The supraoptic nucleus in the pig hypothalamus: postnatal development and the effect of gonadal steroids

Postnatal development of the supraoptic nucleus (SON) in the pig hypothalamus was studied morphometrically. The volume of the SON increased from 6.2±0.45 (S.E.M.)mm 3 at 7 weeks postnatally to 18.5±1.35 mm 3 at 2.5 years of age. A sex difference was found at the development point when the SON volume increased, with earlier SON enlargement in males. This sex difference was 30% at 30 weeks and 50% at 1 year of age. At 2.5 years of age no difference in volume was apparent between the sexes