Major cell types of the cortex and their major function
- Granule cells - "sensory"
- Pyramidal Cells - "motor"
What is the name for:
1. motor cortical areas?
2. sensory cortical areas?
- 1. Agranular Cortex - mostly pyramidal cells
- 2. Granular Cortex - mostly granule cells
What are Brodmann's Areas?
- Organization of cortex into numbered areas
- Uses cell packing, density, thickness
How many laminae are their, and what are their cells types and functions?
- I - molecular layer (few cells)
- II - granule cells (sends info to other cortical regions)
- III - pyrimidal cells (sends info to other cortical regions)
- IV - granule cells (primary recipient zone of cortex)
- V - pyramidal cells (project out of cortex)
- VI - multiform (projects mostly to thalamus)
What is the difference between homotypical and heterotypical cortex?
- Homotypical - six layers are clear, higher cerebral function
- Heterotypical - increased granularity that makes layers difficult to distinguish, sensory cortex
What is the elemental function unit of the cerebral cortex?
From which thalamic nuclei does the Somatosensory Cortex recieve information?
VPLc and VPM
Which Brodman's Areas make up the Somatosensory Cortex and what are their individual responsibilities?
3a, 3b, 1, 2 - Postcentral Gyrus
- 1, 3b - cutaneous, discriminative touch
- 2, 3a - deep tissue and joint input
Where is Somatosensory Area II?
What is unique about this area?
- Superior bank of the lateral fissure
- Allows integration of information from both sides of the body
1. Where is pain localization and intensity determined?
2. Where are the affective/reactive components triggered?
1. SI, SII
2. Rostral insula, rostral cingulate cortex
What is plasticity of the Somatosensory Cortex?
- dramatic rearrangements after deprivation or alteration of somatic input
- ex. theory - phantom limb pain
2. Input from?
3. Tonotopic representation?
- 1. Transverse gyri of Heschl
- 2. From Medial Geniculate Body
- 3. low freq (ant/lat), high freq (post/med)
What are the neurotransmitters generally used by pyramidal and granule cells and why?
- Glutamate, aspartate
- Generally excitatory
What neurotransmitters are important in cortical arousal?
Acetylcholine and norepinephrine
Which neurotransmitter has a role in pain control/sleep?
Which neurotransmitter has an inhibitory role which sharpens sensory processing?
What symptom and condition is associated with reduction in its activity?
- Seizures and epilepsy