Extensive cytotoxic lesions involving both the rhinal cortices and area TE impair recognition but spare spatial alternation in the rat

Brain Res Bull. 1997;43(3):279-87. doi: 10.1016/s0361-9230(97)00007-5.


Rats with cytotoxic lesions of the perirhinal, postrhinal, and TE cortices (Rh+TE, n = 7) were compared with surgical control animals (n = 7) on a series of spontaneous object recognition tests. The Rh+TE group was associated with a failure to select the novel object. This recognition deficit contrasted with the apparently normal ability of the same animals to learn and perform a spatial working memory test (T-maze alternation). The animals were also tested on the acquisition of an automated visual discrimination task in which the stimuli were presented on a visual display unit (VDU) equipped with a touch screen. The animals with Rh+TE lesions showed only a borderline deficit on this task. These findings are consistent with other evidence implicating the rhinal region in recognition memory. More importantly, they also provide a dissociation between spatial working memory and object recognition and, hence, show that extensive rhinal lesions are not sufficient to disconnect the hippocampus functionally.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cerebral Cortex / physiology*
  • Cognition / physiology*
  • Discrimination, Psychological / physiology*
  • Hippocampus / physiology*
  • Male
  • Maze Learning / physiology*
  • Rats