[Neuromodulators and Alzheimer's disease]

Alzheimer's disease (AD) is one of more than 60 disorders that may produce dementia. It is characterized clinically by memory deficits and by the presence of aphaso-apracto-agnosic disorders. In the general population, AD has an incidence of 0.3 to 1% and is very common in the elderly (more than 50% of dementia cases). The pattern of pathological changes in the brain in AD is relatively specific. Neuritic plaques, neurofibrillary tangles and cell loss, occur primarily in the cerebral neocortex and hippocampus. On the other hand, neurochemical deficiencies related to the illness have now been identified. The vulnerability of the cholinergic system of the basal nucleus of Meynert was first documented. Following the discovery of the cholinergic reduction in AD and among a dozen of neurotransmitter systems involved in AD, somatostatin, substance P, neuropeptide Y, corticotropin releasing factor and amino acid glutamate were investigated and are the most affected in AD. Results of previous publications and our own investigations are presented here.