Chemical Signalling Flashcards
What are the types of neurotransmitter?
amino acids
monoamines
acetylcholine
neuropeptides
What are the types of neurotransmitter?
amino acids
monoamines
acetylcholine
neuropeptides
What are amino acids?
chains of proteins e.g. GABA and glutamate (responsible for fast transmission)
What are examples of monoamines?
dopamine and serotonin
Where are acetylcholine’s synthesised and stored?
they are synthesised in the presynaptic terminal and stored in synaptic vesicles
When are acetylcholine’s released?
when there is a local increase in Ca2+
Where are neuropeptides synthesised and released?
they are synthesised in the cell soma and transported to the terminal where they are stored in secretory granules
When are neuropeptides released?
when there is a global increase in Ca2+
Give an example of a neuropeptide
endorphins
What are amino acids?
chains of proteins e.g. GABA and glutamate (responsible for fast transmission)
What are examples of monoamines?
dopamine and serotonin
Where are acetylcholine’s synthesised and stored?
they are synthesised in the presynaptic terminal and stored in synaptic vesicles
When are acetylcholine’s released?
when there is a local increase in Ca2+
Where are neuropeptides synthesised and released?
they are synthesised in the cell soma and transported to the terminal where they are stored in secretory granules
When are neuropeptides released?
when there is a global increase in Ca2+
Give an example of a neuropeptide
endorphins
What are the criteria for neurotransmitters?
chemically synthesised presynaptically
electrical stimulation leads to the release of a chemical
chemical produces physiological effect
terminate activity
How is glutamate synthesised?
it is synthesised from glucose or glutamine in the nerve terminals
How is glutamate stored?
it is loaded and stored in vesicles by vesicular glutamate transporters
How is glutamate released?
exocytosis
What is neuromodulation?
alteration of the presynaptic cell’s ability to release neurotransmitter or the postsynaptic cell’s ability to respond
What is the reuptake mechanism for glutamate?
excitatory amino acid transporters reuptake glutamate in the plasma membrane of presynaptic cell and surrounding area
What can too much glutamate/too little GABA cause?
hyperexcitability (epilepsy) or excitotoxicity
What is cerebral ischemia?
insufficient blood flow in the brain caused by plaques/tumors
What are some symptoms of ischemia?
weakness
visual impairment
release of glutamate
excitotoxic cell death
What is an agonist?
a drug which can combine with a receptor on a cell to produce a cellular reaction
What is an antagonist?
a drug that reduces or completely block the activity of the agonist, no cellular effect after interacting with a receptor a.k.a. endogenous ligand
What is an excitatory post synaptic potential?
glutamate ionotropic receptors flux Na+ depolarising the postsynaptic neuron
What is an inhibitory post synaptic potential?
GABA ionotropic receptors flux Cl- hyper polarising the postsynaptic neuron
What happens at an AMPA receptor?
an ionotropic receptor
the binding of glutamate leads to the opening of a Na+ channel and hence depolarisation
has slight K+ permeability
a fast opening channel
What are the features of an NMDA receptor?
an ionotropic receptor voltage dependent blockade permeable to Na+, K+, Ca2+ slow opening channel requires glutamate and glycine (cofactor) to open the gate
What can be caused by the dysregulation of NMDA?
Schizophrenia symptoms