(23A) Cortex

Question 1

3 layered part of cortex

Answer 1

allcortex

Question 2

3-5 layered part of cortex

Answer 2

mesocortex

Question 3

6 layered part of cortecx

Answer 3

isocortex

Question 4

describe the cellular composition of the 6 layers of the cortex

Answer 4

I = cell poor; GABA interneurons
II, III = superficial pyramidal 
VI = granular 
V = deep pyramidal
VI = polymorphic

Question 5

What are the primary NTs of the pyramidal cells? Are the bipolar or multipolar? spiny or aspiny?

Answer 5

excitatory = glu, asp
bipolar (usually projection)
spiny

Question 6

What are the primary NTs of the nonpyramidal cells? Are the bipolar or multipolar? spiny or aspiny?

Answer 6

inhibitory = GABA
multi or bi polar but are local interneurons
aspiny

Question 7

nonpyramidal, multipolar cells that have terminations that surround the somas of pyramidal cells

Answer 7

basket cells

Question 8

nonpyramidal, multipolar cells that have terminations that contacts the initial segment of pyramidal cells

Answer 8

chandelier

Question 9

what subtype of nonpyramidal cells innervatet he more distal dendrites of pyramidal neurons

Answer 9

bipolar/bi-tufted

Question 10

what is the main extrinsic input to the cortex?

Answer 10

thalamus > widely ptojecting brainstem nuceli (which is modulatory)

Question 11

what layer of the cortex does specific thalamic input project to?

Answer 11

IV

Question 12

What later do non-specific thalamic inputs project to?

Answer 12

I

Question 13

What are the cortical inputs that project to ipsilateral cortex called? what layer of cortex are they found?

Answer 13

association fibers; II, III

Question 14

What are the cortical inputs that project to contralateral cortex called? what layer of cortex are they found?

Answer 14

callosal projections; II and III

Question 15

Where do pyramidal cells in cortex layers V and VI project?

Answer 15

superficial V = contralateral cortex or striatum
deep V = beyond telenchephalon (pons, brainstem, spinal cord)

VI = thalamus (same area that afferents came from)

**note I and IV receive inputs from non-specific and specific thalamic nuclei respectively

Question 16

Thalamocortical rhythms are observed on

Answer 16

EEG

Question 17

Why are chandelier cells powerful regualators of cortical output?

Answer 17

they synapse as AIS and therefore will determine the final size of the AP

Question 18

Why are basket cells powerful regualators of cortical output?

Answer 18

they are acting at soma and therefore will mooulate the signal leaving the body to the axon

Question 19

describe how a signal gets to and leaves the cortical column

Answer 19

comes in from thalamus to layer I or IV where they synapse with dendrites of cells that originate in layer II or III. these cells send their axons to layers V or VI to go to subcortical area of interest

Question 20

how does the cortical histology vary from motor to sensory cortex?

Answer 20

motor: little IV and big V; agranular
sensory: big IV and little V; granular

Question 21

brodman’s areas for primary motor and where is it found?

Answer 21

4

precentral

Question 22

brodman’s areas for primary sensory and where is it found?

Answer 22

3, 2, 1

postcentral, superior parietal lobule

Question 23

brodman’s areas for primary visual and where is it found?

Answer 23

17

banks of calcrine fissure

Question 24

brodman’s areas for primary auditory and where is it found?

Answer 24

41, 42

transverse gyri

Question 25

in general what happens in the assocaition areas

Answer 25

unimodal inputs get combined to paint a bigger picture of what is going on

Question 26

example of unimodal motor assc area (and Brodman #)

Answer 26

pre motor = 6

Question 27

example of unimodal somatoesthesis assc area (and Brodman #)

Answer 27

5 and 7

Question 28

describe where a somatosensory afferent from the VPL will go for processing in the cortex

Answer 28

VPL → 3, 2, 1 (parallel processing) → 5, 7 → heteromodal area to combine

Question 29

What is an evoked potential

Answer 29

mapping out somatosensory pathways by electrically stimulating surface of head and waiting in EEG for changes in specific area that controls it

Question 30

What may cause phantom limb?

Answer 30

cortical reorganization; due to loss of input after amputation, adjacent cells in the cortex take over the area that was previous devoted to the amputated limb and can result in referred sensations

Question 31

assc cortex that is imp for being able to pay attention

Answer 31

parietal assc cortex

Question 32

assc cortex that is imp for being able to name things

Answer 32

temporal

Question 33

assc cortex that is the overall executive of behavior

Answer 33

prefrontal = RIO = restriant, initiative, order and gives you sense of self

Question 34

assc cortex that is primarily involve in visual system

Answer 34

occipital

Question 35

assc cortex that primarily received input from pulvinar

Answer 35

parietal and occipital = attention and vision

Question 36

assc cortex that primarily received input from LP nucleus of thalamus

Answer 36

temporal = name things

Question 37

assc cortex that primarily received input from medial dorsal nucleus

Answer 37

prefrontal = execute behaviors

Question 38

effect of damage to paretal assc cortex on dominant side? non-dominant side?

Answer 38

dominant side = language disorder non-dominant = sensory neglect (ignore everything fond on contralateral side relative to the injury)

Question 39

effect of damage to temporal assc cortex

Answer 39

inability to recognize objects and people

Question 40

effect of damage to prefrontal assc cortex

Answer 40

personality changes and inability to plan

Question 41

responsible for providing your working memory

Answer 41

dorsolateral prefrontla cortex