Neuroscience
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Carbon monoxide (CO), like other gaseous neuromodulators, has a dual nature as both a toxic gas and a physiologically relevant signaling molecule. In the nervous system, high concentrations of CO can lead to neuronal injury while lower concentrations are found to be neuroprotective. The number of cellular targets affected by physiological concentrations of CO is rapidly growing and includes ion channels in various cell types. ⋯ This effect was mediated by the inhibition of voltage-gated calcium channels by CO. The general findings of CO acting as a hyperpolarizing signal and an inhibitor of neuronal excitability extended to B19 neurons. Taken together, these findings suggest that CO is a potent modulator of ion channels with broad implications for the modulation of neural activity in a wide range of neuron-types.
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The amygdala is a heterogeneous group of nuclei that plays a role in emotional and social learning. As such, there has been increased interest in its development in adolescent animals, a period in which emotional/social learning increases dramatically. While many mechanisms of amygdala development have been studied, the role of cell proliferation during adolescence has received less attention. ⋯ We conclude that typical neurogenesis is not a feature of the adolescent amygdala. These findings point to several possibilities, including the possibility that DCX/BrdU cells are late-developing neural precursors, or a unique subtype of NG2 cell that is relatively resistant to stress. In contrast, many proliferating OPCs are significantly impacted by a short-lived stressor, suggesting consequences for myelination in the developing amygdala.
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Low body weight gain and food intake are related to exhaustive training and overtraining; however, the molecular mechanisms responsible for these alterations remain unknown. The main aim of this study was to evaluate the effects of running overtraining (OT) protocols performed downhill, uphill and without inclination on the inflammatory pathway in the mouse hypothalamus. The rodents were randomized into the control (C), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up) and overtrained by running without inclination (OTR) groups. ⋯ The serum leptin levels were lower for the OTR group compared with the CT group at week eight. In conclusion, the OTR/down protocol induced transitory hypothalamic inflammation with concomitant reductions in the body weight and food intake. After the 2-week total recovery period, the OTR/down group had reversed the hypothalamic inflammation, with the concomitant normalization of the body weight and food intake.
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C-terminal binding proteins (CtBPs) are transcriptional co-repressors which cooperate with a variety of transcription factors to repress gene expression. Caenorhabditis elegans CTBP-1 expression has been observed in the nervous system and hypodermis. In C. elegans, CTBP-1 regulates several processes including Acute Functional Tolerance to ethanol and functions in the nervous system to modulate both lifespan and expression of a lipase gene called lips-7. ⋯ CTBP-1 is prominently expressed in the nervous system with weak expression detected in the hypodermis. Surprisingly, solely expressing CTBP-1a in the nervous system or hypodermis did not restore correct SMDD axonal structure in a ctbp-1 mutant. Our results demonstrate a role for CTBP-1 in exploration behavior and the regulation of SMDD axonal morphology in C. elegans.
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Microglia are the prime cellular sources of reactive oxygen species (ROS) in the central nervous system (CNS). Chronic activation of microglia has been linked to aging-associated neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) since they produce excessive amounts of ROS for a prolonged duration leading to oxidative stress. The present study was aimed at investigating the expression and role of Sirtuin 3 (Sirt3), a protein deacetylase which is implicated in regulating cellular ROS levels. ⋯ Conversely, Sirt3 overexpression led to increase in the expression of antioxidants Cat and mnSod. Further, increase in the expression and nuclear translocation of Foxo3a was observed following Sirt3 overexpression, suggesting that Sirt3 regulates ROS by inducing the expression of antioxidants via activation of Foxo3a. The above results point to an antioxidant defense mechanism presented by Sirt3 through the activation of Foxo3a, in microglia.