Cytology-Cortex Flashcards
What are the areas indicated below?
These are all the associated areas mediating cognitive function: 1) Parieto-Occipito-Temporal 2) Orbitofrontal 3) Prefrontal and 4) Limbic areas
What are the two main cell types that compose the cerebral cortex?
Pyramidal cells (excitatory output neurons) and stellate/granule cells (sensory input neurons).
How many layers is the cerebral cortex composed of? What is their function?
1) Ascending axons 2) Sensory from other cortical layers 3) Output to other cortical layers across corpus callosum 4) Sensory stellate cells that receive thalamic input 5) Output to brainstem and spinal cord 6) Output to thalamus
What is the functional unit of organization in the cerebral cortex?
Cortical columns. The cells within each column are very tightly linked with one another and have roughly the same function.
What is the most famous manifestation of cortical columns?
Ocular dominance columns in the visual cortex. Each eye activates one cortical column.
How is sensory image usually transferred from one hemisphere to another?
Corpus callosum shares information received in one hemisphere with the other hemisphere. For example, if someone with a lesion in the corpus callosum stared at this image and was asked to respond verbally (using the left brain), they would only see the man in the right image.
How can you lesion the corpus callosum?
Agenesis of CC, vascular accidents, myelin disorders and epilepsy treatment.
What happens if you have a lesion in the anterior part of the corpus callosum? In the posterior part?
Anterior: impaired coordination between premotor and motor areas that makes learning bilateral motor tasks difficult. Posterior: inability to transfer verbal and motor commands that involve interacting with the environment
Where does the fetal neocortex first develop?
The neuroepithelium gives rise to the preplate (composed of marginal zone and subplate) in the wall surrounding the neural tube (ventricular zone)
Which cortical layers seen below arrived at their location first during gestation?
Layer 1 = marginal zone, arrived first. Then layer 6, then 5, then 4, then 3, then 2.
What region of the developing cortex is responsible for organizing the developing neurons and axons?
Subplate.
How do the excitatory neurons get from the ventricular zone to their place in the cortex during gestation?
They migrate along the radial glial cells. Note that once they are finished as a “scaffold” they become astrocytes.
What cells are the neural progenitor cells in the developing cortex?
Radial glial cells, they split and become new cells during development (neurons early on, glial cells later on in development)
Where are two major sources of neural progenitor cells?
Subventricular zone and the ventricular zone
What cells do not initially use the radial glia to migrate radially in the cortex?
The inhibitory neurons initially migrate laterally in the ganglionic eminence before migrating radially up the radial glial cells.
