Gender differences in initiation and expression of behavioural sensitization to MDMA (ecstasy) effects in mice
Authors | |
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Year of publication | 2005 |
Type | Article in Proceedings |
Conference | Neuro-glia Interaction in Aging and Disease |
MU Faculty or unit | |
Citation | |
Field | Pharmacology and pharmaceutical chemistry |
Keywords | MDMA; behavioral sensitization; gender differences |
Description | Repeated exposure to drugs of abuse is known to cause persistent behavioural sensitization to their effects, what evoke reinstatement of previously extinguished drug-seeking behaviour. Various studies indicate that the neural systems that undergo sensitization are sexually dimorhpic, and thus, individual differences contingent on gender or age might exist. In rodents this phenomenon is apparent namely in stimulation of locomotion. As a first step, the current study was designed for examination if there are gender differences in both initiation and expression of MDMA-induced behavioural sensitization in mice. This drug was reported initiate behavioural sensitization increasing motor activity in male rats (Kalivas, 1998), and male mice (Itzhak, 2004). We evaluated behavioural changes particularly in locomotor activities in the mouse open field test using Panlab Actitrack apparatus. The results showed in males: a) significant stimulatory influence of MDMA after the acute administration, b) initiation of significant sensitization after MDMA repeated treatment, c) significant expression of sensitization after MDMA challenge dose given after 6 day washout from the repeated MDMA treatment. In females: a) significant stimulatory influence of MDMA after the acute administration, b) no significant behavioural changes suggesting initiation of sensitization after MDMA repeated treatment, c) significant expression of sensitization after MDMA challenge dose given after 6 day washout from the repeated MDMA treatment. Nevertheless, that the present results show the differential development of behavioural sensitization in male and female mice (it was not apparent in females during repeated treatment, but expressed after the challenge dose in weaning animals) they are important from the point of view on MDMA-taking behaviour as mainly the expression of behavioural sensitization is considered to reinstate drug-seeking behaviour and that way contribute to the relapse of addictive behaviour. |
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