Human and animal studies have indicated age-related declines in many behavioral functions, including motor activity, motivation, learning and short-term memory, sexual activity, food intake, and sleep. Aging has also been associated with an increased frequency in the occurrence of Parkinson's disease and senile dementia. It seems reasonable that these sequelae of aging have a neurochemical basis. In vitro studies of animal and human postmortem brains have revealed age differences in several neurotransmitters, in their associated enzymes, and in their receptors. Of particular interest is the reported age-related decline of D2 dopamine receptor density (but not affinity) in the striatum. The recent advent of specific chemical ligands labeled with positron emitting radioisotopes has allowed external imaging of some neurochemical markers in vivo by positron emission tomography (PET). PET permits noninvasive in vivo imaging of ligands specific for neurochemical elements such as receptors (in normal physiological states) and does this as a function of disease and therapy. We demonstrated the feasibility of in vivo visualization of neuroreceptors with the successful imaging of D2 dopamine and S2 seronin receptors in a normal adult using a potent ligand, (3-N-[11C]-methyl)spiperone ([11C]NMSP). We then began to assess possible age and sex differences in D2 dopamine receptors using this procedure.
|Original language||English (US)|
|Number of pages||11|
|Journal||Annals of the New York Academy of Sciences|
|State||Published - 1987|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)