T2-WEIGHTED MRI STUDIES OF MOUSE LEMURS - A PRIMATE MODEL OF BRAIN AGING

Previous histological and behavioral studies of aging mouse lemurs hav e demonstrated changes similar to those observed in elderly humans and in patients with Alzheimer's disease. We explored 18 animals of ages 6 months to 9 years. Axial T2-weighted images of the brain were perfor med on a 4.7 Tesla Bruker Biospec 47/30 system. We estimated cerebral atrophy by adding measures of high signal areas characteristic of cere brospinal fluid (interlobular and sylvian fissures, lateral and third ventricles) of four contiguous cortical slices. We observed a signific ant increase of cerebral atrophy with aging and one case of an apathet ic 8-year-old animal presenting a considerably higher cerebral atrophy . We also observed high correlations between decreased signal intensit ies and age for the pallidum, the substantia nigra, and the putamen. T hese results suggest that aging mouse lemurs present similar magnetic resonance images of cerebral alterations to those encountered in aging humans and that high-field T2-weighted magnetic resonance images can help in the early detection, in vivo, of animals suspected of patholog ical aging. (C) 1997 Elsevier Science Inc.