Long-term cosequences of intrahippocampal kainate injection in the Proechimys guyannensis rodent.
The Proechimys guyannensis (PG), a spiny rodent specie living in the Amazonian region has been recently studied as an animal model of anti-convulsant mechanisms. The PG was found to be resistant to the administration of the muscarinic cholinergic agonist pilocarpine or the amygdala kindling development. This study examined the susceptibility of this animal species to the intrahippocampal kainic acid (KA) injection. Electrographic, behavioral and neuropathological changes induced by intrahippocampal KA injections were analyzed. PG showed to be extremely sensitive to the acute effects of the KA injection. Although the EEG findings in PG rodents were similar to those typically obtained in Wistar rats the pattern of electrographic activity in PG animals was longer than in Wistar rats. Neuropathological examinations of PG brains that survived KA-induced SE revealed severe cell loss in CA1/CA3 areas of the hippocampus, an extensive cell dispersion in the hilus of DG at the injected site with mossy fiber sprouting in the dentate gyrus supragranular layer. None of PG animals presented spontaneous seizures during the 120 days of observation. These findings confirm our previous observation on the resistance of this animal specie to experimental models of limbic epilepsy.
Arida
Ricardo Mario
RM
Disciplina de Neurologia Experimental, Universidade Federal de São Paulo (UNIFESP), Rua Botucatú 862, Vila Clementino, CEP 04023-9000, São Paulo, SP, Brazil. arida.nexp@epm.br
Scorza
Fulvio Alexandre
FA
Carvalho
Reinaldo de Amorim
Rde A
Cavalheiro
Esper Abrão
EA
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004569:Electroencephalography / Q000379:methods; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D007608:Kainic Acid / Q000633:toxicity*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012377:Rodentia; D013995:Time
D018690:Excitatory Amino Acid Agonists; D007608:Kainic Acid