STEROID RECEPTORS IN THE BRAIN

Abstract

Publisher Summary This chapter focuses on steroid receptors in the brain. Interaction between steroid hormones and specific receptor proteins in the cytoplasmic fraction of hormone responsive cells in the brain represent a crucial initial step in the mechanism of steroid hormone action. Receptor transformation or other forms of receptor activation can play an important role in the mechanism of steroid hormone action. In terms of their physicochemical properties and binding parameters, the cytoplasmic steroid hormone receptors in the brain are very similar to those in non-neural target tissues. The subsequent steps of the mechanism of steroid hormone action in the brain are similar to those in other target cells. The changes of nuclear binding in the hypothalamic regions are completely different from those in the uterus. Nuclear binding in the responsive hypothalamic tissues is very high in the ovariectomized animals, compared to that in any of the phases of the cycle. On the contrary, in the uterus, nuclear binding after ovariectomy is very low—similar to that found during the oestrus cycle.