Abstract: Effects of inhibition of catecholamines biosynthesis on learning insocially isolated rats were investigated. Both gregarious rats and isolatedrats were divided into α-MT,DDC and control groups, It was foundthat more training was required in the learning of positional watermaze for isolated rats after α-MT injection (250mg/kg, ip), but not sofor gregarious rats. No significant effects of DDC (500mg/kg, ip) on thelearning of positional water maze were observed both in isolated andgregarious rats. A decrease of 38% in cerebral cortex (including hippocampus) con-tents of noradrenaline was observed in isolated rats after α-MT injection,and only a decrease of 20% in gregarious rats. These results suggestthat the decrease of learning ability. in isolated rats is related to thedecrease of brain contents of catecholamines, particularly the contentsof noradrenaline in the cerebral cortex.

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