Date: Thursday, February 11, 2021
Time: 11am - 12pm
Event Address: Virtual via Zoom
Meeting ID: 997 1998 4464
Passcode: 179767

Title: “How Does Stress Affect Hippocampal Function?”

David Diamond received his Ph.D. in Biology in 1985, with a specialization in Behavioral Neuroscience, from the Center for the Neurobiology of Learning and Memory at the University of California, Irvine. Dr. Diamond recently retired as a Career Scientist from the Department of Veterans Affairs after 30 years of service.

He is currently a Professor in the Cognitive, Neural and Social Division of the Department of Psychology at the University of South Florida, where he has directed his animal and clinical research program on post-traumatic stress disorder and traumatic brain injury. Dr. Diamond has been funded by the VA, NIH, DoD, NSF and pharmaceutical companies in his neuroscience research, with over 140 publications, reviews and book chapters on the brain, stress and memory.

Abstract: Research spanning decades supports the hypothesis that hippocampal functioning is impaired by strong stressful experiences. The consensus in the field is that stress blocks the induction of hippocampal long-term potentiation (LTP) in rodents, and traumatic stress impairs the hippocampal contribution to memory in rodents and people. In my talk, I will present an alternative approach to how the hippocampus is affected by stress. I will review research which is inconsistent with the hypothesis that stress impairs hippocampal functioning. I will then provide an alternative hypothesis that incorporates the stress-LTP and trauma memory findings into a “temporal dynamics” model. This model provides a framework for understanding the neurobiological basis of flashbulb and traumatic memories. The essential feature of the model is that endogenous mechanisms of plasticity in the hippocampus and amygdala are rapidly activated for a brief period of time by a strong emotional experience. Following this brief activational period, the hippocampus undergoes a prolonged state in which the induction of plasticity is suppressed, thereby interfering with normative hippocampal functioning. Thus, with the onset of strong emotionality, the hippocampus rapidly shifts from a “configural/cognitive map” mode to a “flashbulb memory” mode, which underlies the long-lasting, but fragmented, nature of traumatic memories.