Effect of S-adenosyl-L-methionine (SAMe) on disturbances in hand movement and delayed response tasks after lesion of motor or prefrontal cortex in the monkey

Abstract

Effects of SAMe on disturbances in trained hand movement tasks or a trained delayed response task after lesion in unilateral motor cortex (hand area) or bilateral dorsolateral prefrontal cortices were studied in the monkey. Following lesion, hand movement tasks or delayed response tasks were disturbed moderately or severely for one week to several months depending on the extent of lesion or nature of task. Although treatment with small doses of SAMe (10 mg/kg/day, i.m.) had no effect, treatment with moderate doses (SAMe, 20 or 30 mg/kg, i.m.) reduced impairment and promoted recovery from both disturbances. Even in the chronic stage (76-140 days after operation), SAMe (30 mg/kg/day, i.m.) facilitated recovery from delayed response deficits. Histological findings in the acute stage after cortical lesion in rats showed that SAMe (50 mg/kg/day, s.c.) augmented infiltration of activated phagocytic macrophages in lesioned sites. Data suggest that SAMe improves recovery from behavioral and histological disturbances due to brain damages.