Neurophysiology Week 2; Neurotransmitters

Which of the following is NOT a requirement for a chemical to be a neurotransmitter?

• It must have the same effect, when artificially applied to a membrane, as when released by a neuron.

• Must be inactivated after being released.

• Must be produced by, or found in, a neuron

• Must act on a presynaptic receptor and cause a biological effect

Answer explanation

Must act on a Postsynaptic receptor and cause a biological effect

Where are neurotransmitter gasses synthesized?

• Axon terminals

• Soma (cell body)

Answer explanation

Gases cannot be stored and are synthesized in the axon terminals

This neurotransmitter is the "feel good" reward chemical in the brain. It controls movement, emotional response, and pleasure/pain.

• CO

• Dopamine

• Serotonin

• Acetylcholine

Answer explanation

Dopamine is the feel good reward chemical in the brain.

Controls movement, emotional response, pleasure/pain, balance and controlled movements.

Synthesis is from Tyrosine. (Dopamine->Norepinephrine->Epinephrine)

This neurotransmitter can be excitotoxic and is possibly linked to glaucoma-

• Histamine

• GABA

• Glycine

• Glutamate

Answer explanation

Glutamate is common in sensory pathways (Retinal photoreceptors!)

Principal excitatory neurotransmitter in CNS

Excessive activation of glutamate receptors- Epilepsy, Excitotoxic neurodegeneration, paralysis

~possible Glutamate excitotoxicity in glaucoma

By what mechanism does Botulinum Toxin affect the action of Ach?

• Prevents release

• Prevents Re-uptake

• Prevents Synthesis

• Prevents receptor binding

Answer explanation

The toxin cleaves the SARE proteins that facilitate the release of Ach.