Introduction to cerebral cortex Flashcards
What is the name of the fissure that divides the cerebral cortex into left and right hemisphere?
Longitudinal fissure
What are gyri and sulci?
Gyri -ridge; Sulci - depression
What does Nissl staining of the cortex reveal?
Difference in lamination patterns. Nissl substance: ribosome clustering, including the position of cell bodies.
How many layers are there for isocortex(neocortex)?
6
How many layers are there for allocortex? Which two parts are included?
- Paleocortex (olfactory cortex) and archicortex (hippocampus)
Layer I
molecular layer, not much cell body, stain light. Lots of axons and dentrites. Lots of synaptic activities.
Layer II, III
external granular layers, and external pyramindal layer
Which layers are included in the supragranular layer?
Layers I,II, III.
What is the other layer of Layer IV?
(Internal) granular layer
What is special about Layer IV?
Special type of cell (name), lots of thalamic input, primary sensory information
What is included in the infragranular layer?
Layers V (internal pyraminal layer) + VI (fusiform layer)
What are the cells in the neocortex?
Glia, astrocytes, oligodendrocytes, microglia. As for neurons - spiny stellate cells, pyramidal cells (main excitory cells) onpyramidal cells (GABA neurons)
What are the characteristics of spiny stellate cells?
Only in layer 4, shape like star, dentrites have spines, axons much thinner than dentrites, projecting information vertically to layer2/3 (more than to the deeper layer); excitatory neurons: use glutamates as a transmitter. First stop for the external information coming to cortex
What are about pyramidal neurons
Most abundant in cortex, found esp in 1, 2/3, 5 layers. has two dense dentritic areas, one near the somite (basal dentrites+oblique dentrites), one near the layer i (apical dendrite, ending in apical tuft). Relative output is downward (axon direction).
Tell me about neurons being “spiny”?
The pyramidal neuron, providing excitatory inputs occur on dendritic spines. Excitatory neurons use glutamate as the NT. Each one typically receives single excitatory input. Constantly changing, remodeling
Which layer of neurons providing primary output neurons
Layer 5 pyramidal neurons.
What is the major type of neurons in Layer 6?
Thalamic projecting neurons Having basal dentrites, and apical dentrites. The tuft is in layer 4 where it receives input (with the spiny stellate input, thalamic)
What is excitotoxicity?
Too mch excitation input to the neuron
How might you protect against excitotoxicity?
block excitation, enhance inhibition, and limit action potential
Describe the cortical circuit with some inhibitory neurons
- Thalamic input to layer IV SS cells. 2. SS project to P cells in layer II/III. 3. P cells are highly interconnected and synpase with layer V. 4. Layer V, VI P cells provide the majority of cortical output. 5. Feedforward and feedback inhibition flow of excitatory activity.
How does the cortex work?
Compare expectation with reality. Pyramidal neurons integrate top-down (predictive) and bottom-up (perceptive) information.
what is the structure of the cerebral cortex called?
columnar, which represents the functional unit of cerebral cortex
Is the sensory cortex the pre- or post-central gyrus
Post-
What are the structures that connect the right and left hemisphere of the brain?
Corpus callosum and anterior commissure
