Neurochemistry Flashcards
Area within the synaptic terminal where a neurotransmitter is stored
Synaptic vesicle
Processes required for release of the neurotransmitter to the postsynaptic neuron
Membrane fusion
Exocytosis
Area the neurotransmitter occupies post synapse
Postsynaptic neuronal membrane
Activity the neurotransmitter has on the presynaptic neuron which is important for feedback inhibition
Autoreceptor activity
Model for the idea that only a particular chemical shape can be accommodated by a particular receptor site
Lock and key
Type of binding of neurotransmitters where the receptor changes back to its previous state once the neurotransmitter breaks down
Reversible
Type of binding where the neurotransmitter structurally alters the receptor site
Irreversible
Idea that the relative concentrations of different molecules decide what binds to the receptor
Competitive receptor binding
Ways a neurotransmitter can cease to be active at a receptor site
Reuptake back to the presynaptic neuron
Enzymatic breakdown
Removal by glia or plasma circulation
Neurotransmitters that are monoamines
Dopamine Adrenaline Noradrenaline Serotonin Histamine
Neurotransmitters that are amino acids
GABA
Glycine
Glutamate
Aspartate
Neurotransmitters that are peptides
Endorphins Cholecystokinin Neurotensin Neuropeptide Y Leptin Ghrelin
Three categories of receptors
Ligand gated - ionotropic
G protein coupled - metabotropic
Nuclear
Speed of response of ionotropic vs. metabotropic recptors
Ionotropic faster than metabotropic
Ion that enters in inhibitory neurotransmitter action of ionotropic receptors
Cl-
Ion that enters in excitatory neurotransmitter action on ionotropic receptors
Ca2+ or other cations
Examples of ionotropic receptors
GABA a
NMDA
5HT3
Excitatory proteins that act on metabotropic receptors
Gs
Inhibitory proteins that act on metabotropic receptors
Gi
Examples of metabotropic receptors
Dopamine receptors
5HT receptors except 5HT3
Opioid receptors
Substances made in the synthesis of dopamine
Phenylalanine (essential amino acid)
Tyrosine (can also start with tyrosine, a non-essential amino acid)
L-dopa
Dopamine
Enzyme which is the rate limiting step in synthesising dopamine
Tyrosine hydroxylase
Enzymes which degrade dopamine
Monoamine oxidase (MAO B more than MAO A) Catechol-o-methyl transferase (COMT)
End product of dopamine breakdown
Homovanillic acid
Reuptake method for dopamine
Dopamine transporter
Effect of cocaine on the reuptake of dopamine
Inhibits it
Function of dopamine
Motivation Novelty seeking Reward circuit Arousal Motor movement in basal ganglia
Dopamine receptors
D1 - D5
Two major types of dopamine receptors
D1 like - D1 and D5
D2 like - D2, D3 and D4
Category of receptor the dopamine receptors fit into
G protein coupled receptors
Effect of D1 like dopamine receptors
Excitatory
Increase adenylate cyclase
Effect of D2 like receptors
Inhibitory
Decrease adenylate cyclase
Part of the brain D4 is primarily found
Frontal cortex
Dopamine receptor clozapine has a high affinity for
D4
Level of dopamine in Parkinson’s disorder
Low
Level of dopamine in psychosis
High
Area of raised dopamine in psychosis
Mesolimbic area
Substances made in the synthesis of noradrenaline/adrenaline
Phenylalanine (essential amino acid) Tyrosine (can start directly with tyrosine - non-essential amino acid) L-dopa Dopamine Noradrenaline Adrenaline
Rate limiting enzyme in the synthesis of noradrenaline/adrenaline
Tyrosine hydroxylase
Enzyme for the conversion of dopamine to noradrenaline
Dopamine-b-hydroxylase
Enzyme for the conversion of noradrenaline to adrenaline
Phenylethanolamine-N-methyltransferase
Enzymes which degrade noradrenaline
MAO (MAO A more than MAO B)
COMT
Breakdown products of noradrenaline
3-methoxy-4-hydroxyphenylglycol (MHPG)
Vanillyl mandelic acid (VMA)
Major metabolite of noradrenaline in the CNS
MHPG
Major metabolite of noradrenaline in the peripheral nervous system
VMA
Reuptake method of noradrenaline
Noradrenaline reuptake channel
Effect of tricyclics on the reuptake of noradrenaline
Inhibis
Effect of reboxetine on the reuptake of noradrenaline
Inhibits
Function of noradrenaline
Arousal
Anxiety
Sympathetic effects - increase in blood pumped, increase in BP, increase in glucose production, increase in glucose uptake by skeletal muscles
Noradrenaline receptors
Alpha 1 Alpha 2 Beta 1 Beta 2 Beta 3
Effect of alpha 1 noradrenaline receptors
Activate phospholipase C
Effect of alpha 2 receptors
Inhibit adenylate cyclase - act as presynaptic autoreceptors
Levels of noradrenaline in depression
Low
Levels of noradrenaline in panic/anxiety disorder
High
Substances made in the synthesis of serotonin
Tryptophan (essential amino acid)
5 hydroxy l-tryptophan
Serotonin
Rate limiting step in synthesis of serotonin
Availability of tryptophan
Enzyme involved in the synthesis of serotonin from 5 hydroxy l-tryptophan
Tryptophan hydroxylase
Enzymes involved in the breakdown of serotonin
MAO - more MAO A than MAO B
Breakdown product of serotonin
5-hydroxyindoleacetic acid (5-HIAA)
Reuptake method for serotonin
Serotonin reuptake channel
Effect of SSRIs on reuptake of serotnin
Block