Topography of neurochemical alterations in the CNS of aged rats

We have performed a general survey study on alterations of neurotransmitter -related and glia-related neurochemical markers in various regions of the C NS of aged (30-month-old) as compared to adult (4-month-old) rats. We have found significant decreases in the level of neurochemical parameters relate d to the cholinergic and GABAergic systems in several regions of the CNS of aged rats. Only few of the alterations present at the age of 30 months, we re present in a group of rat of intermediate age (20 months) included in th e present study. Less widespread alterations were found concerning the glut amatergic neurotransmission system. Neurochemical markers related to glial cells (astrocytes and oligodendrocytes) showed a remarkable stability in ag ed rats as compared to neurotransmitter-related markers. Considering the va rious CNS areas examined in the present study, the spinal cord of the aged rats was the region showing the most profound alterations of neurochemical parameters, as compared to the various brain areas of the same rats. The pr esent results suggest that moderate and region-specific alterations of neur otransmitter-related parameters occur during normal aging and that glia-rel ated markers are fundamentally stable in the absence of specific pathologie s. (C) 2001 ISDN. Published by Elsevier Science Ltd. All rights reserved.