NEOCORTICAL INFARCTION IN SUBHUMAN PRIMATES LEADS TO RESTRICTED MORPHOLOGICAL DAMAGE OF THE CHOLINERGIC NEURONS IN THE NUCLEUS BASALIS OF MEYNERT

The aim of the present study was to investigate the long-term effect o f cortical infarction on the subhuman primate (Cercopithecus aethiops) basal forebrain. The lesion, carried out by cauterizing the pial bloo d vessels supplying the left fronto-parieto-temporal neocortex, induce d retrograde degenerative processes within the ipsilateral nucleus bas alis of Meynert. The morphometrical analysis revealed that significant shrinkage of cholinergic neurons and loss of neuritic processes were localized within the intermediate regions of the nucleus basalis. The average cross-sectional areas of choline acetyltransferase-immunoreact ive neurons in the intermedio-ventral (Ch4iv) and intermedio-dorsal (C h4id) nucleus basalis were decreased to 62.5 +/- 9.5 and 58.0 +/- 8.6% , respectively, of the sham-operated values. Although an apparent loss of Nissl-stained magnocellular neurons in Ch4iv and Ch4id was found b y applying a quantitative analysis based on a perikaryal-size criterio n, data obtained by the quantification of immunostained material faile d to reveal any significant decrease of cholinergic cell density. Resu lts are discussed in view of future application of this ischemic model to study processes of retrograde degeneration following cortical targ et removal and to assess potential neurotrophic and neuroprotective pr operties of pharmacologic agents.