Neuroscience letters
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Neuroscience letters · Feb 2015
Meta AnalysisVoxelwise meta-analysis of gray matter anomalies in Parkinson variant of multiple system atrophy and Parkinson's disease using anatomic likelihood estimation.
Numerous voxel-based morphometry (VBM) studies on gray matter (GM) in patients with the Parkinson variant of multiple system atrophy (MSA-P) and Parkinson's disease (PD) have been separately conducted. Identifying the different neuroanatomical changes in GM between MSA-P and PD through meta-analysis may aid the differential diagnosis of MSA-P and PD. A systematic review of VBM studies on patients with MSA-P and PD compared to healthy controls (HC) from the PubMed and Embase databases between January 1995 and June 2014 was conducted. ⋯ For patients with disease duration within 5 years, compared with PD, the decrease in GMV focused on the bilateral putamen and claustrum in MSA-P. In contrast, for patients with disease duration within 3 years, no significant GMV difference was found between MSA-P and PD. Our meta-analysis indicated that the atrophy of bilateral putamen or claustrum is not a neuroanatomical marker for distinguishing MSA-P from PD during the early stage by using the VBM method.
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Neuroscience letters · Feb 2015
Microglial P2X₇ receptor in the hypothalamic paraventricular nuclei contributes to sympathoexcitatory responses in acute myocardial infarction rat.
Several pieces of evidence indicate that the microglial P2X7 receptor (P2X7R) regulate cardiovascular activities. We explored the possible roles of microglial P2X7R in the PVN mediated sympathoexcitatory responses in acute myocardial infarction (AMI) rat. Sprague-Dawley rats underwent coronary artery ligation to induce AMI. ⋯ Third, microinjected P2X7-siRNA also suppressed the up-regulation of P2X7R, oxytocin and vasopressin in the PVN of AMI rats. Fourth, P2X7-siRNA and BBG also attenuated the renal sympathetic nerve activity (RSNA) in the AMI rats. Our results indicate that microglial P2X7R activation in PVN mediating the production of proinflammatory cytokines that activate oxytocinergic and vasopressinergic neuron, which augmented the RSNA in the AMI rat.
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Neuroscience letters · Feb 2015
Intrathecal nefopam-induced antinociception through activation of descending serotonergic projections involving spinal 5-HT7 but not 5-HT3 receptors.
We examined the involvement of spinal 5-HT(5-hydroxytryptamine) receptor 3(5-HT3R) and 7(5-HT7R) as well as the overall role of descending serotonergic projections in the analgesic effects of intrathecal(i.t.) nefopam for two rat models of formalin and paw incision test. I.t. nefopam produced an antinociceptive effect in a dose-dependent manner in both tests. Lesioning the spinal serotonergic projections using i.t. 5,7-dihydroxytryptamine(5,7-DHT) did not influence the intensity of allodynia in the paw incision test, but i.t. 5,7-DHT abolished the effect of nefopam. ⋯ Antagonism study showed that i.t. 5-HT7R antagonist, SB269970 significantly blocked the antinociceptive effect of nefopam in both tests, but i.t. 5-HT3R antagonist, ondansetron has no influence on the effect of nefopam. The present study demonstrates that descending spinal serotonergic projections play a vital role in antinociceptive effect of i.t. nefopam in the paw incision test, but indeterminate in the formalin test. In both tests, the antinociceptive effect of i.t. nefopam involves the spinal 5-HT7R, but not 5-HT3R.
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Neuroscience letters · Feb 2015
Modulation of glutamatergic transmission by presynaptic N-methyl-D-aspartate mechanisms in second-order neurons of the rat nucleus tractus solitarius.
The present study investigated the physiological function of presynaptic N-methyl-d aspartate (NMDA) mechanisms in glutamatergic transmission in the rat nucleus tractus solitarius (NTS). Membrane currents were recorded from the NTS second-order neurons by using whole-cell patch pipettes including MK-801 to block postsynaptic NMDA receptors. All experiments were performed under blockade of inhibitory synaptic transmission. ⋯ D-AP5 decreased the mEPSC frequency without effect on the amplitude in 6/18 (33%) of neurons. This study demonstrated that (1) NMDA receptors were presynaptically distributed in a subset of NTS second-order neurons and that (2) the presynaptic NMDA receptors played an inhibitory role in TS-mediated release of glutamate and a facilitatory role in spontaneous release of glutamate. The present results suggest that the activation of presynaptic NMDA receptors modulates glutamatergic transmissions in the rat NTS second-order neurons.