HIGH-AFFINITY NEUROTROPHIN RECEPTORS IN CHOLINERGIC NEURONS IN THE HUMAN BRAIN

Tyrosine protein kinases TrkA and TrkC are signal-transducing receptor s for nerve growth factor (NGF) and neurotrophin-3 (NT-3) respectively . In the human brain postmortem, using sequential immunohistochemistry , we detected the presence of TrkA and TrkC on 99% and 95% of choliner gic neurons from the basal forebrain and on some cholinergic neurons ( 22% and 16%, respectively) from the striatum, but not on those from th e mesencephalon. These results suggest that some cholinergic neurons, particularly those of the nucleus basalis of Meynert, may be sensitive to both NGF and NT-3 in the human brain. The sensitivity of cholinerg ic neurons to these two neurotrophins may have a special interest in t herapeutic strategies for Alzheimer's disease.