Acute stress effects on cognition and synaptic plasticity

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The goal of my research program is to understand the effects of experience on cognition and the physiology of the brain. To this end, I examine cognitive processes such as memory under normal conditions and following acute stress. Acute stress strongly influences cognition and I am interested in discovering the changes in brain physiology that mediate these influences. While previous research shows that acute stress dramatically alters the communication between neurons in the brain, the effects of acute stress on patterns of brain activity while cognitive tasks are being performed are unknown. My research uses an integrative approach with behavioural, pharmacological, and electrophysiological techniques in rats to address these questions. The specific experiments proposed address four objectives related to recognition memory, a process whereby a stimulus is judged to have been seen previously, and the brain circuits that mediate this form of cognition. I plan to examine how neurotransmitters receptors are regulated during object recognition memory using novel pharmacological tools in behaving animals. I will also characterize the surprising improvement in performance observed following acute stress using a system with touch sensitive screens to test visual learning and memory in rats. In parallel experiments, I will test the effects of acute stress on patterns of short-term and long-term synaptic plasticity using electrophysiology in anesthetized and freely moving rats. The role of glucocorticoid receptors, proteins that are activated by the stress hormone corticosterone, in the effects acute stress on synaptic plasticity in the brain areas involved in recognition memory will be assessed. My final objective is to conduct electrophysiological recordings while rats perform the recognition memory tests in an effort to understand the specific alterations in on-going brain activity that result from periods of acute stress. An integrated understanding of the fundamental behavioural and electrophysiological effects of acute stress on memory will allow the development of theories regarding the brain mechanisms mediating cognition in both normal and challenging circumstances.