Impacto das diferenças individuais observadas na sensibilização locomotora sobre o reforço condicionado: uma comparação entre modafinil e metanfetamina

• Ano de defesa: 2015
• Autor(a) principal: Soeiro, Aline da Costa [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: dependência; condicionamentode preferência ao lugar; dopamina; via mesocorticolímbica; drogas de abuso
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=2688078; http://repositorio.unifesp.br/handle/11600/48326

Locomotor sensitization induced by psychostimulants can affect reward and conditioned drug effects and modify drug seeking and taking behaviors. The aim of the present study was to assess a potential relationship between individual differences in locomotor sensitization and conditioned rewarding effects of modafinil and methamphetamine. For the induction and expression of locomotor sensitization, Swiss albino male mice were allocated to receive 10 daily administrations of vehicle or drug (modafinil or methamphetamine). Following 5 and 7 days of withdrawal, animals underwent an acute administration of vehicle and drug, respectively. According to the locomotor response displayed on the last administration day (day 10), drug-treated groups were redistributed into 2 subgroups: sensitized (SENS) and non-sensitized (NSENS). After 5 days, conditioned place preference protocol was conducted, consisting of 8 or 12 daily conditioning sessions. Prior to each conditioning session, each animal received vehicle or drug administration on alternating days. Locomotor sensitization to modafinil caused a loss of conditioning score in the SENS subgroup. In this case, higher levels of sensitization appear to attenuate sensitivity to conditioned rewarding effects. In contrast, animals resilient to methamphetamine-induced locomotor sensitization (NSENS) showed resistance to conditioning at low, but not high doses of methamphetamine. In this case, animals with low levels of locomotor sensitization demonstrated lower sensitivity to methamphetamine-conditioned rewarding effects. There was no cross-sensitization with conditioned rewarding effects between modafinil and methamphetamine. Our data revealed that the impact of individual differences in locomotor sensitization on conditioned rewarding effects seems to be dependent on the specific drug and doses. In addition, it can be suggested that sensitization to modafinil modulates conditioned rewarding effects in a distinct way than methamphetamine.