The role of the entorhinal cortex in two forms of spatial learning and memory

D. M. Bannerman, Kay Yan Benjamin Yee, M. Lemaire, L. Wilbrecht, L. Jarrard, S. D. Iversen, J. N.P. Rawlins, M. A. Good

Research output: Journal article publicationJournal articleAcademic researchpeer-review

54 Citations (Scopus)

Abstract

It is generally acknowledged that the rodent hippocampus plays an important role in spatial learning and memory. The importance of the entorhinal cortex (ERC), an area that is closely interconnected anatomically with the hippocampus, in these forms of learning is less clear cut. Recent studies using selective, fibre-sparing cytotoxic lesions have generated conflicting results, with some studies showing that spatial learning can proceed normally without the ERC, suggesting that this area is not required for normal hippocampal function. The present study compared cytotoxic and aspiration ERC lesions with both fimbria fornix (FFX) lesions and sham-operated controls on two spatial learning tasks which have repeatedly been shown to depend on the hippocampus. Both groups of ERC lesions were impaired during non-matching-to-place testing (rewarded alternation) on the elevated T-maze. However, neither of these lesions subsequently had any effect on the acquisition of a standard spatial reference memory task in the water maze. FFX lesions produced a robust and reliable impairment on both of these tasks. A second experiment confirmed that cytotoxic ERC lesions spared water maze learning but disrupted rewarded alternation on the T-maze, when the order of behavioural testing was reversed. These results confirm previous reports that ERC-lesioned animals are capable of spatial navigation in the water maze, suggesting that the ERC is not a prerequisite for normal hippocampal function in this task. The present demonstration that ERC lesions disrupt non-matching-to-place performance may, however, be consistent with the possibility that ERC lesions affect attentional mechanisms, for example, by increasing the sensitivity to recent reward history.
Original languageEnglish
Pages (from-to)281-303
Number of pages23
JournalExperimental Brain Research
Volume141
Issue number3
DOIs
Publication statusPublished - 1 Jan 2001
Externally publishedYes

Keywords

  • Entorhinal cortex
  • Fimbria fornix
  • Hippocampus
  • Rat
  • Spatial learning

ASJC Scopus subject areas

  • Neuroscience(all)

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