PSL300H1 Study Guide - Midterm Guide: Olfactory Bulb, Chemoreceptor, Gustducin
Document Summary
May-27-13 2:55 pm chemoreception olfactory neurons olfactory bulb olfactory projections stem cells odorant receptors and golf vemeronasal organ pheromones. Chemoreception evolutionary old. bacteria used it to guide their movements, aminals w/ no brain use it to find food + mates. Type iii cells form synapses with sensory neurons, activating them with serotonin. Type ii cells release atp acts on neurons and type iii cells. Type ii g protein-coupled receptors: sweet and umami involve t1r receptors, bitter t2r receptors . both associated with gustducin (g protein) which activates signal-transduction pathways increase intracellular [ca+], triggering release of atp (activates neuron, acting like nt). Salty + sour transdiction involves ion channels, not g-proteins. Na+ enters type i cells, through apical channel (epithelial na+ channel) depolarizes cell. Sour controversial, we know that something is activated in type iii cells, by h+ and serotonin is released. H+ may act on ion both on intra and extra cellular sides of membrane.
