The Department of Biomedicine

BBB seminar: Brian E. Derrick

Novelty and synaptic plasticity in the hippocampal formation

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Brian E. Derrick
Cajal Neuroscience Institute, Department of Biology, University of Texas at San Antonio, TX, USA

The formation of memory in the brain involves neural operations that enable the encoding and retrieval of information. However, it is not easy to have both plasticity and stability in neural networks. Difficulties arise when plasticity allows new information to interfere with previously encoded information, or when new information is corrupted by previously encoded information. I shall present several mechanisms by which the hippocampal formation, a structure implicated in memory, handles this dilemma, including enhanced synaptic plasticity associated with novelty detection, serotonergic regulation of this plasticity, cholinergic dampening of recurrent excitation in the hippocampal CA3 region, and granule cell neurogenesis that facilitates pattern separation of both novel and familiar dentate inputs. These findings support a number of specific predictions of information-theoretic models of dynamic hippocampal information processing.

Host: Clive Bramham, Department of Biomedicine

Brian Derrick received a PhD in Biopsychology from the University of California at Berkeley. Currently he is an Associate Professor of Neurobiology at the Department of Biology at the University of Texas, San Antonio, and also a Principal Investigator at the Cajal Neuroscience Research Center at UTSA. His primary interest is the functional and computational aspects of information storage and retrieval in the cortical-dentate-CA3 interface of the hippocampal formation. Research in Derrick's laboratory is primarily using the LTP (long-term potentiation) model of synaptic plasticity, and current, testable theoretical models of dynamic CA3 function (Hasselmo, Levy, Treves and Rolls). In addition, Dr. Derrick's laboratory is investigating the functional roles of adult granule cell neurogenesis, and the regulation of LTP and neurogenesis by novelty, theta rhythm and monoaminergic neuromodulators, particularly in relation to behavioral state.