HMB200H1 Lecture Notes - Lecture 6: Tectospinal Tract, Superior Colliculus, Optic Nerve
Document Summary
Evolution of vertebrate brain: brains evolves for survival and reproduction (darwin) The tectum is a dome like structure that has direct inputs from the retina. If you go deeper into the perfondum layers: approach turns are activated by small stimuli in intermediate layers, deep layers respond to deep threatening layers that produce the turning away. Deep neurons have huge receptive fields frightened by large things: crossed and uncrossed outputs deep layers have uncrossed pathways which produce avoidance response. Superior colliculus anatomy: there is a deep layer. In the rat there is a map with 0 degrees being the midline: there is a 2d map going form dorsal to ventral, nasal to temporal. If you electrically stimulate the tectospinal pathway it will produce saccadic eye movements: stimulating the pathway makes the eyes turn to the direction in space it is mapped, an approach turn in the eye movement circuit.
