01:146:245 Lecture Notes - Lecture 10: Medial Geniculate Nucleus, Auditory Cortex, Tonotopy

• School: Rutgers University
• Department: Cell Biology and Neuroscience
• Course: 01:146:245
• Professor: Professor Wilhelms

Document Summary

~there are parallel auditory pathways for midbrain (colliculus) and hindbrain (brain stem) But for any ascending auditory info to get to cortex (forebrain), it needs to pass through thalamus. Specifically, needs to relay through medial geniculate nucleus (mgn) in thalamus. ~most input to mgn is from inferior colliculus, some from lower brainstem. ~mgn has neurons selective for different combinations of frequencies and time spacing of sounds. ~ultimate target for afferent auditory info is cortex at temporal lobe. ~in the cortex, there is primary area and belt (periphery) area. ~a1 has a precise tonotopic map because it gets point-to-point input from ventral mgc. ~in the tonotopic map is a striped arrangement of binaural strips. One strip has neurons excited by both ears called ee. Other strip has neurons excited by one ear and inhibited by other ear called ei. ~there are isofrequency bands in a1, neurons in each band respond specifically to their frequency range.