Neurons

Question 1

What is a typical neuron composed of?

Answer 1

Soma (cell body)​
Dendrites ​
Axon​ ​

Question 2

What is the role of the axon?

Answer 2

Axons are responsible for relaying / sending information from one neuron to the next.

Question 3

What is the role of the synapse?

Answer 3

Point of communication between neurons​.

Occurs by synaptic transmission​.

Axon is referred to as the presynaptic location of the neuron​.

Electrical-to-chemical-to-electrical transformation​.

Synaptic transmission dysfunction in mental disorders​.

Question 4

What is the role of the dendrites?

Answer 4

Dendrites are responsible for receiving and processing information sent from the axon of other neurons.

Question 5

What are glial cells?

Answer 5

Essential for the support and nutrition of the neurons.

Provide structural support​.

Form the scaffolding of the brain​.

Unable to produce Action Potential​.

PNS and CNS glia​.

Microglia become activated following injury, inflammation, immune insults​.

Gain macrophage-like status​.
Become phagocytic​.

Question 6

What is the link between astrocytes and the Blood-Brain Barrier (BBB)?

Answer 6

Peripheral blood vessels are ‘leaky’​.

CNS blood vessels are ‘tight’ - the BBB.

Endothelial cells connected by tight junctions and surrounded by astrocyte processes.​

Astrocyte activity has been linked to maintenance and regulation of BBB.

Protects brain from harmful substances in blood​.

Most drugs cannot cross the BBB​.

However, researchers have discovered various ways to overcome this by high jacking transport mechanism across the BBB.

Question 7

Why do astrocytes take up glutamate at synapses​?

Answer 7

Glutamate main excitatory neurotransmitter in brain​.

Astrocytes take up glutamate and recycle it​.

High level of glutamate causes excitotoxicity – destruction of neurons.​

The most common cause is ischemia during stroke.

Lack of oxygen causes glutamate transporters to fail and glutamate accumulates.​

Question 8

Why do astrocytes take up potassium released by neurons​?

Answer 8

Potassium (K+) is released from neurones during action potentials​.

Astrocytes take up this K+ and stop it building up​.

High K+ causes asynchronous neuronal activity​.

Leads to epilepsy.

Question 9

What are the 3 different types of glial cells?

Answer 9

• Astrocytes (star cells)
• oligodendrocytes
• microglial cells

Question 10

How do neurons communicate?

Answer 10

Neuronal communication relies on the ability of neurons to provide maintain an electrical gradient that allows them to produce electrical signals