Watermaze learning enhances excitability of CA1 pyramidal neurons

J Neurophysiol. 2003 Oct;90(4):2171-9. doi: 10.1152/jn.01177.2002. Epub 2003 Jun 18.


The dorsal hippocampus is crucial for learning the hidden-platform location in the hippocampus-dependent, spatial watermaze task. We have previously demonstrated that the postburst afterhyperpolarization (AHP) of hippocampal pyramidal neurons is reduced after acquisition of the hippocampus-dependent, temporal trace eyeblink conditioning task. We report here that the AHP and one or more of its associated currents (IAHP and/or sIAHP) are reduced in dorsal hippocampal CA1 pyramidal neurons from rats that learned the watermaze task as compared with neurons from control rats. This reduction was a learning-induced phenomenon as the AHP of CA1 neurons from rats that failed to learn the hidden-platform location was similar to that of neurons from control rats. We propose that reduction of the AHP in pyramidal neurons in regions crucial for learning is a cellular mechanism of learning that is conserved across species and tasks.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials / physiology*
  • Animals
  • In Vitro Techniques
  • Male
  • Maze Learning / physiology*
  • Pyramidal Cells / physiology*
  • Rats
  • Rats, Inbred BN
  • Rats, Inbred F344