Perisomatic sprouts immunoreactive for nerve growth factor receptor and neurofibrillary degeneration affect different neuronal populations in the basal nucleus in patients with Alzheimer's disease

Abstract

Aberrant morphological profiles, most likely reflecting a process of perisomatic sprouting, have been detected in Alzheimer's disease (AD) on neurons of the basal nucleus of Meynert by means of Golgi impregnation. Using the mouse monoclonal antibody, ME 20.4., perisomatic profiles were shown to be immunoreactive for nerve growth factor receptor (NGFR). Double label studies using either thioflavin S or anti-neurofibrillary tangle (NFT) antibody B5 in combination with ME 20.4 demonstrated that neurons with aberrant growth profiles failed to express neurofibrillary tangle-bearing material, which otherwise could be detected in large amounts throughout the basal forebrain. The results indicate that in AD, neurons in the basal forebrain, not affected by neurofibrillary degeneration, respond to an increased trophic influence. Dendritic sprouting in AD might, therefore, more likely be regarded as an attempt by the nervous system to repair itself following damage rather than as an abnormal process with primary pathologic significance leading to cellular degeneration.