cerebral cortex

Question 1

Which areas of cortex are “agranular” and general function

Answer 1

motor and premotor cortex only- pyramidal layers are prominent, mostly concerned with output

Question 2

Which areas of cortex are “granular” and general function

Answer 2

Primary visual cortex- afferent/sensory characteristcs due to high amounts of granular cells

Question 3

Describe ascending pathway of cortex

Answer 3

Input to layer 4 granular cells>internal relay to layer 3 and 2 > output to layer 4 >

Question 4

Describe descending pathway of cortex

Answer 4

Layers 5 and 6 > output to layers 5,6, and 1

Question 5

Which layer of cortex is motor output layer

Answer 5

layer 5- output from motor cortex to spinal motor neurons occurs entirely from layer 5

Question 6

What does the EEG measure

Answer 6

Electrical potential fluctuations at the scalp surface, produced mainly by temporal and spatial summation of
electrical currents caused by the relatively slow postsynaptic potentials (EPSPs and IPSPs) induced in neurons of the cerebral cortex (note there is relatively little contribution of the comparatively brief action potential to the EEG signal).

Question 7

Where does summation of electrical potentials occur in cortex

Answer 7

at pyramidal cells

Question 8

Why do EEGs show up as distinct oscillations rather than random noise

Answer 8

Neuron activity is synchronized

Question 9

Mechanisms of neuronal synchronization in cortex

Answer 9

conductor-led (ie. thalamic reticular nucleus’ control over thalamocortical info) and self organizing (co-firing of interneurons by chance)

Question 10

minicolumns and macrocolumns

Answer 10

Minicolumn: A cylinder corresponding roughly to the dendritic tree of a single layer 5 pyramidal cell, extending through six cortical layers. Macrocolumn: Bundle of minicolumns