L33 Psych 330 Lecture Notes - Lecture 1: Retinal Pigment Epithelium, Ciliary Muscle, Optic Chiasm
7 Apr 2016
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Document Summary
The basis of the representations in the brain. Receptor cells are specialized neurons that don"t have dendrites. Instead, they transduce physical energy in to electrical energy (vs. transmitting it) This is how neurons communicate -- one neuron doesn"t directly touch the next neuron -- there"s a small gap called synapse. Neurons transmit information via electrical signals, but electrical signals are generated by chemical changes. Voltage inside neuron is -70 mv with respect to outside surroundings = resting potential. Caused by imbalance in ions inside/outside of cell. K+ insdie cell (when cell is at rest) When neuron receives input from another neuron, permeability of the cell membrane changes, allowing na+ to flow in. The influx of positively charged na+ increases the potential (voltage) inside the cell. This is followed by an outflow of k+, which then decreases the voltage back to resting level. There"s no such thing as a small/medium/big action potential -- either happens or doesn"t.
