Unit 5 Phys Nervous Tissue, Part O Classification of Neurotransmitters, Receptors, and an Overview of G Protein Receptors

Glutamate

Type of neurotransmitter found in the brain and spinal cord that is always excitatory

Glycine

The two types of neurotransmitters found in the brain and spinal cord that are always inhibitory are ___________________________ and GABA

GABA

The two types of neurotransmitters found in the brain and spinal cord that are always inhibitory are ___________________________ and glycine

True

True of False: Excitatory neurotransmitters cause depolarization by EPSPs and promote action potential generation.

False

True of False: Inhibitory neurotransmitters cause depolarization by IPSPs and inhibit action potential generation.

Nicotinic receptors

Name the type of acetylcholine (ACh) receptors that is stimulated by both acetylcholine and nicotine.

Muscarinic receptors

Name the type of acetylcholine (ACh) receptors that is stimulated by both acetylcholine and muscarine

Curare

Name a substance discussed in class that will inhibit nicotinic receptors

Atropine

Name a substance discussed in class that will inhibit muscarinic receptors

G protein coupled receptors

Are a group of transmembrane protein receptors that cross the phospholipid bilayer seven times. They bind with a ligand outside the cell and activate signal transduction pathways inside the cell and, ultimately, cellular responses.

Gamma

G protein complex is attached to the ligand gated receptor and consists of 3 subunits designated alpha, beta, and _______

First messenger

Term of the signal molecule that binds to the GPCR and causes a conformational (shape) change in the receptor and activates it.

True

True or False: In the inactive form, the alpha (α) portion of the G protein is bond to guanosine diphosphate (GDP) which is where G proteins get their name because they bind to guanosine nucleotides.

True

True of False: When activated by the GPCR the bound GDP is exchanged for guanosine triphosphate (GTP). This allows the G protein to dissociate from the receptor and split into two activated subunitsrue

Adenylate cyclase

A G protein subunit can activate a membrane enzyme known as ______________________, which will catalyze the formation of many intracellular cAMP (cyclic adenosine monophosphate) molecules that will continue to carry the signal and act as second messengers.

Protein kinase A

One of the actions of cAMP is to bind to and activate an enzyme called __________________ . Protein kinase A phosphorylates (addition of phosphate groups) of other enzymes or target proteins.

False

True or False: Protein kinase A breaks down phosphatases by the addition of oxygen atoms. This oxygenation acts as a "molecular switch" turning the protein either on or off.

Muscarinic receptors

Name the type of GPCR found in the heart and functions to slow heart rate.

Acetylcholine

The vagus nerve synapses with cardiac pacemaker cells and release what neurotransmitter that will bind to muscarinic receptors and slow down the heart?

K+/ K+

When muscarinic receptors on pacemaker cells of the heart get activated the G-protein dissociates and activates _______ channels to open leading to the diffusion of _________ ions out of the cardiac cell. Answer will be in the form of ____/______

False

True or False: When muscarinic receptors on pacemaker cells get activated the cell becomes hyperpolarized, producing an excitatory postsynaptic potential (EPSP) and the heart rate slows.

True

True or False: Monoamines: Group of regulatory molecules that include epinephrine, norepinephrine, dopamine, and serotonin

Monoamine oxidase Inhibitors

Name the substance that can block monoamine oxidase, the enzyme that breaks down monoamines and can be used in treatment of depression because they keep the amount of monoamines in the synapse high and thus promote their effectiveness. Hint: Goes by the abbreviation MAOIs or MAO inhibitors

Serotonin

Antidepressant drugs such as Prozac, Paxil, and Zoloft block the reuptake of __________________ into the presynaptic endings and thereby increase the neurotransmitter's effectiveness by keeping it in the synapse longer

Caffeine

Name the drug we discussed in class whose principal mode of action to block (antagonist) adenosine receptors in the brain's arousal system.

Adenosine receptors

Caffeine is a drug whose principal mode of action to block (antagonist) what kind of receptors in the brain's arousal system.

Serotonin

In the treatment of depression, SSRIs are a class of medications that are used to treat depression by blocking the reuptake of which neurotransmitter into the presynaptic axon terminals.