Presynaptic Nt transmission

Question 1

3 types of NT

Answer 1

1. amino acids
2. amines
3. peptides

Question 2

steps to protein

Answer 2

amino acid - peptide - poly peptide - protein

Question 3

criteria for classifying NTs

Answer 3

1. synthesis and localization
2. release
3. response mimicry
4. inactivation

Question 4

Synthesis

Answer 4

the candidate NT and its enzyme must be shown to be contained in the same neuron or axon terminal

Question 5

methods of synthesis/localization

Answer 5

1. immunocytochemistry
2. in situ hybridization

Question 6

immunocytochemistry

Answer 6

Using labelled antibodies to anatomically localize NTs or enzymes that make it

Question 7

steps of immunocytochemistry

Answer 7

• Nt candidate is injected into animal
• antibody should attach to candidate
• antibody is taken out and dyed
• inject it back into the cells and it so they will color the cells that cntaint that NT

Question 8

In situ hybridization

Answer 8

• tagging a strand of complementary mRNA which synthesizes a molecule

Question 9

steps of in situ hybridization

Answer 9

• build synthetically a a complementary mRNA strand to the one of interest
• color that mRNA
• see if where it attaches to the mRNA that synthesizes the enzyme of interest

Question 10

release

Answer 10

NTs released by the presynaptic neuron must be released once activated

Question 11

How to show release

Answer 11

• taking a smaple of fluid that bathes the neurons and testing whether it mimics the activity of the intact synapses

Question 12

optogenetics

Answer 12

using light to stimulate one specific type of Nt in the brain at a time

Question 13

response mimicry

Answer 13

in experiments, the candidate must produce a response that is the same of the response of the post synaptic neuron to that NT

Question 14

methods for release

Answer 14

optogentics

Question 15

Iontophresis

Answer 15

• Nt candidate is dissolved in a solution that gives it a net charge. then is slowly released from a pipette next to the presynaptic membrane of a neuron to see if iy has the same effects as the NT

Question 16

Inactivation

Answer 16

• molecule needs to be actively removed from synaptic cleft
• degradation or reuptake

Question 17

Peptide synthesis

Answer 17

peptides are synthesized in the soma of the neuron and transported by the secretory granules to the axon terminal

Question 18

synthesis of amines and amino acids

Answer 18

they are synthesized from precursor molecules in the cytosol and stored in vesicles in the axon terminal
- precursors are modifified by by enzymes

Question 19

dale’s principle

Answer 19

one Nt is made in one cell
- false, there could be different NTs in one cell

Question 20

Rate limiting steps

Answer 20

-a controllling step allows for the overall control of Nt synthesis
- to regulate

Question 21

Amine NT

Answer 21

• acetylcholine
• catecholamines
• serotonin

Question 22

synthesis of acetycholine

Answer 22

• the enzyme ChAt is made in the soma and then syntheiszes ACh in the terminal from choline (precursor) and acetyl
• then degraded back into acetic acid and choline by AChe

Question 23

catecholines

Answer 23

• dopamine
• norepinephrine
• epinephrine

Question 24

precursor of catecholimes

Answer 24

Tyrosine

Question 25

steps of catecholamines

Answer 25

1. hydroxylation: tyrosine --> dopa 2. decarboxylation: dopa --> DA

Question 26

norepinephrine

Answer 26

precursor is dopamine

Question 27

epinephrine

Answer 27

precurosr norepinephrine

Question 28

Degradation of catecholmines

Answer 28

1. MAO 2. COMT

Question 29

Steps of serotonin synthesis

Answer 29

1. hydroxylation (adding HO) 2. decarboxylation (take away

Question 30

precursor of serotonin

Answer 30

trytophan

Question 31

degradation of srotonin

Answer 31

degraded by MAO

Question 32

Amino Acids neurotransmitters

Answer 32

- glutamate - glycine - GABA

Question 33

glutamate

Answer 33

- main excitatory NT in the brain

Question 34

glycine

Answer 34

- inhibitory NT is found primarily in spinal cord, brainstem and retina

Question 35

GABA

Answer 35

- most common inhibitory Nt in the brain - epilepsy

Question 36

precursor to GABA

Answer 36

glutamate is the precursor to GABA - uses GAD (glutamic acid decarboxylase)

Question 37

neuropeptides

Answer 37

- substance P - opiod peptides (endorphines) - morphine and heroin are exogenous opioids and bind to opiod receptors - pain perception

Question 38

retrograde messenger

Answer 38

- endocannabinoids and nitric oxide are retrograde

Question 39

Agonists

Answer 39

- facillate postsynaptic effects - mimics effects of neurotransmitters

Question 40

antagonist

Answer 40

- drugs that prevent normal functioning of NT

Question 41

How drugs enhance transmission

Answer 41

- as precurosrs for synthesis - activatin receptors directly - block degrading enzymes - block reuptake - increase NT release

Question 42

how drugs inhibit transmission

Answer 42

- reducing synthesis - make vesicle leak - block receptors inhibite depolarization

Question 43

Ach synthesizing enzyme

Answer 43

choline acetyltransferas (ChAT)

Question 44

degrading of ACh

Answer 44

- broken by Aceylcholineterase (AChE) - broken into acetic acid and choline

Question 45

rate limiting step of ACh

Answer 45

bringing choline back in

Question 46

what does L-dopa treat and how

Answer 46

its used to treat parkinsons by increases DA available for release - l-dopa increases synthesis

Question 47

enzyme in hydroxylation of cathecolamines

Answer 47

tyrosine hydroxylase synthesizes tyrosine to dopa TH is the rate limiting step

Question 48

enzyme for dopa to da

Answer 48

dopa decarboxylase

Question 49

how do antipsychotics work

Answer 49

they block DA receptors and autoreceptors - DA antagonist

Question 50

how does cocaine work

Answer 50

blocks reuptake of dopamine

Question 51

enzyme for DA to NE

Answer 51

Dopamine-B-hydroxylase

Question 52

enzyme for NE to EPI

Answer 52

PNMT - degraded by MAO and COMT

Question 53

Prozac

Answer 53

- aka fluoxetine - blocks reuptake of serotonin which increases its levels -ssri

Question 54

antidepressant iproniazid

Answer 54

- blocks MAO inhibitors for serotonin

Question 55

excitotoxicity

Answer 55

when glutamate is in excessive quantities - can cause strokes

Question 56

Apomorphine acting of DA receptors

Answer 56

it activates the receptor directly

Question 57

amphetamine

Answer 57

increases DA release

Question 58

AMPT

Answer 58

reduces synthesis of DA by inhibits the enzyme TH