AGE-RELATED LOSS OF CALBINDIN FROM HUMAN BASAL FOREBRAIN CHOLINERGIC NEURONS

Loss of basal forebrain cholinergic neurons (BFCN) occurs in many age- related neurological diseases. Although age is the common risk factor in these disorders, no consistent age-related changes have been report ed in the human BFCN. We investigated age-related alterations in choli ne acetyltransferase (ChAT), low-affinity nerve growth factor receptor (p75(LNGFR)) and calbindin-D-28k (CalBP) immunoreactivity in the huma n BFCN. No significant age-related changes were observed in ChAT or p7 5(LNGFR) immunoreactivity. By contrast, normal aging was accompanied b y a selective, substantial and significant loss of CalBP immunoreactiv ity from the BFCN. Other CalBP-positive neurons were unchanged. Loss o f the calcium buffering capacity conferred by CalBP may leave the BFCN vulnerable to damage in neurodegenerative disorders.