Recent advances in the neurochemical pathology of Alzheimer's disease. Studies of neuropeptides, cholinergic function and Alzheimer's disease-associated protein.

Our findings from three postmortem tissue studies in Alzheimer's disease (AD) are presented. We investigated (1) alterations in somatostatin (SRIF) and corticotropin-releasing factor (CRF) in AD; (2) regulatory changes in presynaptic cholinergic function in AD; and (3) use of Alzheimer's disease-associated protein (ADAP) as a diagnostic test for AD in postmortem tissue. Taken together, these findings reveal marked reductions in SRIF and CRF concentrations in many cerebrocortical areas in AD, a marked up-regulation of cholinergic neuronal activity in surviving cholinergic neurons in AD, and excellent specificity and sensitivity for the use of the ADAP assay as a diagnostic test for AD in postmortem tissue.