Typical and atypical antidepressant drug effects on locomotor activity after intra-accumbens injections in the rat.

Changes in spontaneous or drug-induced locomotor activity in rats were studied after injection of antidepressants in the nucleus accumbens. Antidepressant drugs, either alone or in combination with ergometrine, were injected bilaterally via fixed guide cannulas into the nucleus accumbens and locomotor activity was recorded during a period of 5 h. The after-effect, a long-lasting change in ergometrine-induced locomotor activity after priming with an antidepressant drug was also studied. It was concluded that: (a) The nucleus accumbens is a target site for antidepressant drugs in the rat. (b) Antidepressant drugs with mainly dopaminergic, noradrenergic or serotonergic features each show different effects in the test battery. (c) Typical as well as atypical antidepressants show common features.