Age associated decrements in dopamine D-2 receptors in thalamus and in temporal insula of human subjects

[摘要] This study evaluates the effects of age on DA D-2 receptors in extrastriatal regions. DA D-2 receptor availability was evaluated in 42 healthy male subjects (mean age 41 +/- 16, range 21 - 86 year old) with positron emission tomography (PET) and [C-11]raclopride. Estimates of B-max/K-d were obtained using the ratio of the distribution volume in the region of interest (caudate, putamen, thalamus, frontal, occipital cortices, temporal insula, cingulate and orbitofrontal gyri) to that in cerebellum. Correlations between age and D-2 receptors were significant in putamen (r = -0.58, p less than or equal to 0.0001), caudate (r = -0.54, p less than or equal to 0.0002), thalamus (r = -0.33, p less than or equal to 0.03) and temporal insula (r = -0.39, p less than or equal to 0.01) but not in any of the frontal regions. The decrease in DA D-2 receptor availability was 6.6% per decade in caudate, 8.2% in putamen, 7.6% in thalamus and 13% in temporal insula. This study indicates that D2 losses with age are not limited to striatum and involve also thalamic as well as temporal cortical regions.

[发布日期] 1996-05-31

[关键词] aging;extrastriatal dopamine receptors;[C-11]raclopride;positron emission tomography