Cerebral Cortex

Question 1

What is the preferential site of excitatory synapses in pyramidal cells?

Answer 1

dendritic spines

Question 2

What is special about dendritic spines?

Answer 2

suggested sites of synapses that are selectively modified as a result of learning
- small changes in spine configuration lead to electrical properties and in turn synapse efficacy

Question 3

What do spiny stellate cells mainly receive?

Answer 3

most of afferent input from thalamus, other cortical areas

Question 4

What do smooth stellate cells do?

Answer 4

silence weakly active cell columns in cortex (similar to focusing action noted in cerebellar cortex by Golgi cells)

Question 5

Where are association fibers from?

Answer 5

long and short: from small and medium sized pyramidal cells in other parts of ipsilateral cortex

Question 6

Where are commissural fibers from?

Answer 6

medium sized pyramidal cells via corpus callous or anterior commissure from corresponding contralateral cortex

Question 7

Where are thalamocortical fibers from?

Answer 7

relay or association nuclei (VPL and VPM)

Question 8

Where are non-specific thalamocortical fibers from?

Answer 8

intralaminar nuclei

Question 9

Where are cholinergic and aminergic fibers from?

Answer 9

basal forebrain, hypothalamus (tuberoinfundibulum), brainstem (midbrain raphe, LC)

Question 10

Where do efferent commissural fibers come from?

Answer 10

contralateral cerebrum via corpus callous and anterior commissure

Question 11

What makes up the largest input to basal ganglia?

Answer 11

fibers from primary sensory and motor cortex

Question 12

What receives input from all of the cortex?

Answer 12

thalamus

- corticopontine, corticospinal, corticobulbar

Question 13

Association areas function?

Answer 13

mediate higher mental functions (language, art, music)

- not much known

Question 14

What do the parvocellular layers of the eye detect?

Answer 14

layers 3-6 (color and form)

Question 15

What do the magnoceelular layers of eye detect?

Answer 15

layers 1-2 (moment and contrast)

Question 16

Which layers get input from contralateral eye? ipsilateral?

Answer 16

1,4,6

2,3,5

Question 17

What did Dr. Tatsuji describe?

Answer 17

retinotopic organization of primary visual cortex

Question 18

Where do optic radiations end?

Answer 18

retinotopically in occipital cortex, above and below calcarine sulcus

Question 19

Where do inferior visual fields end? superior?

Answer 19

superior above calcrine sulcus

inferior below calcimine sulcus

Question 20

How is the macula represented? peripheral fields?

Answer 20

most posteriorly, more anteriorly

Question 21

Where does primary visual cortex distribute info?

Answer 21

specialized parts of extra striate cortex

Question 22

How do columns in cortical modules analyze info?

Answer 22

visual field

- modules in foveal part analyze small areas so fovea has many more modules and therefore better resolution

Question 23

Which hemisphere is determined to be dominant?

Answer 23

one that produces and comprehends language (usually L)

Question 24

Where are the cortical language areas near?

Answer 24

lateral sulcus

Question 25

What does the L lateral sulcus extend as making the hemispheres asymmetrical?

Answer 25

extends posteriorly as planum temporale

Question 26

What happens if you stimulate the motor cortex near the mouth? other areas?

Answer 26

• produce involuntary grunts, vocalization

- cease to speak but can still move mouth or make linguistic errors

Question 27

What is aphasia?

Answer 27

inability to use language, lose the use of or access to symbols humans use as concepts (words)

Question 28

What interconnects Broca’s and wernicke’s areas?

Answer 28

arcuate (sup longitudinal fasciculus)

- damage wernickes leave broca’s unchecked

Question 29

What language is in the R hemisphere?

Answer 29

prosody = musical aspects of speech

• R inf frontal gryrus produces prosody
• R post temporoparietal region comprehends prosody

Question 30

What is motor aprosody? sensory?

Answer 30

motor = can't convey authority, anger, etc in speech 
sensory = difficulty comprehending emotional content of speech from others

Question 31

What areas are in parietal cortex?

Answer 31

• assoc areas post to primary somatosensory cortex

- unimodal areas: visual asso cortex, auditory assoc areas, somatosensory

Question 32

What happens if damage parietal cortex areas?

Answer 32

agnosias: inability to recognize faces, perceive mvmt (visual agnosias)

Question 33

Where are multimodal areas of parietal cortex?

Answer 33

centered on intraparietal sulcus, monitor relationships of body with outside world

Question 34

Where is the prefrontal cortex? rule?

Answer 34

• frontal lobe ant to primary motor and supplemental motor cortices
• controls activities of other cortical areas; underlies executive functions

Question 35

What is the prefrontal cortex interconnected with?

Answer 35

dorsomedial nucleus of thalamus