SPIRAL INTERCELLULAR CALCIUM WAVES IN HIPPOCAMPAL SLICE CULTURES.
Marni E. Harris-White, Stephen A. Zanotti, Sally A. Frautschy, and Andrew C.
Charles.
Department of Medicine, UCLA/VA Medical Center, Sepulveda, Department of
Neurology, UCLA School of Medicine.
APStracts 4:290N, 1997.
ABSTRACT
Complex patterns of intercellular calcium signaling occur in the CA1 and CA2
regions of hippocampal slice organotypic cultures from neonatal mice.
Spontaneous, localized intercellular Ca2+ waves involving 5-15 cells propagate
concentrically from multiple foci in the stratum oriens and stratum radiatum.
In these same regions, extensive intercellular Ca2+ waves involving hundreds
of cells propagate as curvilinear and spiral wavefronts across broad areas of
CA1 and CA2. Intercellular Ca2+ waves propagate at rates of 5-10 æm/sec, are
abolished by thapsigargin, and do not require extracellular Ca2+. Staining for
astrocytes and neurons indicate that these intercellular waves occur primarily
in astrocytes. The frequency and amplitude of intercellular Ca2+ waves
increase in response to bath application of N-methyl-D-aspartate, and decrease
in response to removal of extracellular Ca2+ or application of tetrodotoxin
. This novel pattern of intercellular calcium signaling is characteristic of
the behavior of an excitable medium. Networks of glial cells in the
hippocampus may behave as an excitable medium whose spatial and temporal
signaling properties are modulated by neuronal activity.
Received 15 July 1997; accepted in final form 14 October 1997.
APS Manuscript Number J590-7.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 29 October 1997