Neurotransmitters

What are Neurotransmitters

Chemical messengers that transmit signals between neurons

Types of Neurotransmitters

• 9 common neurotransmitters

• 40 neuropeptide chemicals (Neuropeptides are short chains of amino acids, acting as chemical messengers in the nervous system)

Neurotransmitter Characteristics

1. Bind to receptor sites on the postsynaptic neuron

2. May be broken down to specific enzymes in the synaptic cleft

3. May undergo reuptake (Reuptake is the reabsorption of a neurotransmitter by a neurotransmitter transporter) (It’s what happens after the job is done)

What are the types of Neurotransmitters

• Small molecules

• Amino acids

• & Others

What are the Small Molecules

• Acetylcholine

• Norepinephrine

• Serotonin

• Dopamine

Acetylcholine (ACh)

• Involved in memory & movement

• Malfunction → Linked to Alzheimer’s disease

Norepinephrine (NE)

• Affects mood, sleep & learning

• Malfunction → Linked to depression

Serotonin

• Involved in mood, appetite & impulsivity

• Malfunction → Linked to depression

Dopamine

• Involved in movement & reward

• Malfunction → Linked to Parkinson’s disease & schizophrenia

What are the Amino Acids:

• Gamma-Amino Butyric Acid (GABA)

• Glutamate

Gamma-Amino Butyric Acid (GABA)

• Acts as a depressant

• Involved inn sleep, movement & anxiety regulation

• Malfunction → Linked to anxiety, Huntington’s disease & epilepsy

Glutamate

• Excitatory neurotransmitter

• Involved in memory & learning

• Malfunction → Can cause damage after a stroke

Other Neurotransmitters:

• Endorphins

• Nitric Oxide

Endorphins

• Act as natural painkillers (analgesic)

• Linked to mood elevation (e.g. runner’s high)

Nitric Oxide

Involved in memory

What are Agonists & Antagonists

Receptor sites can be fooled by other chemicals

What are Agonists

Mimic the action of a neurotransmitter

What do Agonists do

Produce the same effect as the original neurotransmitter

Example of Agonists

Nicotine

What are Antagonists

Oppose the action of a neurotransmitter

What do Antagonists do

Block neurotransmitters by occupying receptor sites

Example of Antagonists

Curare (Stops muscle movement)