PSL300H1 Lecture Notes - Lecture 17: Acetylcholine, Endorphins, Second Messenger System
Document Summary
The type of receptor determines the downstream response, not the nt. Receptor specificity determines the effect of that neurotransmitter! Opens ion channels: na+ in, k+ out, or cl- in. Excitable post-synaptic potential (epsp: na+ out depolarization of membrane. Ipsp: k+ in, cl- in hyperpolarization. Duration of response: dependent on length of time the nt is bound to receptor, usually around 20-40ms. Acetylcholine (w/ nicotinic receptor), glutamate, gaba, glycine. Slower requires the recruitment/production of secondary messengers & other cellular components. Activates secondary messenger: camp, cgmp, ip3. Secondary messengers effects: activate other enzyme modify existing proteins, metabolic effect, phosphorylate membrane proteins opens/closes channel, modulating ions. Gpcr adenylyl cyclase camp production phosphokinase a: pka phosphorylates ca2+ channels ca2+ influx. Ach (w/ muscannic receptor), adh, -endorphins, substance p, Cell body conducts the current: cannot generate ap"s, does not have voltage-gated na+ channel. Passive conduction of currents axon hillock (trigger zone: weakens through diffusion.
