Neurotransmitters Flashcards
what are the two types of synapses
electrical synapses and chemical synapses
what is an electrical synapse
two neurons are connected by a gap junction which allows electrical current to flow directly from one cell to the other
what is a chemical synapse
release neurotransmitters from presynaptic membrane and bind to receptors on postsynaptic membrane
what is quanta
the amount of NT packaged into the vesicle
what do EPSPs/IPSPs modulate
the postsynaptic cell
what is the mechanism by which transmitters are released through exocytosis
SNARE proteins in the SV and plasma membrane help dock the vesicles and then zip together to force the membranes to fuse
what does calcium trigger
fusion and exocytosis
what does botulinum toxin work through
SNAP-25 and syntaxin
what happens to membrane potential in EPSP
it gets more positive
what happens to membrane potential in IPSP
it gets more negative
what are excitatory NTs
glutamate, aspartate, and nitric oxide
what are inhibitory NTs
glycine, GABA, serotonin, dopamine
what are excitatory and inhibitory NTs
acetylcholine and norepinephrine
what channels do EPSPs open
cation channels such as Na+ and Ca2+
what channels do IPSPs open
anion channels such as Cl- channels
what is the mechanism of an action potential
if the graded potential caused by the summation of EPSPs and IPSPs reach a threshold potential at the axon hillock, this opens Na+ channels and induce an action potential in the neuronal axon
what is the major excitatory NT in the CNS
glutamate
what is the major inhibitory NT in the CNS
GABA
what does glycine do
inhibitory NT in the spinal cord
what is serotonins precursor
tryptophan
what is acetycholine’s precurosr
choline and acetyl Co A
what is GABA’s precursor
glutamic acid
what is the precursor “cascade” for catecholamines
tyrosine -> DOPA -> dopamine -> norepinephrine -> epinephrine
what are the potential responses to cannabinoids
-increase pleasure
- inhibit pain
- inhibit nausea
- decrease learning/memory
-movement
where are small molecule NT made
in the terminal
where are peptides made
in the cell body
what is the class of AcH
cholinergic
what is the class of DA
dopaminergic
what is the class of NE
noradrenergic
what is the class of Glu
glutamatergic
what is the class of GABA
GABAergic
what is the class of peptide
petidergic
what are the 3 types of receptors
-transmitter gated ion channels
- GPCRs
- enzyme linked receptors
what is another name for transmitter gated ion channels
ionotropic receptors
what is another name for GPCRs
metabotropic receptors
what are examples of transmitter gated ion channels and what do they do
- ion channels such as Na+, K+, Cl-, Ca2+
- depolarize/hyperpolarize the cell
what do GPCRs do
indirectly linked to ion channels (still can open ion channels)
what is an example of an enzyme linked receptor
tyrosine kinase receptor
what happens to the receptor when the NT binds
it changes conformation
what does opening of an ion channel result in
increased concentration of the ion inside of the cell
what is the receptor type for GABA
chloride channel
what does the GABA receptor site also have receptors for
propofol, ethanol, isoflurane, benzodiazepine, barbiturate, opioids
what is another name for acetylcholine ionotropic receptor
nicotinic receptor
what is an antagonist of the acetylcholine ionotropic receptor/ nicotinic receptor
curare
how does a G protein act on its target and what are its targets
diffuses in the membrane to act on its target which may be an ion channel, enzyme, or gene transcription
what is the antagonist of the acetylcholine metabotropic receptor/ muscarinic receptor
atropine
what is another name for the acetylcholine metabotropic receptor
acetylcholine muscarinic receptor
where is the acetylcholine muscarinic receptor found
in organs
which has a greater affinity for the beta1 adrenergic receptor: epinephrine or norepinephrine
Epinephrine
what is the result of epinephrine binding the beta1 adrenergic receptor
ATP -> cAMP -> PKA -> opens Ca2+ channels -> increased heart rate and cardiac contractility
where are nicotinic receptors found
skeletal muscle or nerve or postganglionic neurons
where are muscarinic receptors found and what do they do
in target organs, parasympathetic actions
what are the 3 fates of NT
reuptake, breakdown, diffusion
what happens in reuptake of NT
NT can be returned to axon terminals for reuse or transported into glial cells
what happens in breakdown of NT
enzymes inactivate NTs
what happens in diffusion of NT
NT can diffuse out of synaptic cleft
what does lidocaine do
VGNa channel blocker
what does tetrodotoxin do
VGNa channel blocker
what does caffeine do
increase neuronal excitability
what do SSRIs do
block reuptake
what is an example of SSRI
cocaine
what does ecstasy and amphetamine do in the synaptic cleft
increase release, block reuptake
what does long term potentiation do
form memories by strengthening synapses
how do potentiation of synapses work
-increase the response in the post synaptic neuron either by adding more receptors or phosphorylation of proteins to increase response
-increase the release of NT (glutamate) from presynaptic neuron
