Neuroendocrinology is one of the most important and prominent areas in biomedicine, and research in this integrative science has a profound impact on health and the pharmaceutical industry. It has been reported that sex steroid hormones play a key role in brain morphology and function, both in physiological and pathological conditions. Besides the regulation of processes directly involved in reproduction by sex hormones, it is evident that they participate in other brain functions not strictly related with reproduction such as neuroprotection, brain plasticity, and growth of cerebral tumors.