L2 Cells Of The Nervous System Flashcards
What are Glia and their main purpose?
They are supporting cells like ‘glue’
They maintain homeostasis, protection, assist neural function
What is the estimated number of neurons and glia?
85 billion of each cell type
What does Nissl (Franz) staining do?
- Allow us to distinguish between neurons and glia
- Allows visualisation of variation in size, density and distribution.
What is the soma?
The soma, also known as the cell body, is the central part of a neuron. It’s the neuron’s control center, containing the nucleus and various organelles essential for the cell’s function and maintenance
What are the four major components of the neuron?
- Cell body, soma, perikaryon.
* Neurites: - Dendrites.
- Axons
- Presynaptic terminal.
Name me 2 neurites (projections)
Dendrites
Axons
Why does a neuron have a high density of mitochondria?
Neurons do a lot of active transport therefore it needs lots of ATP
What does silver chromate do in Golgi staining?
Stains all the parts of a neuron
What are MAPs and give example?
Microtubule associated proteins, eg: tau.
Describe the structure of the axon
- Axon hillock (region where axon originates from cell body (soma))
- Axon initial segment ( unmyelinated portion of the axon immediately following axon hillock)
- Axon collaterals (a side a branch that extends from the main axon to distribute its signal)
- Axon terminal or terminal bouton branched endings to the axon that connects to other neurons)
Describe the dimensions of the axon
- No rough ER or fewer free ribosomes
- Membrane composition different
- 1mm < X > 1m in length
- 1um - 25um diameter
What is immumohistochemistry (IHC)?
Technique used to visualise and analyse the distribution and localisation of specific proteins (antigens) within cells and tissues
What does an axon with many collaterals mean?
It has multiple side branches which means it has high levels of divergence
How does IHC work?
A secondary antibody, conjugated with an enzyme or a fluorescent dye, is applied. This antibody binds to the primary target
Primary antibody specifically binds to the target antigen
What is axoplasmic transport?
Axoplasmic transport, also known as atonal transport, is a vital cellular process responsible for the movement of materials within a neuron, specifically along its axon
What happens in the synaptic cleft?
Releasing of neurotransmitters occur here.
How was slow axoplasmic transport discovered?
Discovered by tying a knot. Discovered by forming a knot which led to a bulge there which must indicate some sort of build up of transported materials
What is the difference between anterograde and retrograde transport?
Both types of axonal transport.
- Anterograde = Movement away from the cell body (soma) and towards axon terminal. Motor protein - kinesin
- Retrograde = Movement towards cell body (soma) from the axon terminal. Motor protein dynein
What does kinesin do?
It’s a motor protein that ‘walks’ along the microtubules, carrying the cargo towards the synapse
What does HRP do?
Horseradish peroxidase is injected to trace neuronal connections and pathways
What do dendrite branches form when together?
Dendritic trees (Dendritic arbors)
What is retrograde transport?
It’s a cellular process that involves the movement of materials from the axon terminal of a neuron back towards its cell body (soma)
Transported by dynein
What is the structure to function relationship of dendrites?
Convergence since it is the primary site where a neuron receives input from many other neurons
Why do dendrites have thousands of synapses?
The thousands of synapses on a dendrite are crucial for the neuron’s ability to receive, process, and respond to information, making it a fundamental building block of brain function.
