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HHD 2 > Neurotransmission > Flashcards

Neurotransmission Flashcards

1
Q

What is neurotransmission?

A

The process by which neurons communicate with one another across synapses using neurotransmitters (endogenous chemical messenger)

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2
Q

What is the resting membrane potential of a neuron

A

-70mV

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3
Q

What is the function of the Na+/K+ ATPase pump?

A

Uses energy from ATP to move out 3 Na+ ions and move in 2 K+ ions against their concentration gradient

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4
Q

What is the function of potassium leak channels?

A

move K+ ions out of the cell down its concentration gradient

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5
Q

A- proteins are permeable and can leave the cell. True or false

A

False
Impermeable, cannot leave the cell

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6
Q

How is the resting membrane potential of a neuron kept negative?

A
  • Na+/K+ ATPase pump
    -potassium leak channels
  • A- proteins
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7
Q

Briefly state the stages of an action potential

A
  1. Resting potential
  2. Depolarization (threshold potential)
  3. Repolarization
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8
Q

What is the threshold potential of neurones ?

A

-55mV
When the threshold potential is reached an all or nothing action potential is fired

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9
Q

During repolarisation, hyperpolarisation briefly occurs. Describe hyperpolarisation.

A

Hyperpolarisation is also known as the refractory period. At this point no other action potential can be reached.
During hyperpolarisation, the membrane potential goes past -70mV however gradually over time ion concentrations return to resting levels and the membrane potential returns to -70mV

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10
Q

What is an inhibitory post synaptic potential (IPSP)?

A

a temporary hyper-polarization of the post synaptic membrane caused by flow of negatively charged ions (e.g. Cl-) into the post synaptic cell

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11
Q

What is an excitatory post synaptic potential (EPSP)?

A

these are synaptic inputs that induce depolarisation of the membrane, bringing potential to the threshold potential and closer to firing the action potential

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12
Q

What is the result of an action potential in a neuron?

A

release of neurotransmitters

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13
Q

What are the classifications of main neurotransmistters?

A

Amino acid
Monoamines
Peptide

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14
Q

Amino acid neurotransmitters are able to carry out most functions. Give examples of amino acid neurotransmitters.

A

Glutamate
GABA
Glycine

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15
Q

What are the main functions of monoamine neurotransmitters?

A

Attention
Cognition
Emotion

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16
Q

Give examples of monoamine neurotransmitters

A

Serotonin
Histamine
Dopamine
Adrenaline
Noradrenaline

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17
Q

What is the main function of peptide neurotransmitters?

A

Pain

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18
Q

Give examples of peptide neurotransmitters

A

Opioids (endorphins)

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19
Q

“Other” neurotransmitters include acetylcholine. Briefly state some functions of this neurotransmitter

A

Autonomic nervous system
Motor nerves

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20
Q

How is glutamate synthesized?

A

glutamate can be generated from glutamine by the action of glutaminase in the mitochondria

glutamate can also be generated by the transamination of aspartate or alanine

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21
Q

Glutamate is stored in the synaptic vesicles and released following __________.

A

Ca2+ (calcium ion) influx

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22
Q

How is glutamate metabolised?

A

Glutamate is primarily takend up by GLT-1 and GLAST transporter proteins located on adjacent glial cells

The glutamate is converted into glutamine in the glial cells

Glutamine is then taken back up by neurones and is converted in the mitochondria to glutamate

Some neurones also express EAAC1 which recycles glutamate directly

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23
Q

Glutamate receptor are ________ receptors. What kind of receptors are they?

A

Ionotrophic and metabotropic

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24
Q

Describe the structure of glutamate receptors

A

Form tetrameric complexes with a central pore
each subunit consists of a transmembrane domain, ligand binding domain and an extracellular N terminal domain

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25
Q

Give examples of glutamate receptors

A

NMDA
AMPA
Kainate

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26
Q

What is required for NMDA activation ?

A

Simultaneous binding of glutamate and glycine neurotransmitters

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27
Q

What prevents excessive activation of NMDA receptor ?

