EFFECTS OF TRAZODONE AND DESPIRAMINE ON MOTOR RECOVERY IN BRAIN-INJURED RATS

Rats pretrained to walk a narrow balance beam received unilateral sens orimotor cortex lesions, resulting in a contralateral transient paresi s that lasted 14 days. In a dose-dependent manner, a single injection of the antidepressant trazodone given 24 hours after injury transientl y slowed motor recovery compared with injured controls. After final re covery level of motor function, a reinjection of trazodone reinstated the hemiparesis for up to 6 hours. In other animals, a single injectio n of the antidepressant desipramine significantly facilitated motor pe rformance when compared with injured controls. Desipramine had no dele terious motor effect when administered to animals that had recovered o n the beam-walking task. These findings would suggest that the predomi nately noradrenergic neurotransmitter effects of desipramine may facil itate, and those of the predominately serotonergic trazodone may hinde r, the recovery of locomotor performance after cortical injury in rats . Further studies appear indicated, including applying these findings to the clinical setting.