Watermaze learning enhances excitability of CA1 pyramidal neurons.
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.
Oh
M Matthew
MM
Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA. mattoh@northwestern.edu
Kuo
Amy G
AG
Wu
Wendy W
WW
Sametsky
Evgeny A
EA
Disterhoft
John F
JF
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D066298:In Vitro Techniques; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344