Stimulation at 1-5 Hz does not produce long-term depression or
depotentiation in the hippocampus of the adult rat in vivo .
Errington, M.L., T.V.P. Bliss, G.Richter-Levin, K. Yenk, V. Doyere and S.
Laroche.
Division of Neurophysiology, National Institute for Medical Research, Mill
Hill, London NW7 1AA, U.K., *Laboratoire de Neurobiologie de l'Apprentissage
et de la M[acute]emoire, CNRS URA 1491, Universit[acute]e de Paris Sud, 91405
Orsay, France.
APStracts 2:0189N, 1995.
SUMMARY AND CONCLUSIONS
1. We have examined the efficacy of low-frequency trains (1-5Hz) in producing
LTD or depotentiation in the hippocampus of the awake adult rat, and in
anaesthetized rats aged from 10 days to 3 months. 2. In the dentate gyrus we
found no evidence that low-frequency trains produce either depotentiation or
LTD in the awake, adult animal, or in the anaesthetized animal at any age
tested (10 days - adult). 3. In area CA1 of both awake and anaesthetized adult
rats, we also found no evidence that low-frequency trains induced either LTD
or depotentiation. Only in area CA1 of very young rats (10-11 days) was clear
evidence for LTD and depotentiation obtained; at this age experiments were
only possible in anaesthetized animals. By 16 days, the ability to display
both LTD and depotentiation was lost. 4. These experiments suggest that
repetitive low-frequency stimulation evokes a developmentally-regulated form
of activity-dependent depression which in the hippocampus is limited to
specific pathways in the young animal. Our results leave open the question of
whether alternative patterns of activity can induce LTD and/or depotentiation
in the adult awake rat.
Received 27 April 1995; accepted in final form 29 June 1995.
APS Manuscript Number J283-5.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 18 July 1995.