D-AMPHETAMINE ATTENUATES DECREASED CEREBRAL GLUCOSE-UTILIZATION AFTERUNILATERAL SENSORIMOTOR CORTEX CONTUSION IN RATS

Unilateral contusion injury to the sensorimotor cortex causes, among o ther symptoms, a transient contralateral hindlimb hemiparesis in rats. A single i.p. 2 mg/kg dose of d-amphetamine (d-AMPH) 24 h after injur y accelerates spontaneous recovery from this particular deficit. The m echanism(s) of spontaneous and d-AMPH enhanced recovery are unknown bu t alleviation of a neuronal depression has been proposed. This quantit ative CMRglu study a as designed to determine effects of cortical cont usion injury and d-AMPH on CMRglu in cortical and subcortical structur es. At 2 days after injury, CMRglu was significantly reduced compared to sham-operated controls only in structures ipsilateral to contusion. Affected structures included the caudate putamen, medial geniculate n ucleus, lateral geniculate nucleus and the parietal cortex immediately posterior to injury. By 6 days post-contusion the hypometabolism part ially reversed in all structures. A single low dose of d-AMPH signific antly alleviated the post-traumatic CMRglu reduction at 2 days after i njury. Importantly, while this alleviation was nut significant for any single structure, the main effect of treatment was highly significant . d-AMPH increased CMRglu at 2 days post-injury by 18-33% compared to contused/saline-treated rats. These results suggest that alleviation o f neuronal metabolic depression may contribute to spontaneous and d-AM PH enhanced recovery. (C) 1997 Elsevier Science B.V.