A

magnesium ion blocking the ion channel
Voltage dependent Mg2+ block

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28
Q

Briefly describe the permeability of NMDA receptors to Ca2+ ions

A

Highly permeable

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29
Q

NMDA receptors have a slow activation-deactivation (ms) and weak desensitisation. True or false

A

True

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30
Q

What are the possible subunits for an NMDA receptor?

A

N1-N3
N1
N2
N3
2 N1 subunits present
2 N2/N3 subunits present

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31
Q

AMPA glutamate receptors have fast activation- deactivation and strong desensitisation. True or false

A

True

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32
Q

Describe the permeability of AMPA receptors to Ca2+ ions

A

less permeable

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33
Q

What are the possible subunits for AMPA receptors

A

A1- 4
A1
A2
A3
A4

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34
Q

Kainate glutamate receptors constitute ____ possible subunits

A

5
K1
K2
K3
K4
K5

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35
Q

What is thought to contribute to cell death in a number of neurological disorders including alzheimers, huntingtons, parkinsons, stroke and MS?

A

NMDA-R mediated Ca2+ overload

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36
Q

What can be used pharmacologically to combat NMDA-R mediated Ca2+ overload?

A

Ketamine
Memantine

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37
Q

What is ketamine?

A

a non-competitive open channel blocker

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38
Q

Ketamine is licensed for use for…

A

the induction and maintenance of anaesthesia
may also be useful as an analgesic and in the treatment of major depressive disorder

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39
Q

What is memantine?

A

Non-competitive open channel blocker

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40
Q

Memantine is currently used to treat …

A

moderate to sever alzheimers

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41
Q

Memantine is a ______ affinity NMDA receptor antagonist

A

low affinity

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42
Q

Briefly describe the on and off kinetics of memantine

A

fast on-off kinetics

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43
Q

What is the consequence of AMPA and Kainate receptor over-activation?

A

glutamate induced neurotoxicity

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44
Q

Antagonists of glutamate are _____________. They help reduced ischaemia induced white matter injury.

A

neuroprotective

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45
Q

List drugs that act on AMPA and Kainate receptors

A

Topiramate
Perampanel
Texampanel

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46
Q

Topiramate inhibits which receptors? What is its clinical use?

A

inhibits both AMPA and kainate receptors
licensed for use as an adjunct for epileptic seizures and prophylaxis of migraine

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47
Q

What is perampanel?

A

A highly selective non competitive AMPA antagonist

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48
Q

What is the current clinical use of perampanel ?

A

adjunct for epileptic seizures

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49
Q

Tezampanel is more selective for which receptor?

A

Kainate receptor

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50
Q

What is the current clinical use of tezampanel?

A

currently being investigated for treatment of migranes

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51
Q

Where is the glutamate binding site on metabotropic glutamate receptors?

A

between the two lobes of the VFT domains
(venus fly trap)

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52
Q

Where are metabotropic glutamate receptors primarily located?

A

presynaptically

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53
Q

Metabotropic glutamate receptors play an important role in _________.

A

Long term depression (LTD)

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54
Q

Metabotropic glutamate receptors are grouped into 3 classes. What are group I metabotropic receptors ?

A

mGlu1 and mGlu5
Gq linked to PI-PLC pathway (phosphoinositide- phospholipase C)

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55
Q

Metabotropic glutamate receptors are able to form ___________ structures

A

heterodimeric

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56
Q

mGlu5 antagonists are thought to…

A

reverse intellectual disability
Fragile X syndrome

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57
Q

What is the function of metabotropic glutamate receptors?

A

they have been known to modulate the activity of other receptors e.g. modulation of NMDA-R

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58
Q

What receptors/variants are in group II mGLuRs ?

A

mGlu2
mGlu3

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59
Q

Group II and III mGluRs are linked to…

A

Gi- inhibition of adenylate cyclase

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60
Q

What receptors/variants are in group III mGluRs?

