Epileptic tolerance: prior seizures protect against seizure-induced neuronal injury.
Heat shock proteins (HSPs) are induced by a variety of insults to the nervous system, including seizures, and may be neuroprotective. If this is so, prior induction of HSPs should decrease neuronal damage upon re-exposure to an injurious stimulus. To test this hypothesis in relation to seizures, bicuculline was given to rats in two sessions, separated by 1, 3, 5 or 7 days; seizure activity was recorded, and HSP-like immunoreactivity and neuronal injury (acid-fuchsin staining) were quantified in the CA3c sector of the hippocampus. Prior seizures conferred a time-dependent protective effect against hippocampal injury induced by subsequent seizures, which may represent 'epileptic tolerance', analogous to the previously described phenomenon of 'ischemic tolerance'.
Sasahira
M
M
Department of Neurology, University of Pittsburgh, PA 94110, USA.
Lowry
T
T
Simon
R P
RP
Greenberg
D A
DA
D000818:Animals; D001640:Bicuculline / Q000494:pharmacology*; D004827:Epilepsy / Q000503:physiopathology*; D006360:Heat-Shock Proteins; D006624:Hippocampus / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000503:physiopathology*
D006360:Heat-Shock Proteins; D001640:Bicuculline