Behavioral, morphologic, and electroencephalographic evaluation of seizures induced by intrahippocampal microinjection of pilocarpine.
OBJECTIVE
We studied, by means of video-EEG and neo-Timm histochemistry, the behavioral, electrophysiologic, and structural characteristics of seizures induced by intrahippocampal microinjection of pilocarpine (HIP-PILO), a selective model of temporal lobe epilepsy (TLE).


METHODS
We investigated the behavioral and electrophysiologic (hippocampus and amygdala EEG) evaluation of status epilepticus (SE) induced by HIP-PILO and the consequent spontaneous recurrent seizures (SRSs). We evaluated hippocampal structural rearrangements after SE by means of neo-Timm staining.


RESULTS
HIP-PILO induced SE in 17 (71%) of 24 animals. Although three animals displayed spontaneous remission of SE (not used in analysis) before the established SE duration (90 min), none of those undergoing SE died. Of SE animals, 10 (71%) of 14 had SRSs. All animals with SE had clear-cut mossy fiber sprouting (MFS) in the inner molecular layer of the dentate gyrus and epileptiform activity in hippocampus and amygdala.


CONCLUSIONS
HIP-PILO rats displayed SE, SRS, MFS, and limbic epileptiform activity, without animal loss after SE. Thus, our data support this as a selective and efficient model of TLE.
Neurophysiology and Experimental Neuroethology Laboratory, Physiology Department, Ribeirão Preto School of Medicine, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil.
Marcio de A
Mde A
Furtado
Glaucia K
GK
Braga
José A C
JA
Oliveira
Flavio
F
Del Vecchio
Norberto
N
Garcia-Cairasco
D000818:Animals; D001522:Behavior, Animal; D003292:Convulsants / Q000008:administration & dosage; D004195:Disease Models, Animal; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000139:chemically induced / Q000503:physiopathology / Q000523:psychology; D006624:Hippocampus; D008845:Microinjections; D010862:Pilocarpine / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D013226:Status Epilepticus / Q000139:chemically induced* / Q000503:physiopathology* / Q000523:psychology
D003292:Convulsants; D010862:Pilocarpine