Alzheimer's disease. Aminergic-cholinergic alterations in hypothalamus

To better understand the role of the hypothalamus in Alzheimer's disease (AD), we have measured dopamine, norepinephrine (NE), and serotonin (5HT) levels, tritiated spiperone and tritiated serotonin blinding, and choline acetyltransferase (ChAT) and acetylcholinesterase activity in seven subregions of the hypothalamus from 18 normal control subjects and ten patients with AD. We have found a significant reduction of 5HT in the anterior hypothalamus, lateral hypothalamus, and posterior lateral hypothalamus and a decline in spiperone binding in the anterior hypothalamus of patients with AD. The ChAT activity was found to be diminished only in the posterior lateral hypothalamus of patients with AD. No NE or dopamine alterations were found in any region of the AD hypothalamus. In the normal hypothalamus, dopamine, NE, and 5HT were found to be regionally distributed. Our study documents region-specific neurotransmitter abnormalities in the AD hypothalamus and raises the question of the relationship of these changes, especially in 5HT, to some of the noncognitive clinical alterations observed in AD.