NSC 4366 Lecture Notes - Lecture 3: White Matter, Microglia, Multiple Sclerosis
Document Summary
Synaptic cleft is a chemical reaction of communications. Resting potential (membrane potential: stays -70 milivolts, inside negative compared to outside, na+ channels closed, k+ channels open, k+ wants to go out, na+ wants to move in, but can"t. Action potential (nerve impulse: how information is coded within neurons, change in electrical energy propagated from hillock along axon. Reversal of polarity of a neuron when it is stimulated or excited above threshold level. Propagated down axon and invade nerve terminals. Voltage gated sodium channel opens potassium rushes out, restoring the negative charge inside the cell (repolarization) Cause release of neurotransmitters: depolarize membrane move toward threshold for action potential production, hyperpolarize membrane stabilize cell. Cocentration gradient things move from high to low concentration: 2. Electrical forces opposites attract, like charges repel. Spread passively and the amplitude progressively decreases as it moves farther from origins. Summation at hillock to shoot or not shoot = excitatory postsynaptic potential (epsp) vs. inhibitory postsynapstic potential.
