PSYC 363 Lecture Notes - Lecture 3: Limulus, Amacrine Cell, Retina Horizontal Cell
Document Summary
Neural processing = interaction of signals of many neurons. Lateral inhibition = inhibition that is transmitted across the retina. Limulus demonstrated how lateral inhibition can affect the response of neurons in a circuit. Photoreceptors are much larger in horseshoe crab ommatidia = hundreds of tiny structures in the limulus. Each contains a lens & located directly over a receptor. Each lens and receptor is the size of a pencil point (large compared to human) Size made it possible to illuminate and record from a single receptor without illuminating other receptors. Found 2 things: light stimulus on a single receptor a= increase firing receptor a, light stimulus on neighboring receptors b as well= decrease firing receptor a. Due to lateral inhibition that is transmitted from b to a across eye of limulus by the fibers of the lateral plexus. 2 cells of the retina responsible for lateral inhibition: horizontal cells, amacrine cells. Horizontal cells send inhibitory signals to neighboring cells.