Mechanical Perturbation of Cultured Cortical Neurons Reveals a Stretch- Induced Delayed Depolarization. Tavalin, Steven J., Earl F. Ellis and Leslie S. Satin. Department of Pharmacology and Toxicology and Department of Physiology, Medical College of Virginia, Richmond, VA 23298-0524.
APStracts 2:0292N, 1995.
SUMMARY AND CONCLUSIONS
1. An in vitro cellular model of injury was used to elucidate mechanisms contributing to traumatic brain injury (TBI). Neonatal rat cortical neurons cultured on a flexible silastic membrane were rapidly and reversibly stretched by a 50 ms pulse of pressurized air. 2. Sublethal cell stretch depolarized neuronal resting membrane potential by approximately 10 mV but only if cells were incubated for 1 hr following injury. Stretch-induced delayed depolarization (or SIDD) returned to baseline values within 24 hours. 3. SIDD was dependent on the degree of cell stretch and required neuronal firing, calcium entry, and NMDA receptor activation for its induction but not its maintainance. 4. Similarities between SIDD and TBI suggest that SIDDÊmay play a role in brain injury. 

Received 7 August 1995; accepted in final form 28 September 1995.
APS Manuscript Number J515-5.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95