Neuroscience research
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Neuroscience research · Sep 2013
Expression variations of chromogranin A and α1,2,4 GABA(A)Rs in discrete limbic and brainstem areas rescue cardiovascular alterations.
Recent interferences of hemodynamic functions via modified brain neuronal mechanisms have proven to be major causes of dementia and sleeping disorders. In this work, cerebral expression differences of the neuroactive vesicular chromogranin A (CgA) and distinct α GABA(A)R subunits were detected in the facultative hibernating hamster. In particular, damaged neuronal fields of hypotensive torpor (TORP) state were correlated to elevated CgA and GABA(A)R α1, α4 mRNA levels in the paraventricular hypothalamic nucleus (PVN), central amygdalar nucleus (CeA) plus solitary tractus nucleus (NTS). ⋯ This state also provided increased α2-containing sites in amygdala, hippocampal and NTS neurons together with elevated α4-containing receptors in the periventricular hypothalamic nucleus (Pe). Interestingly in our hibernating model, CgA appeared to preferentially feature inhibitory neurosignals as indicated by preliminary perfusion of amygdalar sites with its highly specific antihypertensive derived peptide (catestatin) promoting GABA-dependent sIPSCs. Overall, evident neuronal damages plus altered expression capacities of CgA and α1-, α2-, α4-GABA(A)Rs in CeA, Pe, PVN as well as NTS during both hibernating states corroborate for the first time key molecular switching events guaranteeing useful cardiovascular rescuing abilities of neurodegenerative disorders.
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Neuroscience research · Aug 2013
Transcranial direct current stimulation changes human endowment effect.
To test whether the right inferior frontal gyrus (IFG) plays role in the endowment effect, we investigated the effects of transcranial direct current stimulation (tDCS) of the right IFG on the willingness to accept/willingness to pay (WTA/WTP) discrepancy. Twelve healthy subjects underwent anodal, cathodal and sham tDCS on separate days. Stimulation was applied over the right IFG for 20min at 2mA. ⋯ The results showed that the WTA/WTP ratio after anodal tDCS was significantly higher than that after cathodal one. In addition, we found that the reaction time during the cathodal tDCS condition was significantly longer compared to those during anodal or sham tDCS conditions. Our findings suggest the functional relevance of the right IFG for producing endowment effect.
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Neuroscience research · Aug 2013
Effect of treadmill exercise on the BDNF-mediated pathway in the hippocampus of stressed rats.
A growing body of evidence suggests that exercise enhances hippocampal plasticity and function through BDNF up-regulation, which is potentiated by antidepressant treatment. However, little is known about the molecular mechanisms mediating the effect of exercise. The present study investigated the effect of treadmill exercise on PI3K/Akt signaling, which mediates synaptic plasticity in the hippocampus of stressed rats. ⋯ Treadmill exercise significantly attenuated the decreased expression of these proteins. Moreover, exercise significantly increased PI3K/Akt signaling in the absence of immobilization stress. These results suggest that treadmill exercise reverses stress-induced changes in the rat hippocampus via an increase in PI3K/Akt signaling and may induce a functional reconnection of hippocampal synapses that mediate antidepressant actions.
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Neuroscience research · Jul 2013
Blockade of interleukin-6 receptor suppresses inflammatory reaction and facilitates functional recovery following olfactory system injury.
We previously reported that anti-inflammatory treatment with steroids improves recovery outcome in an olfactory nerve injury model. Clinically, however, steroid administration is not recommended in the acute phase of head injury because of concerns regarding side effects and no evidence of its efficacy. Recently, it has been reported that interleukin-6 (IL-6) plays an important role in the inflammatory reaction. ⋯ MR16-1-injected animals showed significantly smaller areas of injury-associated tissue, fewer astrocytes and macrophages/microglia, and an increase in regenerating nerve fibers. Olfactory function assessments using both an olfactory avoidance behavioral test and evoked potential testing showed improved functional recovery in MR16-1-injected mice. These findings suggest that blockade of IL-6R could provide a new therapeutic strategy for the treatment of olfactory dysfunction following head injuries.
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Neuroscience research · May 2013
Extracellular cyclophilin A protects against blast-induced neuronal injury.
Blast-induced traumatic brain injury (TBI) and subsequent neurobehavioral deficits are major disabilities suffered by the military and civilian population worldwide. Rigorous scientific research is underway to understand the mechanism of blast TBI and thereby develop effective therapies for protection and treatment. By using an in vitro shock tube model of blast TBI with SH-SY5Y human neuroblastoma cells, we have demonstrated that blast exposure leads to neurobiological changes in an overpressure and time dependent manner. ⋯ In the present study, we demonstrate accumulation of CPA in the culture medium after repeated blast exposures supporting the notion of extracellular CPA mediated neuroprotection. Post-exposure treatment of the cells with purified recombinant CPA caused significant protection against blast-induced neuronal injury. Furthermore, repeated blast exposure was associated with phosphorylation of the proteins ERK1/2 and Bad suggesting a potential mechanism of neuroprotection by extracellular CPA and may aid in the development of targeted therapies for protection against blast-induced TBI.