IS THERE A NEGATIVE CORRELATION BETWEEN A PHENELZINE SUB-ACUTELY INDUCED ANTIDEPRESSANT-LIKE BEHAVIOUR AND HIPPOCAMPAL 5-HT?

Objective The aim of the current study was to evaluate the behavioural activity (immobility time in the forced swim test; FST) of the antidepressant and anti-panic drug phenelzine in relation to any neurochemical corollaries (hippocampal noradrenaline and 5-HT levels) in rats. Methods The monoamines were determined using high performance liquid chromatography with electrochemical detection). Results Acute and 7-day sub-acute phenelzine treatments evoked a significant reduction in immobility time in the forced swim test with an ED 50 ~ 10.0 mg/kg. The decreased immobility time after both acute and sub-acute treatment was associated with significant elevation of hippocampal noradrenaline and 5-HT levels compared to control. Notably, there was a significant negative correlation between the sub-acute phenelzine dose-related decrement in augmented hippocampal 5-HT levels in the hippocampus with respect to FST performance. Conclusion This may suggest either that phenelzine antidepressant-like activity does not correlate closely with elevated 5-HT levels in the hippocampus and may signify that other mechanisms are more critically operative or that the FST is perhaps not the best predictor of antidepressant potential