CMST 2060 Lecture : CMST Final Notes
Document Summary
Action potentials in optic nerve have 100,000 the energy of the photons of light that triggered them. Over time receptors stop responding to stimulus (ex: not being able to smell scents after a length of time) Different receptors communicate action potentials to different parts of the brain. There are about 1,000 different olfactory receptors which bind to different odorant molecules. (discovered by 2004 nobel prize winners richard axel and linda buck) Activate g-protein system, second messenger (camp) camp opens na+ channel in protein. Na+ ions moving into cell depolarizes the membrane. If the threshold is reached during depolarization, an action potential is triggered. Action potential is transmitted to olfactory lobe of the brain. For mixtures of odorants, there is integration of the signals, so the mixtures have unique odorant signatures. Mucous layers are thicker, covering more of the receptor cells. Channels in membrane transport na+ and ca2+ ions.
