Postnatal maturation of cholinergic markers in forebrain regions of C57BL/6 mice

The maturation of some neurochemical markers linked to cholinergic function (choline acetyltransferase, acetylcholinesterase, muscarinic binding sites) has been studied from 10 to 150 days of age in mice belonging to C57BL/6 strain. Previous studies had suggested that part of the cholinergic neurons of the basal forebrain undergo degeneration during juvenile stages of life in these rodents. Our data showed a delayed maturation of the cholinergic levels in the cortex and hippocampus, the main targets of the forebrain cholinergic neurons, but not in the striatum and superior colliculus. In none of these regions was any clear trend towards a decrement of cholinergic levels observed during the lifespan considered. In the medial septum-diagonal band area, an actual decrease of cholinergic levels was observed between 60 and 150 days of age. A side experiment based on daily administration of GM1 ganglioside during juvenile life, showed no effect of this treatment on the maturation of cholinergic markers.