NGF-MEDIATED SYNAPTIC SPROUTING IN THE CEREBRAL-CORTEX OF LESIONED PRIMATE BRAIN

In the present study, coronal brain sections of cortically devasculari zed non-human primates (Cercopithecus aethiops) were used to assess th e lesion-associated synaptic loss, and the effect of exogenous nerve g rowth factor (NGF) in preventing or reversing this neurodegeneration. The sections were immunolabeled with antibodies against the synaptic m arker protein synaptophysin (SYN), as well as choline acetyltransferas e (ChAT) and parvalbumin (PV) markers that identify cholinergic neuron s and interneurons, respectively. We found that, compared to sham-oper ated animals, in the lesioned vehicle treated animals SYN immunoreacti vity near the lesioned site in the frontoparietal cortex was decreased by 31%. Similarly, corrected optical density values of immunostained sections specific for ChAT in the nucleus basalis of Meynert (ipsilate ral to the lesion) decreased by 20% and PV-immunoreactive neurons near the lesion decreased by 47%. In contrast, NGF-treated lesioned animal s showed levels of SYN, ChAT, and PV immunoreactivity similar to sham controls. These results are consistent with previous studies and suppo rt the view that NGF may not only prevent neurodegenerative changes af ter neocortical infarction by protecting vulnerable neurons, but also is capable of inducing sprouting and synaptogenesis.