APStracts 4:301N, 1997.

EFFECTS OF HYPOSMOLAR SOLUTIONS ON MEMBRANE CURRENTS OF HIPPOCAMPAL INTERNEURONS AND MOSSY CELLS IN VITRO Scott C. Baraban and Philip A. Schwartzkroin Departments of Neurological Surgery and Physiology/Biophysics, University of Washington, Seattle, WA..

APStracts 4:301N, 1997.

ABSTRACT
Whole-cell voltage-clamp recordings in rat hippocampal slices were used to investigate the effect of changes in extracellular osmolarity on voltage- activated potassium currents. Currents were evoked from oriens/alveus interneurons, hilar interneurons and mossy cells. Hyposmolar external solutions produced a significant potentiation of K+ current recorded from oriens/alveus and hilar interneurons, but not from mossy cells. Hyposmolar solutions also dramatically potentiated the spontaneous excitatory postsynaptic currents recorded from mossy cells. These results suggest that hippocampal excitability can be modulated by the complex actions exerted by changes in extracellular osmolarity.

Received 5 August 1997; accepted in final form 22 October 1997.
APS Manuscript Number J638-7.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 14 November 1997