Abstract
A previous study investigating the effects of dopamine receptor antagonists administered before the first of two 24-h apart forced swim test (FST) sessions, provided evidence suggesting that evaluation of response efficacy – dependent on dopamine D2-like receptors – might play a role in setting the balance between active behaviours and immobility in this test. Regardless of the underlying mechanisms, the observation that the effects of drugs in the first session have consequences in the second session might be relevant for a better understanding of the FST in behavioural/functional terms. Thus, the first objective of this study was to investigate the consequences in the second session of the administration of the prototypic antidepressant drug imipramine before the first of two sessions. A second objective was to investigate the effect of dopamine D1-like and D2-like receptor blockade on the effects of imipramine. Imipramine (20 mg/kg) was administered 24-h, 6-h and 30-min before the first of two FST sessions performed 24-h apart. SCH 23390 (0.01, 0.04 mg/kg) or raclopride (0.0125, 0.25 mg/kg) were administered 30-min before the first session. Imipramine increased active behaviours both in the first and in the second session. Raclopride attenuated and SCH 23390 potentiated imipramine effects only in the first session and to a limited extent. These results show that imipramine administration before the first of two FST sessions induces an increase in active behaviours in the second session, and suggest that this effect is the consequence of the behavioural effects of imipramine in the first session.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.