Invited Symposium: What Can Genetic Models Tell Us About Attention-Deficit Hyperactivity Disorder (ADHD)?
Teicher, MH (Department of Psychiatry, McLean Hospital and Harvard Medical School, USA)
Gender effects the overproduction and elimination of dopamine receptors during adolescence in the ascending dopamine systems of rats. We found that while striatal male D2 receptor density increased 144 ± 26% between 25 and 40 days (the onset of puberty), female D2 receptor density increased only 31 ± 7%. Male receptor density was then sharply eliminated by 55% by adulthood. Females showed little overproduction and pruning of striatal D1 and D2 receptors, though adult density was similar to males. Cortical dopamine receptors declined by adulthood in males in a more dramatic and protracted pattern than striatum. D2 receptor density did not change appreciably in the accumbens of either sex between 40 and 120 days; however, D1 receptor density was significantly higher in males than females in adulthood. Gender differences in ADHD may be attributable to gender differences in dopamine receptor density. The rise of male, but not female, striatal dopamine receptors parallels the early developmental appear ance of motor symptoms of ADHD and may explain why prevalence rates are 2-4 fold higher in men than women. Pruning of striatal dopamine receptors coincides with the estimated 50-70% remission rate by adulthood. More persistent attentional problems may be associated with the overproduction and delayed pruning of dopamine receptors in prefrontal cortex. Differences in D1 receptor density in nucleus accumbens may have implications for increased substance abuse in males.
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|Andersen, SL; Teicher, MH; (1998). Sex Differences In Dopamine Receptors And Their Relevance To ADHD. Presented at INABIS '98 - 5th Internet World Congress on Biomedical Sciences at McMaster University, Canada, Dec 7-16th. Invited Symposium. Available at URL http://www.mcmaster.ca/inabis98/sadile/andersen0346/index.html|
|© 1998 Author(s) Hold Copyright|