Hypothalamic and preoptic area alpha 1-receptor concentrations decrease, and cerebral cortical alpha 1-receptor...

alpha 1-Receptors were measured in intact male guinea pigs during the course of postnatal development. Receptor concentrations were significantly higher at day 1 in hypothalamus and at days 1 and 14 in preoptic area than at day 60. Conversely, in cerebral cortex, receptor concentrations were significantly lower in neonatal animals than in 60-day-old animals. There was no change in affinity of the receptor during development. Castration has no apparent effect on alpha 1-receptor concentration in any brain area.