A

mGlu4
mGlu6
mGlu7
mGlu8

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61
Q

Positive modulators of group II mGluRs are being investigated for …

A

schizophrenia

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62
Q

Positive modulators of what group III variant is being investigated for treatment of parkinsons?

A

mGlu4

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63
Q

GABA is synthesised from _______ by the action of what enzymes?

A

Glutamate
Glutamic acid decarboxylase enzyme (GAD)

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64
Q

GAD (Glutamic acid decarboxylase enzyme) is comprised of two different molecular weights. What are the molecular weights?

A

65kDa
67kDa

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65
Q

What is the major isoform of GAD enzyme in the brain?

A

GAD65

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66
Q

The majority of the GAD65 isoform is inactive. True or false

A

True

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67
Q

During metabolism of GABA, the majority of GABA is taken up by ______ in _________ and repackaged.

A

GABA transporters- GAT
in Presynaptic terminals

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68
Q

What enzyme catabolises GABA to glutamine ? Where is this enzyme found?

A

GABA transaminase (GABA-T)
found in glial cells

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69
Q

GABA ionotropic receptos belong to what family of receptors? What do they form?

A

Cys- loop family of receptors
They form pentameric complexes with a central pore

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70
Q

Each subunit of GABA ionotropic receptors consists of…

A

Extracellular ligand binding domain
Transmembrane domain with 4 transmembrane alpha helices

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71
Q

GABAa ionotropic receptor is permeable to what ion?

A

Chloride

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72
Q

GABAa receptors are assemblies of what subunits?

A

alpha 1-6
beta 1-4
gamma 1-4
delta
epsilon
pie
theta
rho

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73
Q

GABAa receptors are usually composed of 5 subunits. What are the most common subunits for a GABAa receptor?

A

2alpha
2 beta
1 gamma

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74
Q

How many binding sites for GABA are present on a GABAa receptor? What are there referred to as?

A

2
alpha-beta interface

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75
Q

GABAa receptors also contain a benzodiazepine site to enable benzodiazepine binding. What is this referred to as?

A

alpha- gamma interface

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76
Q

GABAc ionotropic receptors are chloride permeable ion channels that are composed entirely of _____ subunits.

A

Rho subunits

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77
Q

Where are GABAc ionotropic receptors expressed?

A

Expressed exclusively in the retina

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78
Q

GABAa receptors are allosterically modulated by what chemicals/compounds?

A

Benzodiazepines

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79
Q

An example of a benzodiazepine is…

A

Diazepam

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80
Q

What subunits are important in benzodiazepine binding to GABAa receptors?

A

Alpha 1,2,3 AND 5
Beta
Gamma 2

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81
Q

Benzodiazepines are useful in the treatment of…

A

seizures
anxiety
insomnia
alcohol withdrawal
muscle spasms

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82
Q

What subunit of GABAa receptors mediates the sedative effects of benzodiazepines?

A

Alpha 1 subunits

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83
Q

What subunits of GABAa receptors mediate the anxiolytic effects of benzodiazepines?

A

alpha 2 and 3

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84
Q

What is the effect on barbiturates on GABAa receptors?

A

they can stimulate channel opening independent of GABA binding at a concentration >50uM

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85
Q

An example of a barbiturate used to treat epilepsy is…

A

Phenobarbital

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86
Q

An example of a barbiturate that is used as an anaesthetic is…

A

Thiopental

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87
Q

What is the effect of steroids such as progesterone derivative on GABAa receptors ?

A

they are able to open the channel directly
at a concentration >50uM

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88
Q

What progesterone derivative is in trials for treatment of epilepsy?

A

Ganaxolone

89
Q

Anaesthetics such as propofol and etomidate allosterically modulate GABAa receptors. Their action is thought to involve what subunit?

A

Beta 3 subunit

90
Q

What are the two isoforms of GABAb receptors?

A

GABAbR1
GABAbR2

91
Q

The isoforms of GABAb receptors are only able to form functional receptors when they are…

A

dimers

92
Q

GABAb receptors are ________ receptors. What is their function

A

Metabotropic receptors (GPCRs)
their function is to modulate ion channel activity

93
Q

What is the function of pre-synaptic GABAb receptors?

