PSY100H1 Lecture Notes - Lecture 5: Resting Potential, Methamphetamine, Basal Ganglia
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PSY100H1 Full Course Notes
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Neurons: basic unit, operate through electrical impulses and communicate with other neurons through chemical signals. Action potential: neural impulse, passes along axon and causes release of chemicals from terminal buttons. Resting potential: polarized stage (negative inside cell) Excitatory signals: increase likelihood that neuron will fire. All-or-none principle: fires with same potency each time (i. e. either fires or does not fire) Neurons polarized at rest (resting stage), more sodium outside and more potassium inside. Depolarization: if neuron reaches excitatory threshold, will fire/depolarize. Na+ channels open, charge across membrane reverses (more negative inside cell due to influx of na+) Peak action potential and hyperpolarization: at peak of action potential, na+ channels close, k+ channels open, so k+ can leave cell. Temporary hyperpolarization, cell cannot fire (refractory period) K+ channels close, cell returns to resting state. Neurotransmitters: chemical substances that carry signals from one neuron to another. Stored in vesicles (small packages) inside terminal buttons.
