the SFO has many efferent projections. In fact, SFO neurons have been experimentally shown to broadcast efferent projections to regions involved in cardiovascular regulation including the lateral hypothalamus with fibers terminating in the supraoptic (SON) and paraventricular (PVN) nuclei, and the anteroventral 3rd ventricle (AV3V) with fibers terminating in the VOLT and the median preoptic area. It seems that the most essential of all these connections is the SFO’s projections to the paraventricular hypothalamic nucleus. Based on their functional relevance, the SFO neurons can be branded as either GE, featuring nonselective cation channels, or GI, featuring potassium channels. While the afferent projections of the SFO are considered less important than the various efferent connections, it is still notable that the subfornical organ receives synaptic input from the zona incerta and arcuate nucleus. Study of subfornical organ anatomy is still ongoing but evidence has demonstrated slow blood transit time which may facilitate the sensory capability of SFO, enabling increased contact time for blood-borne signals to penetrate its permeable capillaries and influence regulation of blood pressure and body fluids. This observation coincides with the fact that SFO neurons have been shown to be intrinsically osmosensitive. Finally, it has been established that SFO neurons maintain resting membrane potential in the range of -57 to -65 mV. Function The subfornical organ is active in many bodily processes including, but not limited to, osmoregulation, cardiovascular regulation, and energy homeostasis. In a study by Ferguson, both hyper- and hypotonic stimuli facilitated an osmotic response. This observation demonstrated the fact that the SFO is involved in the maintenance of blood pressure. Featuring an AT1 receptor for ANG, the SFO neurons demonstrate an excitatory response when activated by ANG, therefore increasing blood pressure. The induction of the drinking response via the SFO can be antagonized, however, by the peptide, ANP. Additional research has demonstrated that the subfornical organ may be an important intermediary though which leptin acts to maintain blood pressure within normal physiological limits via descending autonomic pathways associated with cardiovascular control. Recent research has focused on the subfornical organ as an area particularly important in the regulation of energy. The observation that subfornical neurons respond to a wide range of circulating energy balance signals, and that electrical stimulation of the SFO in rats resulted in food intake supports the SFO’s importance in energy homeostasis. Additionally, it is assumed that the SFO is the lone forebrain structure