Neurotransmitters

Question 1

What is the definition of cellular metabolism

Answer 1

It refers to chemical reactions within cells

Question 2

What molecules do metabotropic receptors use as energy used to catalyze chemical reactions

Answer 2

these proteins use GTP molecules instead of ATP molecules

Question 3

1. When are G proteins “ON”/activated? what can they do in this state?
2. When are they “OFF”/inactivated?

Answer 3

1. G proteins are ON when they’re bound to GTP - in this state, they can catalyze chemical reactions (lasts 10 seconds to a few minutes)
2. The G protein become OFF when the GTP molecule turns into GDP

Question 4

How are g protein-gated ion channels opened?

Answer 4

A signaling molecule has to activate a metabotropic receptor, allowing a g-protein to become activated. This activated g protein can then bind to a g-protein-gated ion channel

Question 5

True or false: If only neurotransmitters (like glutamate) is ever released onto a synapse, it will only contain ionotropic receptors

Answer 5

FALSE - most synapses contain both ionotropic and metabotropic receptors

Question 6

Name 4 types of places where a synapse can form

Answer 6

On smooth dendrite (dendritic shaft), on a dendritic spine, on a somatic membrane or on an axon terminal (axoaxonic synapse)

Question 7

What effect would an axoaxonic synapse cause by hyperpolarizing the axon terminal of a downstream neuron? (presynaptic inhibition)

Answer 7

The voltage-gated calcium channels would not open as much as they normally do when there’s an action potential. This would reduce neurotransmitter release from the downstream neuron when it has an action potential

Question 8

What effect would an axoaxonic synapse cause by depolarizing the axon terminal of a downstream neuron?

Answer 8

Its voltage-gated ion channels are more likely to open when an action potential arrives: this would increase neurotransmitter release from the downstream neuron when it has an action potential

Question 9

What’s the role of an autoreceptor?

Answer 9

They’re located on a presynaptic membrane& they make the cell sensitive to its own neurotransmitter release

Question 10

1. What are auto receptors gated by?
2. Are autoreceptors always ionotropic or metabotropic; are they always inhibitory or excitatory?

Answer 10

1. They’re gated by the release of neurotransmitters from the cell they’re in
2. Autoreceptors are always metabotropic and inhibitory

Question 11

What is the main inhibitory neurotransmitter? Why?

Answer 11

GABA, because gaba receptors let chloride in

Question 12

What is the main excitatory classical neurotransmitter? Why?

Answer 12

Glutamate, because all ionotropic glutamate receptors let sodium in

Question 13

1. What are neuromodulators
2. Name a few example

Answer 13

1. They’re neurotransmitters that act on metabotropic receptors & tend to exert modulatory influence on cell activity
2. Dopamine, norepinephrine, acetylcholine, serotonin

Question 14

Signaling molecules in the blood are called

Answer 14

hormones

Question 15

What type of neurotransmitters are
1. Endocannabinoids
2. Nitric oxide

Answer 15

1. Endocannabinoids - lipid-based neurotransmitters
2. Nitric oxide - gastrotransmitters

Question 16

1. What effects do drugs that activate glutamate receptors have
2. What effects do drugs that block glutamate receptors have

Answer 16

1. Activate - cause seizures & excitotoxicity
2. Block - slow you down

Question 17

What’s the difference between noradrenaline/norepinephrine and adrenaline/epinephrine

Answer 17

Noradrenaline - used as neurotransmitter in CNS
Adrenaline/epinephrine - hormone in da body

Question 18

Where are conventional neurotransmitters
synthesized and packaged

Answer 18

Synthesized - locally in axon terminals
Packaged - small synaptic vesicles that dock close to the site of Ca2+ entry in the axon terminal

Question 19

Where are neuropeptides synthesized and packaged

Answer 19

Synthesized in the cell body, then transported down the axon and released just once

Packaged in large dense core vesicles that dock a ways back from the site of Ca2+entry in the axon terminal

Question 20

What happens to these after they leave the neuron (are they recycled, do they go elsewhere, etc)
1. Conventional neurotransmitters
2. Neuropeptides
3. Lipid-based signaling molecules

Answer 20

1. Conventional neurotransmitters - get recycled & reused
2. Neuropeptides - not recycled (may diffuse long distance)

Question 20

What packages monoamines (seretonin, norepinephrine & dopamine)

Answer 20

The vesicular monoamine transporter

Question 21

What neurotransmitters are catecholamines

Answer 21

Dopamine and norepinephrine