobutyric acid receptor-gated chloride currents by noradrenaline in rat spiral ganglion neuron / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the pharmacological modulatory properties of noradrenaline in the rat spiral ganglion neuron.</p><p><b>METHODS</b>Nystatin perforated patch recording technique under voltage-clamp conditions was used to record the modulatory effect of noradrenaline on the current evoked by gamma-amino butyric acid (GABA) in the spiral ganglion neuron.</p><p><b>RESULTS</b>The reversal potential of the GABA response was about (- 0.78 +/- 0.05) mV (n = 8), which was almost identical to the theoretical Cl- equilibrium potential. At the holding potential of -50 mV, GABA evoked inward current (I(GABA)) over the concentration range of 0.3 to 1 micromol/L. The EC50 and Hill coefficient for GABA were (5.2 +/- 0.5) micromol/L and 1.03 (n = 26). The I(GABA) was suppressed by bicuculline, the selective GABA-A receptor antagonist, and the chloride currents evoked by GABA was inhibited by noradrenaline.</p><p><b>CONCLUSIONS</b>The result indicates that noradrenaline depressed GABA-A receptor-gated chloride currents, which may contribute to the modulatory effect of sympathetic system on auditory transmission.</p>

Technique of rat cochlea slicing and study of rat spiral ganglion neurons by infrared visual slice patch clamp method / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To establishing the cochlea slice technique and infrared visual slice patch clamp method in order to observe the electrophysiological characteristics of rat spiral ganglion neurons (SGN) METHODS: SD rats were divided into three groups according to postnatal days old (0-2 d, 3-6 d and 7-14 d). Making slice of SD rat cochlear quickly, using infrared differential interference contrast (IR-DIC) technique, together with slice patch clamp, the electrophysiological characteristics of rat spiral ganglion neurons were observed, and factors which affected the quality of cochlear slice and recording of patch clamp were analyzed.</p><p><b>RESULTS</b>The success rate of 3-6 days SD was the highest, and 2-4 pieces of slice could be made from each cochlea. Cochlea connecting with partial skull and integrity of cochlear hull were the key for making slice, and the angle of modiolus axis should be adjusted to be parallel to the knife and the preparing time should be shorter. The SGN cell of good condition could be easily found and the seal test became easier with the help of infrared visual slice patch clamp method. The rest membrane potential was (-45.6 +/- 5.3) mV (x +/- s, n=52) and the current of Na+ and K+ could be activated.</p><p><b>CONCLUSIONS</b>Cochlear slice technique can retain structural integrity, cell viability and their association in cochlea, which suggest that this technique provides carrier for electrophysiological study of rat spiral ganglion neurons, and patch clamp with infrared videomicroscopy method can be used to make direct real-time observation in electrophysiological experiments of SGN, which can provide important technique support and reference for deep study of electrophysiological characteristics of SGN and auditory neurotransmission in cochlea.</p>

Localization of vesicular glutamate transporters in the peripheral vestibular system of rat / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To examine the vesicular glutamate transporters (VGluTs: VGluT1-VGluT3) in the peripheral vestibular system.</p><p><b>METHODS</b>The vestibular structures, including Scarpa's ganglion (vestibular ganglion, VG), maculae of utricle and saccule, and ampullary cristae, from normal Sprague-Dawley rats were processed immunohistochemically for VGluTs, by avidin-biotinylated peroxidase complex method, with 3-3'-diaminobenzidine (DAB) as chromogen.</p><p><b>RESULTS</b>(1) VGluT1 was localized to partial neurons of VG and to the putative primary afferent fibers innervating vestibular end-organs. (2) Intense VGluT3 immunoreactivity was detected in large number of sensory epithelia cells, and weak labeling of VGluT3-positive afferent fibers was in the maculae and ampullary cristae. (3) No or very weak VGluT2 immunoreactivity was observed in the VG and acoustic maculae.</p><p><b>CONCLUSION</b>These results provide the morphological support that glutamate exists in the peripheral vestibular system, and it may play an important role in the centripetal vestibular transmission.</p>

Vesicular glutamate transporter-immunoreactivities in the vestibular nuclear complex of rat / 神经科学通报·英文版

Objective Aims to delineate the distribution profile of three isoforms of vesicular glutamate transporter (VGluT), viz. VGluT1-3, and their cellular localization within vestibular nuclear complex (VNC). Methods Brain sections from normal Sprague-Dawley rats were processed immunohistochemically for VGluT detection, employing avidin-biotinylated peroxidase complex method with 3-3'-diaminobenzidine (DAB) as chromogen. Results The whole VNC expressed all of the three transporters that were observed to be localized to the fiber endings. Compared with VGluT1 and VGluT3, VGluT2 demonstrated a relatively homogeneous distribution, with much higher density in VNC. VGluT3 displayed the highest density in lateral vestibular nucleus and group X, contrasting with the sparse immunostained puncta within vestibular medial and inferior nuclei. Conclusion Glutamtatergic pathways participate in the processing of vestibular signals within VNC mainly through the re-uptake of glutamate into synaptic vesicles by VGluT1 and 2, whereas VGluT3 may play a similar role mainly in areas other than medial and inferior nuclei of VNC.

Co-existence of calcium-binding proteins and gamma-aminobutyric acid or glycine in neurons of the rat medullary dorsal horn / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>We investigated the co-expression of calbindin-D28k (CB), calretinin (CR) and parvalbumin (PV, a combination of the three is referred to as CaBPs) with gamma-aminobutyric acid (GABA) or glycine in neurons of the rat medullary dorsal horn (MDH).</p><p><b>METHODS</b>Immunofluorescence histochemical double-staining for CaBPs and GABA or glycine was performed on the sections from rat MDH.</p><p><b>RESULTS</b>CB-, CR-, PV-, GABA- and glycine-like immunoreactive (LI) neurons were differentially observed in all layers of the MDH, but particularly in lamina II. Neurons that exhibited immunoreactivity for both CaBPs and GABA or glycine were also observed mainly in lamina II. A few of them were found in laminae I and III. The percentages of neurons which co-expressed CB/GABA or CB/glycine out of the total numbers of CB- and GABA-LI neurons or CB- and glycine-LI neurons were 5.3% and 12.1% or 4.1% and 10.0%, respectively. The ratios of CR/GABA or CR/glycine co-existing neurons out of the total numbers of CR- and GABA-LI neurons or CR- and glycine-LI neurons were 5.8% and 7.6% or 4.4% and 7.1%, respectively. The rates of PV/GABA or PV/glycine co-localized neurons out of the total numbers of PV- and GABA-LI neurons or PV- and glycine-LI neurons were 11.1% and 5.1% or 9.9% and 5.1%, respectively.</p><p><b>CONCLUSION</b>The results indicate that some neurons in the MDH contain both CaBPs and GABA or glycine.</p>