A

to reduce multi-vesicular release of glutamate (inhibit VGCC)
inhibition of voltage gated calcium channels- preventing influx of calcium ions

94
Q

What is the function of post synaptic GABA receptors?

A

to reduce neuronal excitability by enhancing K+ channel activity and reducing Ca2+ channel activity through Gbetagamma subinits (G protein beta and gamma subunits)

95
Q

GABAb receptors have also been linked to the inhibition of adenylal cyclase enzyme through the action of what proteins?

A

Gi proteins

96
Q

What is baclofen?

A

an agonist for GABAb receptors
used as a skeletal muscle relaxant and used to treat severe chronic spasticity

97
Q

Where is glycine found?

A

spinal cord and brain stem

98
Q

What physiological functions is NT glycine involved in?

A

reflex responses
processing sensory signals
pain sensation

99
Q

What is the predominant trasnsporter in presynaptic terminals of glycinergic neurones?

A

GLYT2 transporter

100
Q

What is the predominant glycine transporter in glial cells?

A

GLYT1 transporters

101
Q

Glycine can be metabolised by ______

A

glycine decarboxylase system

102
Q

Glycine receptors belong to what family?

A

Cys-loop ligand gated ion channel

103
Q

Glycine receptors are permeable to ____ ions which lead to __________.

A

Cl-
hyperpolarisation

104
Q

What subunits have been identified to form glycine receptors?

A

Four alpha subunits
One beta subunit

105
Q

Inherited mutations to the human Glycine receptor genes give rise to what condition?

A

Hyperekplexia
An exagerrated surprise/pronounced startle: newborns

106
Q

RG1678 is a __________. It is currently in clincial trials for the treatment of ___________.

A

GLYT1 (glial cells) inhibitor
Schizophrenia

107
Q

Briefly state the synthesis of Dopamine

A

L-tyrosine —> L-DOPA —>Dopamine

108
Q

What enzymes are involved in the synthesis of dopamine

A

Tyrosine hydroxylase
DOPA decarboxylase

109
Q

Dopamine can be removed from the synaptic cleft by…

A

Dopamine transporter (DAT)
Noradrenaline transporter (NET)

110
Q

What are the 3 enzymes that are involved in the metabolism of dopamine?

A

Monoamine oxidase A (MAO-A)
Monoamine oxidase B (MAO-B)
Catechol-O-methyl transferase (COMT)

111
Q

Where are MAO-A enzymes located?

A

Mitochondria

112
Q

MAO-A metabolises what monoamines?

A

Dopamine
Noradrenaline
Histamine

113
Q

MAO-B metabolises …

A

Dopamine

114
Q

COMT enzymes are widely distributed. What are they responsible for metabolising?

A

All cathecholamines
Dopamine
Noradrenaline
Adrenaline

115
Q

Dopamine receptors are metabotropic 7 TM GPCRs which are involved in …

A

Locomotor activity
Reward and reinforcement
Learning and memory
Psychosis

116
Q

What dopamine receptors are involve in locomotor activity ?

A

D1
D2
D3

117
Q

What dopamine receptors are involved in reward and reinforcement?

A

D1
D2

118
Q

What dopamine receptors are involved in learning and memory?

A

D1
D2

119
Q

What dopamine receptors are involved in psychosis?

A

D2

120
Q

Dopamine receptors are subdivided into D1- like and D-2 like receptors. What are the D1-like receptors

A

D1
D5

121
Q

D1-like dopamine receptors are linked to what type of G protein?

A

Gs linked
D5 receptors also linked to Gq proteins

122
Q

D1 receptor expression is found in what areas?

A

Nigrostriatal
Mesolimbic
Mesocortical areas

123
Q

D2 like receptors are ________. What kind of G proteins are they linked to ?

