title: Long-term decrease in immediate early gene expression after electroconvulsive seizures.
abstract: Electroconvulsive therapy (ECT) is a well-established psychiatric treatment for severe depression. Despite its clinical utility, post-ECT memory deficits are a common side effect. Neuronal plasticity and memory consolidation are intimately related to the expression of immediate early genes (IEG), such as Egr1, Fos and Arc. Changes in IEG activation have been postulated to underlie long-term neuronal adaptations following electroconvulsive seizures (ECS), an animal model of ECT. To test this hypothesis, we used real-time PCR to examine the effect of acute and chronic ECS (8 sessions, one every other day) on the long-term (>24 h) expression of IEG Egr1, Fos and Arc in the hippocampus, a brain region implicated both in the pathophysiology of depression as well as in memory function. We observed a transient increase in Egr1 and Fos expression immediately after ECS, followed by a long-term decrease of IEG levels after both acute and chronic ECS. A separate group of animals, submitted to the same chronic ECS protocol and then subjected to open field or passive avoidance tasks, confirmed robust memory deficits 2 weeks after the last chronic ECS. The possible role of IEG downregulation on long-term learning deficits observed following ECS are discussed.
authors.affiliation: Laboratório de Neurociências-LIM-27, Faculdade de Medicina da Universidade de São Paulo-USP, Hospital das Clínicas, Instituto de Psiquiatria, São Paulo, SP, Brazil.
authors.forename: Julien Braga
authors.initials: JB
authors.lastname: Calais
authors.forename: Samira S
authors.initials: SS
authors.lastname: Valvassori
authors.forename: Wilson R
authors.initials: WR
authors.lastname: Resende
authors.forename: Gustavo
authors.initials: G
authors.lastname: Feier
authors.forename: Maria Carolina Pedro
authors.initials: MC
authors.lastname: Athié
authors.forename: Sidarta
authors.initials: S
authors.lastname: Ribeiro
authors.forename: Wagner Farid
authors.initials: WF
authors.lastname: Gattaz
authors.forename: João
authors.initials: J
authors.lastname: Quevedo
authors.forename: Elida Benquique
authors.initials: EB
authors.lastname: Ojopi
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology; D004565:Electroconvulsive Therapy; D004597:Electroshock; D005106:Exploratory Behavior / Q000502:physiology; D015870:Gene Expression; D017781:Genes, Immediate-Early / Q000235:genetics*; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000235:genetics* / Q000378:metabolism