What is an endothelial cell?
Endothelial cells line every blood vessel in the body
Where are Purkinje cells found?
In the cerebellar cortex
What is the average distance of the synaptic cleft?
What is the average diameter of a human axon?
What is the cresyl violet Nissl stain used to distinguish, and how is this done?
The cresyl violet Nissl stain is used to distinguish neurons from other types of cells in the brain (glia and Endothelial cells). This is possible due to the high density of rough endoplasmic reticulum (rER) found in neurons; called Nissl bodies.
Explain how myelin stains are used
By staining the oligodendracyte endfeet, be underlying neuronal axons and tracts can be studied.
What does the Golgi Silver stain reveal?
The golgi silver stain reveals the full morphology of neurons including dendritic trees and axons
Name three applications of immunohistochemistry and describe how it works.
Immunohistochemistry is used to distinguish neuron from glia, differentiate the different glial cell types (astrocytes, oligodendrocytes and microglia), and to distinguish neuronal categories.
Immunohistochemistry works by selecting for particular antigens (proteins), by exploiting the principle that antibodies bond specifically to antigens (proteins).
The Morphological classification of neurons is based upon which two factors?
Their external appearance and there topography (location)
Where is endoplasmic reticulum found in neurons?
In the cell body and dendrites, but not the axon.
How does the Nessus stain stain neurons and glial & endothelial cells differently?
The Nissl stain shows the nucleus and Soma of neurons but only the nucleus of glial and endothelial cells.
Which molecular structures are detected in the nucleus and nucleolus and the ribosomes of the rER using the Nissl stain?
DNA and RNA in the nucleus and nucleolus, and RNA in the ribosomes of the rER
What for the nucleus basalis in the base of the brain?
A cluster of neurons
Name the five cytoarchitectural differences in the lamina
- The size and density of neurons
- The thickness of the layers
- Neuronal morphology
- Layers of neurons may be separated by layers which are richer in glial cells and myelinated neuronal processes
- Connectivity input and output it to each layer differs
What is found in the borders separating the six laminae of the cerebral cortex?
These borders are a relatively neuron free, they contain glia and neuronal axons.
What is found underneath the six layers of cerebral cortex laminae?
Subcortical white matter
Although they have distinct inputs and outputs, which two layers of the laminae are difficult to distinguish from each other?
Layers two and three. They contain medium sized, mainly pyramid or neurons.
Which layer of the laminae contains an input layer from the thalamus, and is thick in sensory cortices?
Which layer of the laminae contains some of the largest (generally) pyramidal neurons in the brain, such as in the primary motor cortex (Betz cells)?
Which layer of the laminae contains medium size neurons?
Which layer of the laminae is very thin, without neuronal cell bodies? It contains myelinated neuronal processes (apical dendrites of pyramidal neurons and horizontally oriented axons), and has a high density of astrocytes?
Explain what is fortuitous about the golgi Silver stain only labelling a few of all the neurons present in the CNS tissue
This allows us to get a more detailed view of those neurons that are stained, showing the full dendritic tree, soma shape, dendritic spines and axon. If too many neurons were stained we would not be able to make up this detail.
How many times is a myelin sheath capable of encircling an axon?
More than 200 times