Comparative postnatal development of dopamine D₁, D₂ and D₄ receptors in rat forebrain

Postnatal development of dopamine D(1), D(2) and D(4) receptors in the caudate-putamen, nucleus accumbens, frontal cortex and hippocampus was assessed in rat brain between postnatal days 7 and 60. In the caudate-putamen and nucleus accumbens, density of all three receptor subtypes increased to a peak at postnatal day 28, then declined significantly in both regions (postnatal days 35-60) to adult levels. In the frontal cortex and hippocampus, these receptors rose steadily and continuously to stable, maximal adult levels by postnatal day 60. Evidently, D(1), D(2) and D(4) receptors follow a similar course of development in several cortical, limbic and extrapyramidal regions of rat forebrain, with selective elimination of excess dopamine receptors at the time of puberty in the caudate-putamen and accumbens but not other brain regions.