Neurohormone

any of a group of substances produced by specialized cells (neurosecretory cells) structurally typical of the nervous, rather than of the endocrine, system. The neurohormones pass along nerve-cell extensions (axons) and are released into the bloodstream at special regions called neurohemal organs. Neurohormones thus constitute a linkage between sensory stimuli (events or conditions perceived by the nervous system) and chemical responses (endocrine secretions that act on other tissues of the endocrine system or on tissues of other systems, such as those involved with excretion or reproduction).