title: Enhancement of hippocampal long-term potentiation induced by cocaine self-administration is maintained during the extinction of this behavior.
abstract: Drug addiction may involve learning and memory processes requiring the participation of hippocampal formation. One of the best studied examples of hippocampal synaptic plasticity is the long-term potentiation (LTP) which usually occurs when hippocampal synapses are stimulated with high-frequency stimulation. The aim of this work has been to study the effect of extinction of cocaine self-administration behavior on synaptic plasticity in rat hippocampal slices. LTP was induced using a tetanization paradigm consisting of a single train of high-frequency (100 Hz) stimulation for one second. This tetanization protocol evoked a greater and more perdurable LTP in slices obtained after 10 days of extinction of cocaine self-administration (1 mg/kg/injection) than that elicited in slices from saline self-administering (0.9% NaCl) animals. In addition, this LTP facilitation in animals which have followed the cocaine self-administration extinction protocol was very similar to that obtained in slices from cocaine self-administering animals. These results suggest that chronic cocaine self-administration induces enduring neuroadaptive changes in hippocampal synaptic plasticity which last even after the extinction of this behavior and that they may be involved in cocaine dependence.
authors.affiliation: Departamento de Psicobiología, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), C/Juan del Rosal no 10, 28040 Madrid, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: del Olmo
authors.forename: Miguel
authors.initials: M
authors.lastname: Miguéns
authors.forename: Alejandro
authors.initials: A
authors.lastname: Higuera-Matas
authors.forename: Isabel
authors.initials: I
authors.lastname: Torres
authors.forename: Carmen
authors.initials: C
authors.lastname: García-Lecumberri
authors.forename: José María
authors.initials: JM
authors.lastname: Solís
authors.forename: Emilio
authors.initials: E
authors.lastname: Ambrosio
mesh_terms: D000818:Animals; D001369:Axons / Q000187:drug effects; D003042:Cocaine / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000523:psychology*; D003216:Conditioning, Operant / Q000187:drug effects; D004594:Electrophysiology; D005108:Extinction, Psychological / Q000187:drug effects*; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects*; D017774:Long-Term Potentiation / Q000187:drug effects*; D008297:Male; D009474:Neurons / Q000187:drug effects; D051381:Rats; D011917:Rats, Inbred Lew; D012055:Reinforcement Schedule; D012646:Self Administration; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
chemical_list: D003042:Cocaine