Nervous system control over hormone release is based in the hypothalamus, from which the neurons that populate the pariventricular and arcuate nuclei originate.  These neurons project to the median eminence, where they secrete releasing hormones into the hypophysial portal system connecting the hypothalamus with the pituitary gland. There, they dictate endocrine function via the four Hypothalamic-Pituitary-Glandular axes.  Recent studies have begun to offer evidence that many pituitary hormones which have been observed to be released episodically are preceded by pulsatile secretion of their associated releasing hormone from the hypothalamus in a similar pulsatile fashion.  Novel research into the cellular mechanisms associated with pituitary hormone pulsatility, such as that observed for Leutinizing Hormone (LH) and Follicle Stimulating Hormone (FSH), have indicated similar pulses into the hypophyseal vessels of Gonadotropin Releasing Hormone (GnRH).