PURINERGIC SIGNALING IN SENSORY SYSTEMS

Extracellular purines play multiple roles in a variety of sensory syst ems acting as neural signalling and humoral factors via purinoceptors. For example, ATP and adenosine have a neurosignalling role in autonom ic sensory-motor reflexes, mechanoreception and chemoreception mediate d via vagus nerve afferents, and in, nociception. Purinergic neuromodu lation of vision via adenosine in the retina is well established and t here is mounting evidence for a neuromodulatory role for ATP in the in ner ear. Humoral purinergic actions are found in the eye where adenosi ne clearly has an important vascular and humoral influence and in the inner ear where ATP probably regulates fluid homeostasis, hearing sens itivity and development. Clearly purinergic signalling underpins the p hysiology of many of the body's sensory systems. (C) 1996 Academic Pre ss Ltd