Tweety-Homolog 1 Facilitates Pain via Enhancement of Nociceptor Excitability and Spinal Synaptic Transmission / 神经科学通报·英文版

Tweety-homolog 1 (Ttyh1) is expressed in neural tissue and has been implicated in the generation of several brain diseases. However, its functional significance in pain processing is not understood. By disrupting the gene encoding Ttyh1, we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice, along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey (PAG) in the basal state. More importantly, the peripheral inflammation-evoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice. Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release. Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief. Thus, in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.

Construction and implementation of a new system for fundamentals and frontiers of brain science curriculum for medical graduates / 医学研究生学报

In order to adapt to the rapid development of brain science and cultivate high-level innovative brain science research talents, combined with the practical teaching experience in the Department of Neurobiology of Air Force Military Medical University in recent years, the article constructs a new system for fundamentals and frontiers of brain science curriculum, which integrates advanced teaching concepts, diverse teaching forms and flexible teaching modes, expecting this new curriculum system will lay a solid foundation for the cultivation of talents in brain science.

Spinal CCL2 Promotes Central Sensitization, Long-Term Potentiation, and Inflammatory Pain via CCR2: Further Insights into Molecular, Synaptic, and Cellular Mechanisms / 神经科学通报·英文版

Mounting evidence supports an important role of chemokines, produced by spinal cord astrocytes, in promoting central sensitization and chronic pain. In particular, CCL2 (C-C motif chemokine ligand 2) has been shown to enhance N-methyl-D-aspartate (NMDA)-induced currents in spinal outer lamina II (IIo) neurons. However, the exact molecular, synaptic, and cellular mechanisms by which CCL2 modulates central sensitization are still unclear. We found that spinal injection of the CCR2 antagonist RS504393 attenuated CCL2- and inflammation-induced hyperalgesia. Single-cell RT-PCR revealed CCR2 expression in excitatory vesicular glutamate transporter subtype 2-positive (VGLUT2) neurons. CCL2 increased NMDA-induced currents in CCR2/VGLUT2 neurons in lamina IIo; it also enhanced the synaptic NMDA currents evoked by dorsal root stimulation; and furthermore, it increased the total and synaptic NMDA currents in somatostatin-expressing excitatory neurons. Finally, intrathecal RS504393 reversed the long-term potentiation evoked in the spinal cord by C-fiber stimulation. Our findings suggest that CCL2 directly modulates synaptic plasticity in CCR2-expressing excitatory neurons in spinal lamina IIo, and this underlies the generation of central sensitization in pathological pain.

Antitumor effect of volatile oil from Sinapis Albae Semen on H22-bearing mice and its mechanism / 中草药

Objective: To investigate the antitumor effect of volatile oil from Sinapis Albae Semen (VOSAS) on H22-bearing mice and to determine the mechanism. Methods: To establish the H22 implanted hepatocellular carcinoma animal model which was used to analyze the effect of VOSAS on the growth of transplanted tumor. Mice were divided into five groups 24 h after modeling: model, cytoxan (CTX, 25 mg/kg) positive control, low-, mid-, and high-dose (20, 40, and 80 mg/kg) VOSAS groups. The mice were ip administered once daily for 10 d. Morphological changes in H22 solid tumor cells were observed by both Hematoxylin-eosin (HE) and acridine orange (AO) staining. The expression of Bax and Bcl-2 in the tumor tissue was determined using immunohistochemistry. Results: VOSAS could inhibit the tumor growth and extend the life span of H22-bearing mice (P < 0.01); and it could also raise the expression of Bax while suppress the expression of Bcl-2; the antitumor effect of VOSAS on H22-bearing mice demonstrated a good dose-effect relationship, but the high-dose group of the volatile oil has obvious toxicity and side effects on the mice. Conclusion: VOSAS could inhibit the growth of H22 tumor cells and the mechanism may be related to up-regulating the expression of Bax and down-regulating the expression of Bcl-2, and the induction of apoptosis.

GAD67-GFP expression and co-localization with bNOS in main olfactory bulb of GAD67-GFP knock-in mouse / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the distribution of GAD67 and the co-localization with bNOS in the main olfactory bulb of GAD67-GFP knock-in mouse.</p><p><b>METHODS</b>Polymerase chain reaction was applied to identify the genotype of GAD67-GFP knock-in mouse, the animals were sacrificed and frozen sections of olfactory bulb were prepared. The Nissl-staining was performed to show an framework of the neuron in the olfactory bulb. The distribution of GAD67 and co-localization with bNOS were detected by immunofluorescence technique.</p><p><b>RESULTS</b>The proportion of GAD67-positive cells among DAPI-positive cells were (42.98 ± 0.92)% in glomerular layer, (23.64 ± 0.84)% in mitral cell layer and (77.75 ± 0.84)% in granule cell layer; the bNOS-positive cells mainly existed in glomerular layer and mitral cell layer, very few in granule cell layer. No co-localization of GAD67 and bNOS in granule cell layer and mitral cell layer was found, but there was dispersed distribution in glomerular layer.</p><p><b>CONCLUSION</b>GAD67-positive neurons mainly appear in glomerular layer and granule cell layer, and the bNOS is mostly expressed in glomerular layer and mitral cell layer; while the co-localization of GAD67 and bNOS only occurs in glomerular layer of olfactory bulb.</p>

