The stressed out brain: Short and long term plasticity changes in the paraventricular nucleus of the hypothalamus

Abstract:  The paraventricular nucleus (PVN) of the hypothalamus is one of the final neural control points in the hypothalamus-pituitary-adrenal axis, which facilitates the mammalian response to stress.   To initiate the endocrine response to stress, neurons in the PVN release Corticotropin Releasing Hormone (CRH).  However, these neurons (PVN-CRH neurons) are plastic entities that can change their neural responses after repeated exposure to stressors.  Here, we investigated how PVN-CRH neurons change in response to stressors on the short-time scales and on the long time-scales by using in vivo optogenetics (miniscope recordings), and computational modelling in collaboration with the Bains' Lab at the Hotchkiss Brain Institute.   We find that on the short-time scales, PVN-CRH neurons collectively display the dynamics of a two-state, discrete attractor network, where PVN-CRH neurons collectively maintain an altered dynamical state after animals are exposed to stressors.  On the long time scales, we find that these neurons alter their single neuron dynamics to systematically shift their frequency-current relationships in response to synaptic plasticity.  At the heart of the mammalian response to stress is a plastic neural circuit that may maintain the neural basis for stress in the absence of stressors on the short-time scale, and maintain a homeostatic baseline response to stress on long-time scales. 

Brief Bio: Dr. Wilten Nicola is an assistant professor and Tier II Canada Research Chair in Computational Neuroscience in the Department of Cell Biology and Anatomy, at the Cumming School of Medicine in the University of Calgary.  His research focus in computational neuroscience is to investigate how the dynamics of single neurons or neuron models interact with and alter their connectivity via synaptic plasticity to creae emergent behaviours at the network and organism level.  His PhD was awarded in 2015 in Applied Mathematics at the University of Waterloo, after which he spent 3 years as postdoctoral researcher at Imperial College London.  He has published numerous well-regarded papers in journals such as Nature Neuroscience, Nature Communications, PLoS Computational Biology, Journal of Computational Neuroscience etc.

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Topic: KCN Event: Wilten Nicola

Time: Mar 25, 2021 10:00 Eastern Time (US and Canada)

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