NEUR3112 Lecture Notes - Lecture 27: Median Eminence, Area Postrema, Proopiomelanocortin
Document Summary
Better experiment -> optogenetics activating/inhibiting specific brain areas. Lots of connections to and from the brain step and hypothalamus. Median eminence and area postrema" have permeable blood brain barrier. Hormones (like insulin) can get in and directly activate neurons. Median eminence join the 2 sides of the brain. Arc -> the triangle shape near ivrd ventricle. Pomc pro-opiomelanocortin a precursor polypeptide (241 amino acids) Pomc cells are not just in this brain area -> also found elsewhere. Alpha-msh -> activates melano-cortical receptors (mcrs) -> of interest are mc3r and mc4r. For energy balance, production of -msh most important (melanocyte-stimulating hormone) [adrenocorticotropin (acth) and -endorphin have other important roles in body] Msh activates the melanocortin receptors (e. g. mc3r and mc4r) Agouti-related peptide (agrp) is an endogenous antagonist (or inverse agonist) at. It is only synthesised in npy neurons in the arc. Reduces energy expenditure -> not just specific to eating, but also activity.
