ANAT 321 Lecture Notes - Lecture 9: Franz Nissl, Golgi'S Method, Granule Cell

• School: McGill University
• Department: Anatomy & Cell Biology
• Course: ANAT 321
• Professor: David Ragsdale

Document Summary

Cortex differs in species due to surface area; not to neuron arrangement. Brain size generally proportional to animal size, but human anomaly (brain bigger compared to body) Brains not identical; but certain anatomical landmarks that are consistently identifiable. Diff regions separated by certain sulci have diff functions. Top is outside of cortex, bottom is inside. Molecular layer: not many cells; has synapses & dendrites. External pyramidal: pyramidal cells (cell body shaped like pyramids) Internal pyramidal: cells bigger than those in external pyramidal. Golgi stain: silver precipitate inside cells, define cell; only stains small fraction of neurons (random) Layer 4: receiver of thalamic inputs into cortex. Motor cortex is output, has many big pyramidal cells (output cells) Visual cortex receives inputs: many little granular cells. Pyramidal cells: output cells, large, 80% of neurons in cortex, excitatory (release glutamate) Granular cells: input, small, excitatory (glutamate), short axons. Inhibitory neurons: short axons, interneurons, gaba: feedback regulating excitation.