Nucleus basalis Meynert lesions and the expression of nicotinic acetylcholine receptor proteins in the rat frontal cerebral cortex.

An important feature of cholinergic dysfunction in Alzheimer's disease (AD) is the degenerative loss of magnocellular cholinergic neurons in the basal nucleus of Meynert. In search for suitable animal models of Alzheimer dementia, rats with lesioned basal nuclei rats have been shown to display learning and memory disturbances. We here report on the quantitative assessment of the expression of the nicotinic acetylcholine receptor alpha4 protein in the rat frontal cerebral cortex following a unilateral lesion of the basal nucleus. Cortical alpha4 isoform expression shows a significant increase on the lesioned vs. the non-lesioned control side 1 week after lesioning. By contrast, no differences were observed 4 weeks after lesioning. In consideration of these results basal nucleus lesions appear as a questionable model of AD which in contrast to the present findings shows a decrease of cortical alpha4 nicotinic acetylcholine receptor protein expression.