Differential functional ontogeny of dopamine presynaptic receptor regulation.

The ontogeny of dopamine (DA) presynaptic receptor regulation was examined neuropharmacologically in 7-, 14-, 21-, 28- and 35-day-old and adult rats. In striatum, gamma-butyrolactone (GBL) significantly increased DA levels as early as 7 days postnatally; apomorphine attenuated this increase beginning at 14 days postnatally. However, in olfactory tubercles, no increase in DA was observed after GBL until 21 days postnatally, and not until 35 days postnatally was apomorphine consistently able to attenuate this increase. Thus, DA presynaptic receptors in mesolimbic regions may mature several weeks later than in striatum.