Neurotransmitters Flashcards
What are the types of neurotransmitters
amino acids, amines, neuropetides
What are the characteristics of amino acid and amine neurotransmitters
small, bind to ligand gated ion channels and GPCRs, in synaptic vesicles
What are the characteristics of peptide neurotransmitters
large, activate GPCRs, in secretory granules
What is Dale’s principle
a neuron only has one neurotransmitter
Is Dale’s principle always valid?
No
What is gluatmate
most common excitatory neurotransmitter
Where is glutamate synthesised
neurons
TRUE or FALSE - Glutamate CANNOT pass the BBB
True
What receptors does glutamate interact with?
ionotropic NMDA, AMPA and kainate receptors
What do NMDA, AMPA and kainate receptors allow?
influx of Na+ into post-synaptic neuron
What is the effect of Na+ influx into the post-synaptic neuron
depolarisation - more likely to fire action potential
What supporting cell can take up gluatmate
glia
What do AMPA receptors mediate
fast excitatory transmission
What receptors often co-exist
NMDA and AMPA
Which receptors have a voltage dependent Mg2+ block
NMDA
Which receptor needs to be indirectly activate by another transmitter
NMDA
What is NMDA permeable to
Ca2+, K+, Na+
What is the effect of glutamate binding to AMPA receptors
Na+ and K+ currents making an EPSP
What is the precursor to GABA
glutamate
What does synthesis of GABA require ?
enzyme glutamatic acid decarboxylase
How is action of GABA terminated
selective uptake into presynaptic terminals
What is GABA
most common inhibitory neurotransmitter in CNS
What does GABA produce
IPSPs via GABA gated chloride channels
Where is GABA found
CNS, cortex, striatum
What is the effect of too much GABA
coma
What is the effect of chloride influx into the cell
suppresses neuron from firing
What channels can GABA inhibit
calcium channels
What chemicals can modulate the effect of GABA
ethanol, barbiturate, benzodiazepine
What are barbiturates
sedatives, anti-convulsants
Where are opioids formed
Rough ER
What are opioids packaged into
secretory granules
Where are opioid receptors concentrated
nociceptive areas
What are the main types of opioid receptors
mu, kappa, sigma
What can opioid receptors be coupled to
inhibitory G-proteins
What do opioid receptors act as
modulators
What is the function of opioid receptors
decrease excitability of the cell
What are the therapeutic uses of opioids
analgesia, intestinal disorders, anti-tussive
Where do neurons arise
central core of brain - brainstem