Mechanical perturbation of cultured cortical neurons reveals a stretch-induced delayed depolarization.
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 stretched rapidly and reversibly 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 h after injury. Stretch-induced delayed depolarization (or SIDD) returned to baseline values within 24 h. 3. SIDD was dependent on the degree of cell stretch and required neuronal firing, calcium entry, and N-methyl-D-aspartate receptor activation for its induction but not its maintainance. 4. Similarities between SIDD and TBI suggest that SIDD may play a role in brain injury.
Tavalin
S J
SJ
Department of Pharmacology, Medical College of Virginia, Richmond 23298-0524, USA.
Ellis
E F
EF
Satin
L S
LS
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000293:injuries / Q000502:physiology*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004594:Electrophysiology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D008465:Mechanoreceptors / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D013779:Tetrodotoxin / Q000494:pharmacology
D018691:Excitatory Amino Acid Antagonists; D013779:Tetrodotoxin; D016291:Dizocilpine Maleate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione