Neural correlates of spatial short-term memory in the rodent frontal orienting field

Abstract

Event Abstract Back to Event Neural correlates of spatial short-term memory in the rodent frontal orienting field Jeffrey C. Erlich1*, Max Bialek1 and Carlos D. Brody1 1 HHMI and Princeton University, United States We have trained rats on a memory-guided delayed orienting task, inspired by delayed saccade tasks performed by human and non-human primates. The delayed orienting task requires rats to ’fixate’ by holding their nose in a central nose port while a light is on in the port. During the fixation, a brief sound (the "target stimulus") indicates to the rat whether it should orient to the right or to the left after the end of fixation in order to obtain a reward. The end of fixation is indicated by the offset of the center light. We randomly interleave two types of trials: memory and non-memory. In memory trials, the target stimulus is presented shortly after the beginning of fixation and 700 ms before its end. In these trials, the rat must inhibit the impulse to respond immediately and must also remember the reward location (either as a retrospective memory of the stimulus or a prospective motor plan/prediction of reward location). These two elements, inhibition and planning, make the delayed-orienting task suitable for understanding the neural basis of cognitive control. In non-memory trials, the target stimulus is presented at the end of the fixation period, and no memory is required for correct performance. The two types of trials allow us to distinguish activity associated with spatial memory from activity associated with fixation only. The electrophysiological properties of neurons in the rodent orientation system remain largely unexplored. One cortical area of potential interest is the Frontal Orienting Field (FOF, +2 AP, ±1.3 ML [mm from Bregma]). Previous anatomical data has suggested that the FOF is homologous to primate frontal eye fields: in particular, the FOF connects strongly to both prefrontal cortex and the superior colliculus. Nevertheless, almost no electrophysiological recordings from the FOF exist. To our knowledge, no previous studies have recorded from FOF using repeated, identically prepared trials requiring an orientation movement, whether memory or non-memory-based. We have now recorded from over 500 single-units from the FOF while rats performed the delayed orienting task. We found that a significant portion of neurons in this region (approx 30%) show spatial working memory: after the offset of the stimulus, and before the onset of the movement, firing rates are selective for the rat’s upcoming choice. We have preliminary lesion and pharmacological evidence indicating that unilateral disruption of activity in the FOF creates a contralateral impairment. For example, rats with left FOF lesions are impaired at making rightward responses. Thus, we have both correlational physiological evidence and causal evidence that the FOF is an important element of the rat’s neural circuit for spatial orientation and spatial short-term memory. Conference: Computational and Systems Neuroscience 2010, Salt Lake City, UT, United States, 25 Feb - 2 Mar, 2010. Presentation Type: Poster Presentation Topic: Poster session I Citation: Erlich JC, Bialek M and Brody CD (2010). Neural correlates of spatial short-term memory in the rodent frontal orienting field. Front. Neurosci. Conference Abstract: Computational and Systems Neuroscience 2010. doi: 10.3389/conf.fnins.2010.03.00019 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 17 Feb 2010; Published Online: 17 Feb 2010. * Correspondence: Jeffrey C Erlich, HHMI and Princeton University, Princeton, United States, jerlich@princeton.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jeffrey C Erlich Max Bialek Carlos D Brody Google Jeffrey C Erlich Max Bialek Carlos D Brody Google Scholar Jeffrey C Erlich Max Bialek Carlos D Brody PubMed Jeffrey C Erlich Max Bialek Carlos D Brody Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.