HORMONES AND SEX-SPECIFIC BRAIN DEVELOPMENT

Abstract

Publisher Summary This chapter focuses on hormones and sex-specific brain development. The gonadotropin-releasing hormone (GnRH) is secreted under the influence of neurotransmitters. It is transported by the hypothalamo–hypophysial portal vessels to the anterior hypophysis, stimulating there the secretion of gonadotropins. The gonadotropins control the generative and vegetative function of the gonads. The gonadal hormones, in turn, exert either only an inhibitory or also a stimulatory, which is a positive feedback effect on gonadotropin secretion, depending on sex hormone levels during a critical pre- or perinatal period of brain differentiation and during a postpuberal priming period of brain function. Prenatal stress, which can lead to abnormal sex hormone levels and/or abnormal neurotransmitter metabolism in the developing brain, can represent a risk factor for the etiogenesis of sexual deviations in later life. The evocability of a positive estrogen feedback effect is dependent on the sex hormone levels during a critical differentiation phase and functional phase of the brain. In case of a low androgen level during the differentiation period, a relatively strong positive estrogen feedback action on LH secretion can be elicited after estrogen priming during the functional phase.