ABSTRACT:
Evidence from both animal and human studies suggests a role for serotonin in the therapeutic effect of antidepressant drugs. The antidepressant effect of gabapentin was investigated in mice using the forced swim test, tail suspension test, and open-field test. Gabapentin produced an antidepressant-like effect, since the administration of gabapentin at doses of 1, 3 and 6?mg/kg,i.p.1hr prior to the test session, significantly reduced the immobility time in both the forced swim test and tail suspension test, compared with the control group, without accompanying changes in ambulation in the open-field test. Moreover, Gabapentin dose dependently increases the plasma serotonin. Taken together, these results indicate that gabapentin possessed an antidepressant-like effect in mice, which may be mediated by the central monoaminergic neurotransmitter system. The present results indicates an involvement of serotonin transmission in the gabapentin antidepressant-like effect in the despair animal models of depression, and suggest that this effect depends mainly on stimulation of serotonergic receptors.