Question

Hi. This is a question for my summer neuroscience class.

Q: How many layers are there between the cortical surface and white matter? How do they differ? What are the four major components of the neuron?

Answer 1

How many layers are there between the cortical surface and white matter? How do they differ?

There are six layers dound between cortical surface and white matter.

• Layer 1: Molecualr layer consist of few scattered neurons, including GABAergic neurons. Cajal-Retzius cells, subpial granular layer cells and some spiny stellate cells are found here. Recieves input from M-type thalamus cells.
• Layer II: Granular external layer, with small pyramidal neurons and numerous stellate neurons.
• Layer III: an external pyramidal layer contains small and medium-size pyramidal neuron also non-pyramidal neurons with vertically oriented intracortical axons.
• Layer IV : internal granular layer which has different types of stellate and pyramidal cells. MAain target for thalamocortical afferents from thalamus type C neurons.
• Layer V: internal pyramidal layer has large pyramidal neurons. Axons of this region connect cortex with subcortical structures including the basal ganglia.
• Layer VI : Large pyramidal neurons and many small spindle-like pyramidal and multiform neurons together compose polymorphic or multiform layer.

Four major components of neuron are: dendrites, cell body or soma, axon and axon terminal.

Dendrites: Connects neuron and soma which carries information.

Cell body: Cellular part that contains nucleus.

Axon - Extension of neuron cell body.

Axon terminal - Essential for synaptic contact.