In-vivo and ex-vivo studies on region-specific remodeling of large elastic arteries due to simulated weightlessness and its prevention by gravity-based countermeasure / 生理学报

The present study was designed to test the hypothesis that a medium-term simulated microgravity can induce region-specific remodeling in large elastic arteries with their innermost smooth muscle (SM) layers being most profoundly affected. The second purpose was to examine whether these changes can be prevented by a simulated intermittent artificial gravity (IAG). The third purpose was to elucidate whether vascular local renin-angiotensin system (L-RAS) plays an important role in the regional vascular remodeling and its prevention by the gravity-based countermeasure. This study consisted of two interconnected series of in-vivo and ex-vivo experiments. In the in-vivo experiments, the tail-suspended, hindlimb unloaded rat model was used to simulate microgravity-induced cardiovascular deconditioning for 28 days (SUS group); and during the simulation period, another group was subjected to daily 1-hour dorso-ventral (-G(x)) gravitation provided by restoring to normal standing posture (S + D group). The activity of vascular L-RAS was evaluated by examining the gene and protein expression of angiotensinogen (Ao) and angiotensin II receptor type 1 (AT1R) in the arterial wall tissue. The results showed that SUS induced an increase in the media thickness of the common carotid artery due to hypertrophy of the four SM layers and a decrease in the total cross-sectional area of the nine SM layers of the abdominal aorta without significant change in its media thickness. And for both arteries, the most prominent changes were in the innermost SM layers. Immunohistochemistry and in situ hybridization revealed that SUS induced an up- and down-regulation of Ao and AT1R expression in the vessel wall of common carotid artery and abdominal aorta, respectively, which was further confirmed by Western blot analysis and real time PCR analysis. Daily 1-hour restoring to normal standing posture over 28 days fully prevented these remodeling and L-RAS changes in the large elastic arteries that might occur due to SUS alone. In the ex-vivo experiments, to elucidate the important role of transmural pressure in vascular regional remodeling and differential regulation of L-RAS activity, we established an organ culture system in which rat common carotid artery, held at in-vivo length, can be perfused and pressurized at varied flow and pressure for 7 days. In arteries perfused at a flow rate of 7.9 mL/min and pressurized at 150 mmHg, but not at 0 or 80 mmHg, for 3 days led to an augmentation of c-fibronectin (c-FN) expression, which was also more markedly expressed in the innermost SM layers, and an increase in Ang II production detected in the perfusion fluid. However, the enhanced c-FN expression and increased Ang II production that might occur due to a sustained high perfusion pressure alone were fully prevented by daily restoration to 0 or 80 mmHg for a short duration. These findings from in-vivo and ex-vivo experiments have provided evidence supporting our hypothesis that redistribution of transmural pressures might be the primary factor that initiates region-specific remodeling of arteries during microgravity and the mechanism of IAG is associated with an intermittent restoration of the transmural pressures to their normal distribution. And they also provide support to the hypothesis that L-RAS plays an important role in vascular adaptation to microgravity and its prevention by the IAG countermeasure.

The expression of PPTA and c-fos mRNA in dog caudal spinal trigeminal nucleus induced by traumatic occlusion / 中华口腔医学杂志

<p><b>OBJECTIVE</b>PPTA and c-fos mRNA expression were detected in dog caudalis subnucleus of trigeminal spinal tract nucleus (VC) induced by trauma occlusion in order to investigate orofacial pain mechanism.</p><p><b>METHODS</b>The occlusal surface of the first and second maxillary right molars in 15 dogs were unilaterally raised 1.5 mm with casting Ni-Cr inlay which were fixed in Class I hole. On days 3, 7, 14, 30 and 60 after teeth operation, the VC of right and left sides were removed. PPTA and c-fos mRNAs were detected in experimental and control groups with reverse transcription-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>(1) The basal levels of PPTA and c-fos mRNAs were extremely low and poorly detectable in VC in control animals. (2) The expression of PPTA mRNA in VC of traumatic side was up regulated from 3 days after inlay was fixed in molar and reached peak level during 14 to 30 days and then down-regulated gradually and no significant difference was noted between 60 days group and control group. (3) c-fos mRNA expression was more intense during 3 to 7 days compared with the control group but undetectable in the other experimental period. (4) Both PPTA and c-fos mRNAs expression in VC of trauma occlusal side were more intense than that in the contralateral side.</p><p><b>CONCLUSIONS</b>The present results show that both PPTA and c-fos mRNA expression are elevated in dog's VC induced by traumatic occlusion. The primary afferent terminal of orofacial area is sensitized, which suggest one kind of mechanism of orofacial pain in the condition of traumatic occlusion.</p>

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>

Change of expression of P-selectin in avulsion-injured vessels / 中华整形外科杂志

<p><b>OBJECTIVE</b>To determine the change of P-selectin in avulsion-injured vessels.</p><p><b>METHODS</b>Different stretch forces of 60, 70, 80 and 90 g were applied to a vascular injury model. The expression changes of P-selectin were evaluated by RT-PCR.</p><p><b>RESULTS</b>The expression of P-selection mRNA in the injured vessels increased with the stretch force.</p><p><b>CONCLUSION</b>The result associated with our previous study indicated that P-selectin may be involved in thrombosis.</p>