Neurotransmitters

Question 1

name the parts of the neuron

Answer 1

dendrites, soma, axon, synaptic terminal

Question 2

why does a dendrite have spines?

Answer 2

increase surface area

Question 3

what happens in the dendrites?

Answer 3

information reception

Question 4

what happens in the soma?

Answer 4

integration of signals

Question 5

what happens in the axon?

Answer 5

rapid information transfer (action potential)

Question 6

how many ms does an action potential take to pass through one neuron to the next?

Answer 6

2

Question 7

how big is the synapse?

Answer 7

20-100nm

Question 8

which type of impulse does the dendrite usually receive?

Answer 8

excitatory

Question 9

which type of impulse does the soma usually receive?

Answer 9

inhibitory

Question 10

what happens in the presynaptic terminal?

Answer 10

biosynthesis, packaging and release of the neurotransmitter

Question 11

what happens when the neurotransmitter binds to the receptor?

Answer 11

activation

Question 12

what happens after receptor activation?

Answer 12

inactivation

Question 13

what are the three main types of neurotransmitter?

Answer 13

amino acids, amines and neuropeptides

Question 14

give an example of an amino acid neurotransmitter

Answer 14

glutamate, gamma amino butyric acid, glycine

Question 15

give an example of an amine neurotransmitter

Answer 15

noradrenaline, dopamine

Question 16

give an example of a neuropeptide neurotransmitter

Answer 16

opioid peptides

Question 17

Is glutamate excitatory or inhibitory?

Answer 17

excitatory

Question 18

Is GABA excitatory or inhibitory?

Answer 18

inhibitory

Question 19

where is glycine important as a neurotransmitter?

Answer 19

spinal cord

Question 20

where is noradrenaline an important neurotransmitter?

Answer 20

sympathetic nervous system

Question 21

does the parasympathetic nervous system slow or increase heart rate?

Answer 21

slows

Question 22

does the sympathetic nervous system slow or increase heart rate?

Answer 22

increases

Question 23

what is the variance of concentration of neurotransmitters in the CNS

Answer 23

nM to mM

Question 24

What is the range of speed of responses a neurotransmitter can produce?

Answer 24

microseconds to milliseconds (rapid) or seconds (slow)

Question 25

what does the action potential cause at the presynaptic terminal?

Answer 25

voltage gated calcium channels open, calcium influx into cell causing synaptic vesicle exocytosis

Question 26

what happens when an excitatory neurotransmitter binds to a receptor on the post synaptic membrane?

Answer 26

Na+ flows into cell, causing depolarisation and transmission of an action potential

Question 27

what happens when a reuptake protein on the presynaptic membrane takes in a neurotransmitter?

Answer 27

reloaded into vesicles

Question 28

what happens after the neurotransmitter is removed from the cleft?

Answer 28

sodium potassium pumps return membrane potential to resting

Question 29

what size increase in intracellular calcium concentration does transmitter release require?

Answer 29

less than 1micromolar to 200 micromolar

Question 30

how many molecules of transmitter in each pre-synaptic vesicle?

Answer 30

4,000-10,000

Question 31

how fast is influx of Ca2+ ions

Answer 31

ms down to 200microseconds

Question 32

what happens during the process of electromechanical transduction?

Answer 32

membrane depolarisation, Ca2+ channels open, Ca2+ influx, vesicle fusion, vesicle exocytosis, transmitter release

Question 33

how do the neurotransmitters get into the vesicles?

Answer 33

protein pumps

Question 34

what allows the docking of vesicles?

Answer 34

vesicle proteins

Question 35

what does alpha latrotoxin do and where is it found?

Answer 35

stimulates transmitter release to depletion and produced by black widow spider

Question 36

what do zinc dependent endopeptidases do and give two examples and what they cause

Answer 36

inhibit transmitter release, tetanus toxin - causes paralysis, botulinum toxin C causes flaccid paralysis

Question 37

Is vesicle docking and exocytosis an active or passive process and what does it require?

Answer 37

active, ATP

Question 38

How are vesicles replenished?

Answer 38

vesicle recycling - protein pumps fill them up

Question 39

what are the two main classes of neurotransmitter receptor? Relative speed of responses?

Answer 39

ion channel receptor - fast, g-protein coupled receptor -slow

Question 40

what are the main effectors of the G protein coupled receptor?

Answer 40

enzymes or channels

Question 41

glutamate and gamma amino butyric acid use which kind of receptor in the CNS?

Answer 41

ion channel

Question 42

ACh at the neuromuscular junction binding nicotinic receptors uses which kind of receptor?

Answer 42

ion channel

Question 43

G-protein coupled receptor is used for which neurotransmitters and where?

Answer 43

In the CNS and peripheral nervous system, | ACh at muscarinic receptors in heart tissue, dopamine, noradrenaline, serotonin and neuropeptides

Question 44

what is the advantage of multiple subunit combinations (5 types of subunit) in an ion channel?

Answer 44

distinct functional properties

Question 45

Depolarisation or hyperpolarisation? Glutamate GABA Glycine

Answer 45

Depolarisation (Na+) Hyperpolarisation (Cl-) Hyperpolarisation (Cl-)

Question 46

What are the two main types of glutamate receptors?

Answer 46

AMPA and NMDA

Question 47

AMPA receptors are what kind?

Answer 47

rapid excitatory

Question 48

NMDA receptors are what kind?

Answer 48

slow component of excitatory transmission

Question 49

Which ion(s) do AMPA receptors allow influx of and what is the rate of onset, offset and desensitisation?

Answer 49

Na+, rapid

Question 50

Which ion(s) do NMDA receptors allow influx of? What is their role in the body?

Answer 50

Ca2+ and Na+ | Serve as coincidence receptors which underly learning mechanisms

Question 51

what is a coincidence receptor?

Answer 51

It relies on pre-depolarisation of the post-synaptic membrane to work

Question 52

how is glutamate reuptaken?

Answer 52

into pre-synaptic bulb and into glial cells

Question 53

how is glutamate modified in the glial cells?

Answer 53

glutamine synthetase modifies glutamate to glutamine

Question 54

what happens if there is excess glutamate in the brain?

Answer 54

GABA neurons are stimulated

Question 55

What happens if excess glutamate levels are not decreased or GABA is not released?

Answer 55

abnormal cell firing leading to seizures

Question 56

as the glutamate level comes down, what happens to glutamine levels?

Answer 56

they increase slowly as glutamate is broken down

Question 57

how many people worldwide are affected by epilepsy?

Answer 57

50 million

Question 58

how many epilepsy seizures are refractory to treatment?

Answer 58

25-30%

Question 59

How is GABA formed?

Answer 59

decarboxylation of glutamate by glutamic acid decarboxylase (GAD)

Question 60

which enzyme in the glial cells breaks down GABA?

Answer 60

GABA transaminase

Question 61

How many subunits make up a GABA a receptor?

Answer 61

5

Question 62

which 4 types of drugs facilitate GABA transmission?

Answer 62

antiepileptic anxiolytic sedative muscle relaxant