PSYCH 15 Lecture Notes - Lecture 5: Inhibitory Postsynaptic Potential, Membrane Potential, Resting Potential
Document Summary
10/6/16: lecture 5: neural conduction and synaptic transmission. The arrival of action potential at a terminal opens voltage-activated ca2+ channels. Entry of ca2+ causes vesicles to fuse with terminal membrane and release their contents. Membrane potential: difference in electrical charge between inside and outside of cell. Inside is negative with respect to outside (resting potential: -70 mv) Negatively charged proteins (a-)--synthesized within and found primarily in the neuron (*) electrical gradient pulls k+ in, concentration gradient pulls. Result: small flow of k+ out (**) keeps k+ in, na+ out. Ligand-gated: opens only if correct neurotransmitter binds (lock-and-key) Opens only if cell membrane depolarized to a specific threshold. Neuron will not fire if depolarization is below threshold. Opposite of epsp: inhibitory postsynaptic potential (ipsp) Chloride channels (1) na+ channels open, na+ enters cell. Ligand-gated first, then voltage- gated ones follow one by one (action potential) (2) k+ channels open, k+ leaves cell.
