PSYC 2200H Lecture Notes - Lecture 9: Potassium Channel, Chemical Synapse, Electrical Synapse
Document Summary
Gap junctions between axon of one neuron and dendrite of another neuron. These channels allow for charge to move back and forth between them. These gap junctions allow for ions to flow back and forth between the neurons. Action potential generates opening of calcium channels. Signal transfer occurs at the synapse ca2+ mediated exocytosis. Entrance of calcium allows the release of neurotransmitters. Filament proteins that connect presynaptic and postsynaptic neuron. Binding of neurotransmitters to the post synaptic membrane can either be: excitatory (produces epsp, depolarizes membrane potential (makes cell more positive) Lessening of the negative charge inside of the membrane. Gaba: both types of psps are graded potentials (as opposed to action potentials) What causes it to meet the threshold. Temporal summation occurs when two graded potential from the same synapse occurs close together in time. No summation: two subthreshold graded potentials will not initiate an action potential if they are far apart in time.