Lectures 55-56: Cortex Flashcards
Ocular dominance columns are divided by…what layer?
Divided by eye; Layer 4C
What is the other type of radial column?
Orientation columns
Integration of color information occur by…these areas are called?
Projections superficially and deep to 4C; Colorful blobs
What are areas of achromatic regions called?
Interblobs!
Streams and fasciculi from visual cortex and information carried (2)
Dorsal stream/superior longitudinal fasciculus (where) and ventral stream/inferior longitudinal fasciculus (what)
Where pathway answers what question? Where does it project?
Where an item is located in space; parietal/frontal lobes
What eye movement is impacted by the dorsal stream?
Visually-guided control of saccades
Dominant (L) parietal lobe…
Mediates attention to contralateral (R) hemi-space
Non-dominant (R) parietal lobe…
Mediates attention to bilateral hemi-space
So, if you damage the non-dominant parietal (R) lobe, you can get…Why?
(L) Hemi-neglect; because the left hemi-space ONLY FF
What pathway answers what question? Where does it project?
Identifies objects; temporal lobe
Fusiform gyrus does what?
Recognizes faces
Visual agnosia
Inability to visually recognize an object
Action selection means…what brain region.
Which behaviors will be expressed and which won’t be, what is the plan?; DL/VLPFC
Suppression of action brain region
Orbital frontal cortex
Action itself brain region. This region has what subdivisions?
Medial PFC; cognitive and affective subdivions
What is the cingulum and what does it do?
Fiber bundle; learns to correct mistakes, reinforces behaviors that reduce pain
Describe the cingulum pain pathway…
Pain information is mapped onto cingulate gyrus, transmitted via cingulum to various places (i.e. temporal lobe: hippocmapus)
Hippocampal formation projects where via what
Mammillay bodies, septal nuclei, ventral striatum; fornix
Mammillary bodies project…
To the thalamus
The cingulum also sends a projection to this structure to mediate what pain-related emotion?
Amygdala; fear
Describe the mesocortical pathway projections and what it is responsible for?
VTA to DLPFC, VMPFC, cingulate, olfactory bulbs; cognition/motivation/emotional responses pathway
Layers: Archicortex and example
3 (hippocampus)
Layers: Paleocortex
3-5 (transitional cortex)
Layers: Neocortex
6 (mammals only)
Where do we find pyramidal cells in neocortex?
All layers, but mainly 3 and 5
What are the smaller cells of the neocortex? What layers?
Granular cells; all layers, but mainly 2 and 4
Name the layers
1 Molecular, 2 outer granular, 3 outer pyramidal, 4 inner granular, 5 inner pyramidal, 6 polymorphic
Dendritic spines receive what kind of input? Whats an important projection to neocortex via these spine interactions?
Excitatoy (glutamatergic); thalamocortical interactions
Where is the UMN deficit in ALS? AD?
Large pyramidal cells of Layer V (i.e. motor deficits); Widespread loss of pyramidal cells (cognitive dysfunction)
Non-pyramidal cells use what NT. What’s an associated disease?
GABA; epilepsy
Homotypical cortex
Equal sized layers of cortex (association)
Sensory cortex: cell type and other name
Predominance of granular cells; Koniocotex
Motor cortex: cell type and other name
Predominance of pyramidal cells; Agranular cortex
Differences in cortical thickness depends on…
Its function! Example: Layer III of Association > Layer III of Occipital (less pyramidal cells)
If a cortical region has more pyramidal cells it’s going to be thicker/less thick
Thicker
Inputs to neocortex (4)
Neocortex, allocortex, thalamus, other subcortical nuclei (brainstem, etc)
Intrinsic (cortical) inputs to these layers
I, II, III
Extrinsic inputs to these layers
III, IV
As an example, the LGN projects to which layer (broadly)?
IV
Layer IV projects where…then where…then where…
III; V; outputs to association areas
What are the short arcuate bundles? Also called?
WM connecting close regions of cortex; U fibers
Uncinate fasiculus connects
Interconnects anterior frontal lobe (OFC) with anterior temporal lobe (hippocampus, amygdala)
Superior longitudinal fasiculus connects; what does the arcuate fasiculus connect?
Frontal, partietal, and occipital lobe; Wernicke’s and Broca’s territory
Inferior longitudinal fasiculus
Occipital and temporal lobe
Cingulum is located…
Internally within the cingulate gyrus
Forceps major interconnects…Function?
Occipital poles; joins visual fields
Forceps minor interconnects…
Frontal lobes
Anterior commissure interconnects…
Temporal lobes and amygdala
What are projections from the ACh and monoamine nuclei like?
They blanket the cortex, not precise like other inputs
Horizontal: Plexus of Exner connects and layer
Cortex regions to one another; Layer I (cortico-cortico connections tend to be superficial)
Horizontal: Kaes-Bechterew connects and layer
Mediates inputs from thalamus that are not from specific sensory relay nuclei; Layer III
Horizontal: Outer stripes of Baillarger
Carries specific thalamic nuclei radiations; Layer IV
Horizontal: Inner stripes of Baillarger
Carries outputs; Layer V
Outputs from neocortex (5)
- Cortex (neo and allo), 2. Thalamic, 3. Basal ganglia, 4. Brainstem structures nuclei, 5. Spinal cord
Layers III and superficial IV project to…
Cortex
Layer V projects to…
Non-thalamic, subcortical areas
Superficial VI projects to…
Thalamic sensory relay nuclei
Deep VI projects to…
Non-specific thalamic
Cortex is organized vertically into…scaffolding?
Radial columns; pyramidal cells