A

Inhibitory
Gi

124
Q

D2 like dopamine receptors include…

A

D2
D3
D4

125
Q

D2 receptors are expressed in…

A

striatum
nucleus accumbens
olfactory tubercle

126
Q

D3 dopamine receptors are expressed in …

A

limbic areas

127
Q

D4 dopamine receptors are lowly expressed in …

A

the CNS

128
Q

Enhanced ____ sensitivity is observed in schizophrenia

A

D2

129
Q

Dopamine receptors are involved in…

A

wakefulness (arousal)
mood
emotion

130
Q

Dopamine receptors also have a role in the secretion of what hormone?

A

prolactin
hormone involved in lactation (milk production)

131
Q

What is the functional role of dopamine receptors in the cortex?

A

arousal
mood

132
Q

What is the dominant D1 like type dopamine receptor in the cortex?

A

D1

133
Q

What D1 and D2 dopamine receptors are absent in the cortex

A

D5 (D1 LIKE)
D3 (D2 like)

134
Q

What is the functional role of dopamine in the limbic system?

A

Emotion
Stereotypic behaviour

135
Q

All D1 and D2 types of dopamine receptors are present in the limbic system. True or false

A

True

136
Q

List some agonists for dopamine receptors

A

Apomorphine
Bromocriptine
Ropinirole

137
Q

What is apomorphine?

A

non selective dopamine agonists used to treat parkinsons disease

138
Q

What is bromocriptine?

A

D2 agonist used to treat parkinsons disease and endocrine disorders such as acromegaly

139
Q

What is acromegaly ?

A

endocrine disorder where the body produces too much growth hormone

140
Q

What is ropinirole?

A

D2 like receptor agonist (D2, D3 D4) used to treat parkinsons disease and restless leg syndrome

141
Q

Give an example of a 1st generation antipsychotic which is a D2 receptor antagonist

A

Haloperidol

142
Q

Give an example of a 2nd generation antipsychotic drug which is a D2 receptor antagonists

A

Clozapine

143
Q

What are anti-emetic drugs?

A

Anti-sickness drugs
prevent nausea and vomiting

144
Q

Domperidone is an anti-emetic drug that blocks ______ receptors in the _________

A

D2 and D3 receptors
in the chemoreceptor trigger zone (CTZ)

145
Q

Metoclopramide is an anti-emetic that primarily blocks which dopamine receptor?

A

D2 receptor

146
Q

Give examples of dopamine antagonists that are used to treat depression and schizophrenia?

A

Flupentixol
Quetiapine
Affect multiple dopamine receptors

147
Q

Briefly state the synthesis of noradrenaline

A

L-tyrosine –> L-DOPA –> dopamine –> noradrenaline

148
Q

The synthesis of noradrenaline utilises which enzyme?

A

Dopamine B-hydroxylase

149
Q

How is noradrenaline removed from the synaptic cleft?

A

Noradrenaline transporter (NET)

150
Q

What enzymes are involved in the metabolism of noradrenaline?

A

MAO-A
COMT

151
Q

Noradrenaline alpha receptors are ______ receptors

A

Metabotropic GPCRs
7TM GPCRs

152
Q

Where are Noradrenaline alpha receptors primarily expressed?

A

smooth muscle in the periphery

153
Q

What is prazosin?

A

it is a noradrenaline a1 specific blocker used to treat hypertension and congestive heart failure

154
Q

What are the characteristics of a1 noradrenaline receptors

A

Ga linked
3 subtypes (1a, 1b and 1d)

155
Q

Noradrenaline a1b receptor has been suggested to be involved in …

A

addiction
seizures
neurodegeneration

156
Q

What are some characteristics of a2 noradrenaline receptors?

A

Gi linked
2a, 2b and 2c

157
Q

What is the function of alpha2 noradrenaline receptors

A

act as autoreceptors inhibiting the release of various neurotransmitters

158
Q

What are agonists of alpha 2 noradrenaline receptors used for?

