Monday, November 21, 2011 12:00pm
Dr. Timothy Allen to give Behavioral Neuroscience Brown Bag Talk
Timothy A. Allen, Ph.D., from the Laboratory of Norbert J. Fortin, Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine will give a Behavioral Neuroscience Brown Bag talk titled: "Neural correlates of sequence memory". The talk will be held on November 21st in 108 Wolf Hall from 12-1 pm.
Episodic memory is defined as the capacity to remember specific events or experiences. Theoretically, the ability to encode and retrieve sequences of events is an essential feature of episodic memory. This view is consistent with traditional animal models of episodic memory that emphasize the coupling of the memory for a specific item (or event) with information about the spatial and/or temporal context (such as "what-where-when" memory), but builds upon them by operationally defining the "temporal context" as the memory for the order in which events occurred during an experience. Despite considerable effort, the fundamental neurobiological mechanisms underlying episodic memory remain poorly understood. Here I present a novel odor sequence task developed in rats. Similar to humans, rats perform well in the sequence task, demonstrating a robust ability to remember the order of events. During performance on the task, single-unit recordings were conducted in the hippocampus (HC) and the medial prefrontal cortex (mPFC). The neural responses in the HC and mPFC form a dynamically changing set of representations before, during and after an odor is presented suggesting a logical and plausible series of computations necessary to solve the sequence task: (1) the mPFC prospectively codes for the upcoming odor, (2) the HC identifies the current odor stimulus, (3) the mPFC codes for the current ordinal position, (4) the HC then indicates an odor-position match/mismatch based on previous experience, (5) the mPFC selects an appropriate action, and (6) the mPFC responds to incorrect responses providing a possible teacher signal. The results support the premise that sequence memory capacities emerge, in part, from a HC-PFC system.