Behavioral changes resulting from the administration of cycloheximide in the pilocarpine model of epilepsy.
Cycloheximide influences synaptic reorganization resulting from pilocarpine-induced status epilepticus (SE). To investigate the possible behavioral consequences of this effect, we subjected animals to pilocarpine-induced SE either in the absence (Pilo group) or presence of cycloheximide (Chx group). Animals were further divided regarding the occurrence of spontaneous recurrent seizures (SRS). Two months after SE induction animals were exposed to different behavioral tests. Age-matched naïve animals were used as controls. All epileptic groups showed a significantly diminished freezing time in contextual and tone fear conditioning, performed poorly in the Morris water maze and present less seconds in immobility position as compared to controls. Only Pilo animals explored more extensively the open arms of the elevated plus maze and showed increased in horizontal exploratory activity in the open field as compared to controls. With the exception of Pilo animals without recorded SRS, all other groups had extensive tissue shrinkage in central nucleus of the amygdala as compared to controls. Cycloheximide-treated animals differed from Pilo animals in the extent of hilar loss and supragranular mossy fiber sprouting as well as tissue shrinkage in the dorsal hippocampus. Despite the histological differences seen in the dorsal hippocampus between experimental groups, no differences were encountered in the cognitive tests used to evaluate dorsal hippocampal function. The encountered histological differences between Chx and Pilo animals, however, might underlie the different emotional responses between the two groups.
Dos Santos
Jair Guilherme
JG
Department of Psychobiology, Universidade Federal de São Paulo, R. Botucatu 862, 5 andar, 04023-062 São Paulo, Brazil.
Longo
Beatriz Monteiro
BM
Blanco
Mirian Marcela
MM
Menezes de Oliveira
Maria Gabriela
MG
Mello
Luíz Eugênio
LE
D000161:Acoustic Stimulation; D000818:Animals; D001007:Anxiety / Q000523:psychology; D001522:Behavior, Animal / Q000187:drug effects*; D002452:Cell Count; D003213:Conditioning, Psychological / Q000187:drug effects; D003513:Cycloheximide / Q000494:pharmacology*; D003863:Depression / Q000523:psychology; D004833:Epilepsy, Temporal Lobe / Q000139:chemically induced* / Q000523:psychology*; D005106:Exploratory Behavior / Q000187:drug effects; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D019599:Mossy Fibers, Hippocampal / Q000502:physiology; D018721:Muscarinic Agonists; D010862:Pilocarpine; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012008:Recurrence; D013550:Swimming / Q000523:psychology
D018721:Muscarinic Agonists; D011500:Protein Synthesis Inhibitors; D010862:Pilocarpine; D003513:Cycloheximide