Neurons

What's a neuron for?

A neuron is a nerve cell that is the basic building block of the nervous system and is specialised to transmit information throughout the body.

Structure of the Neuron

• Cell Body
• Axon
• Dendrites
• Myelin Sheath
• Synapse

Functions

Cell body

• Factory of the neuron
• Produces all the proteins for the dendrites, axons and synaptic terminals

Axon

• Main conducting unit of the neuron, capable of conveying electrical signals along distances

Dendrite

• Branch out in treelike fashion and serve as the main apparatus for receiving signals from other nerve cells.
• They function as an "antennae" of the neuron and are covered by thousands of synapses.

Myelin Sheath

• Wraps around certain nerve axons, serving as an electrical insulator that speeds nerve impulses to muscles and other effectors.

Synapse

• Structure that permits a neuron to pass an electrical or chemical signal to another cell

The dendrites of neurons receive information from sensory receptors or other neurons. This information is then passed down to the cell body and on to the axon. Once the information as arrived at the axon, it travels down the length of the axon in the form of an electrical signal known as an action potential.

Neurotransmitters

Chemical messenger that carries, boosts and modulates signals between neurons

Serotonin

Responsible for maintaining mood balance, and a deficit of serotonin is linked with depression.

Serotonin is responsible for

• Mood and social behavior
• Appetite and digestion
• Sleep
• Memory
• Sexual desire and function.

Dopamine

Neurotransmitter that helps control the brain's reward and pleasure centers.

Dopamine deficiency results in Parkinson's Disease, and people with low dopamine activity may be more prone to addiction.

Someone who uses amphetamines over time gets an initial “high” or pleasure from the short-term increase in dopamine.

Over time, the amount of dopamine becomes depleted, leading the user to require higher doses to experience the same pleasurable effect.