A

used to treat recurrent migraines and alcohol withdrawal symptoms

159
Q

Give an example of a alpha 2 noradrenaline receptor agonist

A

Clonidine

160
Q

Beta receptors of noradrenaline are also 7 TM GPCRs. What G proteins are they associated with?

A

Gs proteins

161
Q

Antagonists of noadrenaline Beta receptors have been licensed for the treatment of which conditions. Give examples of a drug for each condition.

A

Anxiety- propanolol
migraines- nadolol, timolol
hyperthyroidism- metoprolol

162
Q

What is the function of B1 noradrenaline receptors

A

Retrieval of contextual and spatial memories but not emotional memories

163
Q

Acute stress can impair memory retrieval through B2 receptors. True or false

A

True

164
Q

Noradrenaline activated neurogenesis in hippocampal neurones through which noradrenaline receptor?

A

B3 receptor

165
Q

How is serotonin (5HT) synthesised?

A

from tryptophan (Trp)
transported into the brain utilising a neutral amino acid carrier

166
Q

What enzymes are involved in synthesis of 5HT

A

Trp –> 5-hydroxytryptophan (5HTP) by tryptophan hydroxylase
5HTP—> 5HT (hydroxytryptamine) by aromatice amino acid decarboxylase (AADC)

167
Q

How is 5-HT taken up into vesicles ?

A

by vesicular monoamine transporter-2

168
Q

How is 5-HT taken back into nerve terminals and glial cells?

A

Active transport via SERT (serotonin transporter)

169
Q

How is 5-HT metabolised?

A

MAO-A

170
Q

What physiological processes are 5-HT involved in?

A

sleep
appetite
thermoregulation
pain perception

171
Q

What disorders is 5-HT involved in?

A

Migraines
Depression
Psychosis
Drug abuse

172
Q

5-HT4 receptors are …

A

Heteroreceptors

173
Q

5-HT6 receptors have ________ locations

A

heterologous dendritic locations

174
Q

Where are 5-HT7 receptors mainly located ?

A

soma and axon terminals of GABAergic neurones

175
Q

What 5-HT receptors are Gas linked?

A

5-HT4, 5-HT6, 5-HT7

176
Q

What 5-HT receptors are Gai linked?

A

5-HT1A
5-HT1B
5-HT1D
5-HT1E
5-HT1F

177
Q

5-HT1A receptors have both ____ and ____ locations. What is their effect on neuronal firing?

A

Pre and post synaptic location
inhibit neuronal firing

178
Q

5-HT1B and 5-HT1D are _______. What is their function ?

A

heteroreceptors
inhibit neurotransmitter release

179
Q

What 5-HT receptors are Gaq linked?

A

5-HT2A
5-HT2B
5-HT2C

180
Q

5-HT2A receptors have ______ locations. What is their possible function?

A

somato-dendritic locations
May modulate glutamate release

181
Q

Give examples of antipsychotic drugs which antagonise 5-HT receptors and the receptors they block

A

Olanzapine - 5-HT2A, 5-HT2C
Quetiapine- 5-HT1A, 5-HT2A
Risperidone- 5-HT2A, 5-HT2C

182
Q

What is buspirone?

A

partial agonist of 5-HT1A receptor
Licensed for short term treatment of anxiety

183
Q

What are agonists of the 5-HT1B and 5-HT1D receptors? What are they used to treat ?

A

Triptans
Sumtriptan
Zolmitriptan
Acute migraines and cluster headaches

184
Q

Lorcaserin is a _________ agonist. What is its current clinical use?

A

Selective 5-HT2C agonist
reduces appetite so being investigated for treatment of obesity

185
Q

Xaliproden is a ________ agonist. What is its proposed clinical use?

A

5-HT1A agonist
Showed neuro-protection in vivo, investigated for treatment of alzheimers disease

186
Q

What 5-HT receptors are cation selective channels that belong to the ligand gated ion channel family ?

A

5-HT3 receptors

187
Q

How many 5-HT3 receptors are there? Name them

A

5
5-HT3A, B, C, D, E

188
Q

5-HT3A subunits can form what kinds of receptors?

