PSYC 100 Lecture 3: (3) Neuroscience & Behavior

• School: Simon Fraser University
• Department: Psychology
• Course: PSYC 100
• Professor: Russell Day

Document Summary

Neural transmission: action potentials / neurotransmitters / drug effects. More excitatory = fire, more inhibitory = doesn"t fire. All or nothing principle- once an action potential fires, it propagates the full length of the axon and the terminal buttons release neurotransmitters into the synapse. Interneurons can sum the information from many cells, resulting in a graded potential. Graded potential issue- could inhibit excitatory firing. Approaching nerve impulse causes the neurotransmitter molecules (in their vesicle) to be transmitted across the synaptic cleft. They will stimulate the next neuron if they are the right size on the postsynaptic membrane (neurotransmitter receptors) Can tell them to relax or tell them to not relax and not let any chemicals inside. Could be up to a trillion sites that this is happening. A neuron at rest will fire random action potentials. A stimulated neuron might increase/decrease its firing rate. Excitatory signals lead to depolarization in the post synaptic cleft.