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Combined Lesions of Perirhinal and Entorhinal Cortex Impair Rats’ Performance in Two Versions of the Spatially Guided Radial-Arm Maze,☆☆

https://doi.org/10.1006/nlme.1997.3778Get rights and content

Abstract

The present study examined the effects of combined lesions of the entorhinal and perirhinal cortex (PRER) on performance of two versions of the spatially guided eight-arm radial maze. In the first version, all arms were baited and in each session the rats were allowed to explore the maze freely until they retrieved all of the reinforcers. PRER subjects were profoundly impaired in performance of this task, making fewer correct choices and more total errors than control subjects. In the second task, a delayed nonmatching to sample version of the radial-arm maze, each daily session was separated into two phases. In the first, predelay phase, four arms were open and the remaining four arms were blocked with clear Plexiglas barriers; subjects were permitted to visit each of the four arms and retrieve the reinforcers. In the second, postdelay phase, the subject was placed on the maze with free access to all eight of the arms, but only those arms that were blocked in the predelay phase contained reinforcers. Delays of either 10 min or 30 s separated the pre- and postdelay phases. PRER subjects were significantly impaired in their performance of this task at both delays, making fewer correct choices and more errors than controls; the magnitude of this deficit was not dependent on length of delay. These data suggest that, along with the hippocampal formation, the entorhinal and perirhinal cortices actively participate in the acquisition and performance of appetitively motivated spatial memory tasks.

References (29)

  • T.W. Berger et al.

    Long-term potentiation of entorhinal afferents to the hippocampus: Enhanced propagation of activity through the trisynaptic pathway

    Long-term potentiation. A debate of current issues

    (1990)
  • J.P. Bouffard et al.

    Acquisition of a complex place task in rats with selective ibotenate lesions of hippocampal formation: Combined lesions of subiculum and entorhinal cortex versus hippocampus

    Behavioral Neuroscience

    (1988)
  • Y.H. Cho et al.

    Extended temporal gradient for the retrograde and anterograde amnesia produced by ibotenate entorhinal cortex lesions in mice

    Journal of Neuroscience

    (1993)
  • H. Eichenbaum et al.

    Two functional components of the hippocampal memory system

    Behavioral and Brain Sciences

    (1994)
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    This research was supported by NIMH Grant R03-MH53880-01 and NSF Grant IBN9514526 to T.O. and NSF Grant IBN9514557 and a gift in memory of Colonel Norman C. Kalmar to T.J.W.

    Correspondence and reprint requests should be addressed to Tim Otto. E-mail: [email protected]. Fax: (908)445-2263.

    ☆☆

    M. BaudryJ. L. Davis, Eds.

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