engleski

Lesions of the nucleus basalis in newborn, adult and ageing rats: effect on cortical ChAT activity and behavior

Experiments aimed to investigate the effect of nucleus basalis (NB) lesions on cortical cholinergic system and behaviour, spontaneous recovery and recovery induced by GMl ganglioside were carried out in rats of different age. Quisqualic acid unilateral lesions were placed in the NB of 14, 17 and 21-day old rats. A 50% decrease in choline acetyltransferase (ChAT) in the ipsilateral cortex was found 8 days after lesioning. A passive avoidance "step through" response was acquired by the sham operated 21-day old rats only. The 21-day old lesioned rats, sham operated and lesioned younger rats were unable to negotiate the test. Recovery 3 months after lesioning will be investigated. In 3-month old rats, with ibotenic acid unilateral or bilateral NB lesions, GMl ganglioside, 30 mg/kg i.p. for 20 days, beginning immediately after lesioning, reduces ChAT decrease and behavioral impairment. A 2 days treatment was ineffective. In 18-month old rats a unilateral ibotenic acid lesion was followed by behavioral impairment and an unexpected bilateral decrease in ChAT activity. GMl (30 and 60 mg i.p. for 20 days) reduced the contralateral ChAT decrease and behavioral impairment. Treatments of different duration and with NGF are presently carried out.

nucleus basalis lesions; choline acetyltransferase; age; rat

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