Lecture -organization of cerebral cortex Flashcards
numerical data cerebral cortex
- 600g
- 2200 cm2
- 1/3: outer surface
- 2/3: hidden in sulci
- 10-15 billion neurons, 50 billion glial cells
- thickness: 1.5mm to 4.5mm
Isocortex
- also called neocortex, 95% of cerebral cortex
- 6 horizontal layers
- phylogenetically most recent part (M1, V1, STS)
Allocortex
- thinner
- 3 layers
columns
-neurons in layers connect vertically -> form columns
-small microcircuits
-example: ocular-dominance columns: visual info
-
how to visualize cortical columns
- fMRI
- Staining
association fibers
-connecting cortical areas within same hemisphere
commissural fibers
-connecting cortical areas of both hemispheres via corpus callossum
projection fibers
-connecting cortex with lower parts of the brain and spinal cord
fibers can be imaged using…
DTI- diffusion-tensor imaging
efferent fibers
-corticocortical fibers
- projection fibers
- > to thalamic nuclei
- > to basal ganglia
- > to brainstem
- > to spinal cord
sensory cortex
- multiple brain regions at which sensory info is received and processed
- tast: gustatory cortex
- smell: olfactory cortex
- hearing: auditory association area
- vision
- touch:
somatosensory cortex
- s1
- s2
- somatosensory association area
premotor area
-Brodmann area 6
-
supplementary motor area
-medial surface of BA 6
-somatotpoic organization (less precisely organized)
-
frontal eye field
- BA 8
- voluntary tracking of movement
