Chapter 6 - Neurotransmitter systems

Question 1

What criteria do neurotransmitters have?

Answer 1

1. The molecule must be synthesized and stored in the presynaptic neuron.
2. The molecule must be released by the presynaptic axon terminal upon stimulation.
3. The molecule, when experimentally applied, must produce a response in the postsynaptic cell that mimics the response produced by the release of neurotransmitter from the presynaptic neuron.

Question 2

What are the two methods of neurotransmitter localization mentioned in the book?

Answer 2

Immunocytochemistry and in situ hybridization.

Immunocytochemistry is done by injecting the neurotransmitter into an animal. Often bound to a larger molecule. The neurotransmitter colors the areas in which the neurotransmitter binds.

In situ hybridization is an mRNA probe is applied to to a section of brain tissue. The probe is made radioactive so that it will develop a film that is sensitive to radioactivity. The probe will stick to a particular peptide located in the neuron.

Question 3

What is microionophresis?

Answer 3

A tiny glass pipette containing an ionized solution is positioned next to the postsynaptic membrane of the neuron.

Question 4

What is a ligand?

Answer 4

A chemical compound that binds to a specific site on a receptor.

Question 5

What neurotransmitter is synthesized in all motor neurons in the spinal cord and brain stem?

Answer 5

Acetylcholine (ACh)

Question 6

What is the benefit of the complicated second messenger system?

Answer 6

It allows for signal amplification as each step releases more energy.

Question 7

What is the most commone excitatory neurotransmitter in the brain?

Answer 7

Glutamate

Question 8

what is the most pervasive inhibitory neurotransmitter?

Answer 8

GABA