Effects of nimodipine on medial septal area cells after section of the fimbria-fornix

Abstract

In rats, sectioning the fimbria-fornix leads to a decrease in cells reactive for acetylcholinesterase and choline acetyltransferase, as well as other types of cells, in the medial septal area that project to the hippocampus. In this study cells in the medial septal area were stained for acetylcholinesterase reaction product or by a Nissl method two weeks after unilateral section of the fimbria-fornix. Counts were made of cells on each side of the midline by independent observers. The counts of the cells on the two sides of the brain were compared in rats that had been given nimodipine (70 μg/kg) just after the lesion and for 7 additional days and in rats that had been given only the vehicle for an equivalent amount of time. The number of cells reactive for acetylcholinesterase was reduced in the medial septal area on the side of the brain in which the forebrain fornix was sectioned, but this occurred to a significantly less extent in the nimodipine-treated rats. No differences were noted in the number of cells on the two sides of the medial septal area when counted in Nissl-stained sections.