Ca2+ release from Ca2+ stores, particularly from ryanodine-sensitive Ca2+ stores, is required for the induction of LTD in cultured cerebellar Purkinje cells. Kohda, Kazuhisa, Takafumi Inoue and Katsuhiko Mikoshiba. Department of Molecular Neurobiology, Institute of Medical Science, University of Tokyo. Tokyo, 108, Japan.
APStracts 2:0208N, 1995.
SUMMARY AND CONCLUSIONS
1. Primary-cultured cerebellar Purkinje cells (PCs) from mouse embryos were whole-cell voltage-clamped and L-glutamate (Glu) was applied iontophoretically to the dendrite. Long-term depression (LTD) of Glu-evoked currents was induced through the conjunction of repeated depolarizations and Glu applications. 2. Thapsigargin, a specific inhibitor of Ca2+-ATPase on the endoplasmic reticulum, and ryanodine and ruthenium red, inhibitors of the ryanodine receptor, blocked the induction of LTD. 3. Thapsigargin and ryanodine alone did not affect influx of Ca2+ through voltage-gated Ca2+ channels and inward currents evoked by Glu applications. 4. Our results suggest that Ca2+ release from internal stores, particularly from ryanodine-sensitive stores, is necessary for the induction of LTD in cultured PCs.

Received 20 April 1995; accepted in final form 7 July 1995.
APS Manuscript Number J268-5.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 July 1995.