[Neurocyte reaction of the anterior and mediobasal hypothalamic nuclei in birds to testosterone propionate].

Some magnocellular and parvocellular hypothalamic nuclei of cockerel were studied for their reactivity to testosterone-propionate (TP). It has been ascertained that injections of 1 or 5 micrograms/100 g doses of TP activate the neurocytes of preoptic periventricular and tuberal nuclei. This effect is manifested between 45th and 60th day of life and may be regarded as an early event of sexual maturation.