Abstract
Total opioid binding and levels of the three major types of opioid binding sites were measured in homogenates of various limbic structures from post-mortem brains of Alzheimer's disease patients and age-matched control individuals. The most consistent finding in Alzheimer's disease brains was an increase in ϰ binding in all 6 areas of the limbic system examined, with the putamen and caudate regions showing significant increases of 114% and 53%, respectively. In addition, the Alzheimer's disease putamen showed a significantly higher level of total binding (85% increase). The amygdala of Alzheimer's disease patients exhibited significantly lower levels of μ and δ binding (41% and 55% decrease, respectively). Total binding and binding to μ and δ receptors in frontal cortex, caudate and hippocampus of Alzheimer's disease brains was indistinguishable from levels seen in these brain areas from control individuals.
