Cortical structures

Question 1

Neocortical neurons mostly are ______ cells

Answer 1

Neocortical neurons mostly are pyramidal cells

Question 2

pyramidal cells

Answer 2

Shaped like cone or pyramid, with a long “apical” dendrite out the top, or the apex and goes up vertically to the cortical surface to make synapses.
and several “basal dendrites that comes out the bottom of the cells and spread horizontally
Dendrites spines abound (seat of learning and memory ? )
key feature is long axon that projects to subcortical or there cortical areas.
Principle output neurons of the neocortex
Make excitatory synapses (glutamate)
Bitz cells are the largest pyramidal cells

Question 3

Non pyramidal neurons

Answer 3

smaller neurons , several types (but many are granular/stellate cells)
most have small axons that stay within the cortex
generally inhibitory synapses (GABA)
serves as principe interneurons of the neocortex

Question 4

what are the 6 neocortex layers and describe each one?

Answer 4

1- Molecular layer (few cell bodies, major synaptic later)
2- External granular layer (mostly small granular cells )
3-External pyramidal layer (mostly med/sm pyramidal cells)
4- internal granular layer (outer band of bail larger ; e.g. stria of Gennari in VC)
5- Internal pyramidal layer (inner band of Baillarger , mostly large pyramidal cells)
6- polymorphic layer ( modified pyramidal cells, mostly going to thalamus)

Question 5

More pyramidal cells = less granular cells = ________

More granular cells = less pyramidal cells = ________

Answer 5

More pyramidal cells = less granular cells = a-granular

More granular cells = less pyramidal cells = granular

Question 6

motor has the most ______ axons, so more pyramidal cells [Betz]

Answer 6

motor has the most long axons, so more pyramidal cells [Betz]

Question 7

Called “ _________ “ , in in-between kinds of cortex called “__________” (neither angular nor agranular)

Answer 7

Called “ heterotyprical “ , in in-between kinds of cortex called “homotypical” (neither angular nor agranular

Question 8

Afferent information coming into cortex ends in :

sensory ends mostly in layer _ , From other cortical areas end in layers _ & _, Intralaminar thalamic fivers end in _

Answer 8

Afferent information coming into cortex ends in :
sensory end mostly in layer 4
From other cortical areas end in layer 2 and 3
Intralaminar thalamic fivers end in layer 6

Question 9

Efferent information from form the cortex leaves :

• later III to __________
• layer V to ________ , __________
• layer VI to ________ (feed back return)

Answer 9

Efferent information from form the cortex leaves :

• later III to other cortical areas
• layer V to stratum , brainstem
• layer VI to thalamus (feed back return)

Question 10

In addition to horizontal layers, vertical columns
~__ - __ micrometers wide slab of cortex that responds to a specific stimuli (eg for vision : ___ lines )
Best studied in VC , but evidence suggests this organisation is widespread
Basic building block of neocortex seems to be “___”
~__ micrometers wide, contain ~__ neurons
dozens of minocolumns make up functional models that intersect and interact with other columns
- because cellular architecture seems to link to function, early scientists sought to map the neocortex based on this cellular organisation (horizontal and vertical)

Answer 10

In addition to horizontal layers, vertical columns
~50 - 100 micrometers wide slab of cortex that responds to a specific stimuli (eg for vision : diagonal lines )
Best studied in VC , but evidence suggests this organisation is widespread
Basic building block of neocortex seems to be “minocolumns”
~50 micrometers wide, contain ~100 neurons
dozens of minocolumns make up functional models that intersect and interact with other columns
- because cellular architecture seems to link to function, early scientists sought to map the neocortex based on this cellular organisation (horizontal and vertical)

Question 11

Brodmann areas
Divided neocortex into __ (or __) different cytoarchitectonically distinct areas
He started at central salucs and worked his way around the C

Answer 11

Brodmann areas
Divided neocortex into 44 (or 47) different cytoarchitectonically distinct areas
He started at central salucs and worked his way around the C

Question 12

what are the types of neocortical areas and what do they serve ?

Answer 12

Primary (Sensory and Motor)
Unimodal Association (Sensory and Motor) Heteromodal Association (higher-order cognition)
Limbic (emotion , memory m learning)

Question 13

What does these properties refer to ? (what type of neocortical area ?

M1, S1, V1, A1, etc
Regions most associated with outside world
Topographically organised (exaggerating more important features ; homunculus )

Answer 13

Primary (Sensory and Motor)

Question 14

What does these properties refer to ? (what type of neocortical area ?
premotor, BA 18, 19 , …
elaborate on the info from primary cortex

Answer 14

Unimodal Association (Sensory and Motor)

Question 15

What does these properties refer to ? (what type of neocortical area ?

PFC , infereiot
participate in various stimulus response if processing is needed

Answer 15

Heteromodal Association (higher-order cognition)

Question 16

Primary cortex (auditory, visual , motor , somatosensory) has \_\_\_\_\_\_\_\_\_\_
Heteromodal Association cortex has \_\_\_\_\_\_\_

Answer 16

Primary cortex (auditory, visual , motor , somatosensory) has shrunk esp olfactory
Heteromodal Association cortex has expanded (dark blue / purple )

Question 17

Unimodal cortex by lobe:
Frontal : \_\_ 
Parietal : \_\_ 
Occipital : \_\_
Tempotal : \_\_

Answer 17

• Frontal: premotor , frontal eye fields, supplementary motor
• Parietal: superior parietal lobule (somatosensory association BA 5, 7 , parietal eye field
• Occipital: BA 18 and 19 ,Basically the entire lobe expect calcarine
• Tempotal: superior temporal gyrus auditory association (BA 42, 22)

Question 18

Heteromodal Association Cortex:

Most of what’s left (that ’s not limbic )
_____

Answer 18

Inferior parietal lobule
precuneus
Fusiform
Inferior temporal 
PFC : parts of orbital frontal , DFPFC , parts of superior, middle , inferior frontal gyrus

Question 19

White matter tracts

______ (superior-inferior) eg ____
______ (interhemisphericl ; lateral-medial ) eg ____
______ (intrahemisphericl anterior-posterior) Many! ( e.g. ____ )

Answer 19

White matter tracts

Projection (superior-inferior)
eg Corticospinal tract Corona radiata , Internal Capsule, Auditory and optic radiations
Commussural (interhemisphericl ; lateral-medial ) eg Corpus callusom , anternoir commusure , Hippocampus
Association (intrahemisphericl anterior-posterior)
Many! ( e.g. superior longtitunal fasculus, inferior longtudinal fasculus , Arcuate fasciclus, Cingulum, Fornix, Uncinate fascculus)