Neuroscience
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Prenatal exposure to ethanol has been shown to increase the risk of anxiety in offspring. Here, we tested the effect of prenatal ethanol exposure on adult male mandarin voles (Microtus mandarinus). We examined anxiety-like behavior in the open field and elevated plus-maze tests in males exposed to ethanol prenatally. ⋯ Serum T was lower in the ethanol group, and the AR-IR number in the bed nucleus of the stria terminalis (BNST), medial preoptic area (mPOA) and medial amygdaloid nucleus (MeA) was significantly lower. The number of AVP-IRs in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the ethanol group was higher than that of the control groups. Our findings suggest that prenatal ethanol exposure may lead to reduced serum T levels, decreased AR and increased AVP in the CNS and result in the development of anxiety-like behaviors.
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The suprachiasmatic nucleus (SCN) is typically considered our autonomous clock synchronizing behavior with physiological parameters such as blood pressure (BP), just transmitting time independent of physiology. Yet several studies show that the SCN is involved in the etiology of hypertension. Here, we demonstrate that the SCN is incorporated in a neuronal feedback circuit arising from the nucleus tractus solitarius (NTS), modulating cardiovascular reactivity. ⋯ Examining this possibility we observed that elevation of BP, induced by α1-agonist infusion, was more than twice the magnitude in SCN-lesioned animals as compared to in controls, indicating indeed an active involvement of the SCN in short-term BP regulation. We propose that the SCN receives BP information directly from the NTS enabling it to react to hemodynamic perturbations, suggesting the SCN to be part of a homeostatic circuit adapting BP response. We discuss how these findings could explain why lifestyle conditions violating signals of the biological clock may, in the long-term, result in cardiovascular disease.
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We investigated the effect of taurine on inflammatory cytokine expression, on astrocyte activity and cerebral edema and functional outcomes, following traumatic brain injury (TBI) in rats. 72 rats were randomly divided into sham, TBI and Taurine groups. Rats subjected to moderate lateral fluid percussion injury were injected intravenously with taurine (200mg/kg) or saline immediately after injury or daily for 7days. Functional outcome was evaluated using Modified Neurological Severity Score (mNSS). ⋯ Compared with the TBI group, taurine significantly suppressed growth-related oncogene (GRO/KC) and interleukin (IL)-1β levels while elevating the levels of regulated on activation, normal T cell expressed and secreted (RANTES) at 1day. And taurine markedly decreased the level of 17 cytokine: eotaxin, Granulocyte colony-stimulating factor (G-CSF), Granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-γ), IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, IL-17, leptin, monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), and only increased the level of MIP-1α in a week. The results suggest that taurine effectively mitigates the severity of brain damage in TBI by attenuating the increase of astrocyte activity and edema as well as pro-inflammatory cytokines.
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Missense mutation R192Q in the CACNA1A gene causes familial hemiplegic migraine type-1 (FHM1), a monogenic subtype of migraine with aura. Using knock-in (KI) gene targeting we introduced this mutation into the mouse gene and generated a transgenic mouse model to investigate basic mechanisms of migraine pathophysiology. While FHM1 R192Q KI trigeminal ganglia were previously shown to exhibit constitutive up-regulation of ATP-gated P2X3 receptors, little is known about the firing properties of trigeminal sensory neurons, which convey nociceptive inputs to higher brain centers. ⋯ Activation by α,β-methyl-ATP was associated with a transient cluster of action potentials, while capsaicin elicited more persistent firing. Using α,β-methyl-ATP or capsaicin, two functional classes of WT or KI neurons were distinguished according to the first spike latency, which suggests that a subgroup of neurons may be indirectly activated, probably via crosstalk between neurons and satellite glial cells. Thus, our results are consistent with reported facilitated trigeminal pain behavior of FHM1 R192Q KI mice.
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CHF5074 is a nonsteroidal anti-inflammatory derivative that has been shown to inhibit β-amyloid plaque deposition and to reverse memory deficit in vivo in transgenic mouse models of Alzheimer's disease (AD). In the present in vivo study we used pre-plaque Tg2576 mice showing cognitive impairments to investigate the effects of a sub-acute treatment with CHF5074 on prefrontal cortex dialysate glutamate levels. Furthermore, the effects of CHF5074 have been compared with those induced, under the same experimental conditions, by LY450139, a potent γ-secretase inhibitor, that has been shown to inhibit brain β-amyloid production. ⋯ After these treatments, the injection of CHF5074 reduced, while LY450139 increased, prefrontal cortex dialysate glutamate levels in Tg2576 mice, but not in wild-type animals. These results suggest that at the dose tested CHF5074 and LY450139 differently affect cortical glutamate transmission in pre-plaque Tg2576 mice. This different neurochemical profile could be involved in the different ability of the two drugs in improving early cognitive performance in this animal model of AD.