A

Homomeric
Heteromeric receptors (other subunits)

189
Q

Where do 5-HT antagonists bind?

A

A-A- interface in 5-HT3A/3B receptors
(3A-3A)

190
Q

List some 5-HT3 antagonists

A

Granisetron
Ondensetron
Palonosetron

191
Q

Granisetron is …

A

a selective antagonists used to treat post-operative and chemotherapy induced nausea and vomiting

192
Q

Ondensetron is licensed to treat…

A

different types of nausea and vomiting
being investigated for neuropsychiatric disorders and alcoholism

193
Q

Palonosteron is a …

A

2nd generation 5-HT3 antagonist with higher affinity and longer half life used to treat chemotherapy induced nausea and vomiting

194
Q

How is histamine synthesised?

A

synthesised from histidine by histidine decarboxylase

195
Q

How is histamine inactivated in the synaptoc cleft?

A

By neuronal histamine N methyltransferase (HNMT)

196
Q

What are the histamine receptors?

A

There are 4 TM histamine receptor types
H1R-H4R

197
Q

What histamine receptors are expressed in abundance in the brain?

A

H1R-H3R

198
Q

What histamine receptors are coupled to Gq proteins ?

A

H1R

199
Q

H2R histamine receptors are coupled to _____ proteins. What kind of activity do they exhibit?

A

Gs
Constitutive

200
Q

H3R histamine receptors are coupled to _____ proteins. They have a degree of ______ activity in vivo

A

Gi/o
constituitive

201
Q

H4R histamine receptors are coupled to what G proteins? Where are they found?

A

Gi/o
mainly in periphery

202
Q

What histamine receptor has a high degree of similarity to the H3Rs?

A

H4Rs

203
Q

What is pitolisant ?

A

inverse H3R receptor agonis
licensed for treatment of nacrolepsy in US
in clinical trials for AD and schizophrenia

204
Q

Acetylcholine is synthesised from _____ by ________.

A

choline and acetyl CoA
Choline acetyl transferase enzyme (ChAT)

205
Q

How is Ach metabolised in the synaptic cleft?

A

acetylytransferase enzyme
products taken back up into nerve terminals

206
Q

Acetylcholinesterase is inhibited by drugs used to treat what conditions? Give examples

A

Alzheimers disease- Donepezil (improves cognition and behaviour)
Myasthenia Gravis- Neostigmine (improves muscle tone)

207
Q

What are nicotinic ACh receptors?

A

Cation selective channel that belongs to the cys-loop ligand gated ion channel family

208
Q

What is varenicline?

A

partial agonist of a4B2 nicotinic ACh receptor
full agonist at a7 receptor
licensed for treatment for smoking cessation
under investigation for schozophrenia as an adjunct, cocaine dependence

209
Q

What is bupropion?

A

non competitive nicotinic receptor antaginist
inhibits DAT and NET (dopamine and noradrenaline transporters)
used as treatment for nicotine addiction

210
Q

ACh muscarinic receptors are…

A

metabotropic
7TM GPCRs

211
Q

Muscarinic antagonist are used as …

A

bronchodilators
Ipatropium
Tiotropium

212
Q

Muscarinic agonists are used to treat _____

A

glaucoma (pilocarpine)
urinary retention (bethanechol)

213
Q

What are the Gq linked muscarinic ACh receptors?

A

M1-M3 and M5 isoforms

214
Q

Numerous M1 receptors blockers have been developed and successfully used to treat AD. True or false

A

False
They are ineffective

215
Q

What muscarinic ACh receptors are Gi linked?

A

M2 and M4

216
Q

What is the effect of Gi linked receptors?

A

Lead to inhibition of Adenylyl cyclase

217
Q

What is the effect of Gq linked receptors?

A

Activation of PLC
IP3 and DAG production
Mobilisation of calcium ions

218
Q

Xanomeline is a muscarinic ACh agonist. What isoforms have a preference for Xanomeline?

A

M1 and M4

HHD 2 (37 decks)

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