Neurotransmitters Flashcards
List 3 common neurotransmitters and state if excitatory or inhibitory? (3)
Acetylcholine (Ach)- excitatory in skeletal
- inhibitory in heart
Glutamate (GLU)- excitatory
GABA- inhibitory
What are neuromodulators?
Examples? (3)
Cause change in synaptic membrane
Longer lasting- slower events- i.e. learning, development
Dopamine (DA)
Noradrenaline (NA)
Serotonin
How do local anesthetic work?
Examples?
Procaine and lignocaine
Interrupting axonal neurotransmission
Block sodium channels- prevent depolarisation
Nociception cannot be transmitted
How do local anaesthetic worj?
Diffuse through mucus membranes
Can act on muscle
What are two types of neurotransmitter receptors?
Ligand-activated (ionotropic)
Metabotropic
What is ionotropic receptor (ligand activated)?
Ion channel proteins
Excitatory or inhib
Open due ligand binding
How do ionotropic receptors/ligand activated ion channels work?
1) Open directly response to ligand binding
2) Undergo change shape when neurotransmitter binds
3) Allow ion influx/efflux from cell
4) Produce quick response
What receptor causes quick response?
Ionotropic/ligand activated ion channels
What are metabotropic receptors?
Trigger signal pathways- not ion channels
Excitatory or inhibitory
How does metabotropic receptors work?
Can indirectly affect ion channel open/close
Tend involve second messenger
Slow
What is main inhibitory neurotransmitter?
GABA
What is main excitatory neurotransmitter?
Glutamate
Where can Ach act? (3)
PNS- neuromuscular junctions
Brain and spinal cord
What are neurons called release Ach?
Cholinergic neurons
What do cholinergic neurons release?
Ach
What breaks down Ach? Into?
Acetylcholinesterase
Breaks Ach into choline and acetate
What breaks down Ach?
Were is choline transported after broken down?
Acetylcholinesterase
Choline transported back to presynaptic axon terminal
Choline reused
What are two types Ach receptor?
Nicotinic
Muscarinic
What do nicotinic receptors respond to? (2)
Where is found?
Respond Ach and nicotine
Found NMJ
How do nicotinic receptors work?
1) Ach causes ion channels open
2) Depolarisation target cell
What function are nicotinic receptors important in?
Cognitive function and behaviour
What are muscarinic receptors?
Location?
Couple with G proteins
Brain
PNS innervates peripheral glands/organs- salivary gland
Not ion channel
Trigger signal pathways- inhibit ap
What receptors used with G proteins?
Muscarinic
What receptors used with ion channels?
Nicotinic
What transmitter/receptor/receptors used in skeletal? Effect?
Ach
Nicotinic
Ligand gated ion channel
Promotion muscle contraction
What transmitter/receptor/receptors used inhibit heart muscle? Effect?
Ach
Metabotropic receptor
Inhibit muscle contraction
Function neuroadrenaline?
Transmitted peripheral heart
CNS
Sympathetic- increase rate of contractions
What effects noradrenaline? eg
Antidepressant drugs
Imipramine- block reuptake NA
What stimulates noradrenaline?
Amphetamines
Increase release
Block reuptake
Where is dopamine located?
Basal ganglia
Substantia niagra
What is dopamine affected by? Examples
Antipsychotic drugs
Chlorpromazine- antagonist and block receptors
Function of chlorpromazine?
Antipsychotic drug
Dopamine antagonist- block receptor
What stimulates dopamine prod?
Amphetamines
What is serotonin function?
Excitatory effect pathways
What effects serotonin?
Antidepressant drug- Prozac
Increase conc. synaptic serotonin
What function Prozac?
Increase conc. synaptic serotonin
What is effect of ecstasy on serotonin?
Ecstasy is neurotoxic to serotonin neurons
Destroy terminal of axons
What does loss dopamine cause?
Alzheimer’s
