Neuroscience
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Cerebral venous sinus thrombosis (CVST) is a rare but life-threatening disease and an animal model for in-depth study of CVST is needed. This study aimed to develop a rat model suitable for studying clinically relevant aspects of CVST and investigating its dynamic pathophysiological changes during a 7-day period. ⋯ In this study, we describe a rat model that produces clinically relevant pathophysiology and pathology that will facilitate evaluation of therapeutic regimens for CVST. Furthermore, our results indicate a period of optimal clinical intervention for patients with CVST, which may reduce the probability of dependency and death.
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Bisabolol is a plant-derived monocyclic sesquiterpene alcohol with antinociceptive and antiinflammatory actions. However, molecular targets mediating these effects of bisabolol are poorly understood. In this study, using a two-electrode voltage-clamp and patch-clamp techniques and live cellular calcium imaging, we have investigated the effect of bisabolol on the function of human α7 subunit of nicotinic acetylcholine receptor (nAChR) in Xenopus oocytes, interneurons of rat hippocampal slices. ⋯ Furthermore, the specific binding of [(125)I] α-bungarotoxin was not attenuated by bisabolol. Choline-induced currents in CA1 interneurons of rat hippocampal slices were also inhibited with IC50 of 4.6 μM. Collectively, our results suggest that bisabolol directly inhibits α7-nAChRs via a binding site on the receptor channel.
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Infection by the neurotropic agent Toxoplasma gondii alters rodent behavior and can result in neuropsychiatric symptoms in humans. Little is understood regarding the effects of infection on host neural processes but alterations to dopaminergic neurotransmission are implicated. We have previously reported elevated levels of dopamine (DA) in infected dopaminergic cells however the involvement of the host enzymes and fate of the produced DA were not defined. ⋯ In contrast, cellular DA packaging appeared unchanged in single-cell microamperometry experiments and only a fraction of the increased DA was accessible to high potassium-induced release. This study provides some understanding of how this parasite produces elevated DA within dopaminergic cells without the toxic ramifications of free cytosolic DA. The mechanism for synthesis and packaging of DA by T. gondii-infected dopaminergic cells may have important implications for the effects of chronic T. gondii infection on humans and animals.
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The insular cortex in rat is a longitudinal strip that runs along the rostral half of the rhinal fissure. The previous studies showed connections between the posterior insular cortex (PIC) and some major cardiovascular centers. Based on the stimulation site, electrical or chemical stimulation of the PIC induced an increase or a decrease in blood pressure (BP) and heart rate (HR). ⋯ In conclusion, there were five types of cardiovascular and five types of single-unit responses, to Glut microinjection into PIC, from which three types were correlated. The left side of the PIC is involved more in the cardiovascular functions. These data along with the fact that most recorded neurons responded to baroreceptor activation, might imply the presence of feedback systems in the PIC, producing irregularity in BP and HR.
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Learning and memory impairment is one of the most challenging complications of cirrhosis and present treatments are unsatisfactory. The exact mechanism of cirrhosis cognitive dysfunction is unknown. Pregnenolone sulfate (PREGS) is an excitatory neurosteroid that acts as a N-methyl-D-aspartate (NMDA) receptor agonist and GABAA receptor antagonist. ⋯ PREGS effects on memory of cirrhotic rats were antagonized by DAP5. RT-PCR findings have shown that hippocampal relative BDNF mRNA expression was up-regulated in PREGS-treated groups in comparison with the BDL group (P<0.001). Our findings suggest that PREGS has a memory-enhancing effect in cirrhosis memory deficit in acute therapy and this effect may be through NMDA (glutamate) receptor involvement and BDNF mRNA expression.