Studied by 1 personWhat is ACh function on the CNS?
Alterness
Attention
Memory
How is ACh synthesised?
Choline + acetyl CoA -> ACh using the enzyme choline acetyl transferase
Where is ACh located in the CNS?
Basal forebrain
Cerebral cortex
Hippocampus
What condition does an impaired levels of ACh cause?
Myasthenia gravis- autoantibodies to ACh receptors
ACh is also the neurotransmitter (NT) of the...
neuromuscular junction
What is ACh the final NT of?
ACH is the final NT in parasympathetic innervation pathways of the ANS
How is ACH recycles/ reuptaked?
ACh broken down to choline which is transported back into the pre-synaptic cleft for re-cycling into fresh ACh.
How is ACh cleared?
Acetylcholine esterase breaks ACh down before it activates receptors.
What are the ACh receptors?
Nicotine ACH R-ligand gated ion channels (fast)
Muscarinic ACh R-G protein coupled (slow)
Use 2nd messengers
What is noradrenaline function on the CNS?
Alterness
Arousal
Action readiness
How is noradrenaline synthesised?
Tyrosine -> Levodopa -> dopamine -> noradrenaline
Where is noradrenaline located in the CNS?
Medulla
Solitary nucleus
Locus coeruleus
What condition does an impaired levels of noradrenaline cause?
Sympathetic hyper-activation (multiple systems)
What is noradrenaline's role on the sympathetic nervous system?
It is the major NT in the SNS
Plays a major role in sympathetic innervation to the cardiovascular system
Controls vasomotor tone by activating alpha-adrenoceptors on VSMC.
How is noradrenaline recycles/ reuptake?
Noradrenaline (NorAd) transport into pre-synaptic cell or glia by noradrenaline transporters (NET).
How is NorAd cleared?
NorAd broken down by monoamine oxidase in cytosol (NOT synaptic cleft) + by catechol-O- methyltransferase
What are the NorAd receptors?
beta-adrenoceptors (1-3)
Gs- coupled
Alpha-adrenoceptor 1 (Gq- coupled)
Alpha- adrenoceptor 2 (Gi/O coupled)
What is dopamine function on the CNS?
Executive function
Motor control
Motivation
How is dopamine synthesised?
Phe -> Thy -> Levodopa -> Dopamine
Where is dopamine located in the CNS?
Substantia nigra
hypothalamus
VTA
Arcuate nucleus
Zona incerta
What condition does an impaired levels of dopamine cause?
Parkinson's disease (destruction of dopaminergic neurons in the substantial nigra)
Multiple sclerosis
Brain ageing
What type of behaviour is dopamine important in?
Reward-motivaiton behaviour
Many addictive drugs block dopamine re-uptake + increase its release
What does dopamine also influence?
Motor control
lactation (inhibit)
nausea
How is dopamine recycles/ reuptake?
Dopamine transport into the presynaptic cleft or glia via dopamine transporters + monoamine transporters
How is dopamine cleared?
Dopamine is broken down by monoamine oxidase in the cytosol (NOT cleft) + catechol- O methyl transferase
What are the dopamine receptors?
5 subtypes (all GPCR)
Different effects due to 2nd messenger system triggered after dopamine activation of receptors.
What is noradrenaline function on the CNS?
Note
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