PSYC62H3 Chapter Notes - Chapter 3: Acetylcholinesterase Inhibitor, Axon Hillock, Neurotransmission
Document Summary
Ion channels pores in a neuronal membrane that allow the passage of ions: excitatory postsynaptic potential (epsp) stimulus that depolarizes a local potential. Inhibitory postsynaptic potential (ipsp) stimulus that hyperpolarizes a local potential. If an epsp occurs, depolarization causes local na+ channels to open, allowing na ions to enter. Ionotropic receptor ion channel that opens when a matching neurotransmitter binds to a site on the channel: two hypothesis, lock and key complementary shape before neurotransmitter binds to receptor. Nt leaves the receptor stimulation: neuromodulation prevents ionotropic receptors since they have direct effects on the activity of a neuron. Table 3. 1 differences between ionotropic and metabotropic receptors. Physical proximity to parts of neuron where effects are exerted. Many use a g protein to activate ion channels and effector enzymes. Effector enzymes engage a cascade of events that persist after neurotransmitter leaves receptors. Can affect local potentials; also has other effects, including enzyme regulation, gene expression, and protein synthesis.
