GABA Flashcards
what does GABA stand for
Gamma-aminobutyric acid
what is GABA
inhibitory neurotransmitter that plays crucial role in the central nervous system
GABAs inhibition of neural activity
when GABA binds to receptor on neuron, typically opens chloride channels allowing chloride ions to enter the neuron.
influx of negatively charged ions makes the inside of the neuron more negative and less likely to generate an action potential,
thus inhibiting the neurons activity.
this is all mainly GABA- A
GABAs receptors
GABA-A and GABA- B
what type of receptor is GABA- A
ligand gated ion channel
what type of receptor is GABA-B
G-protein coupled
what is the anxiolytic effect
anxiety reducing effect (benzodiazepines) act on GABA-A receptors. these drugs enhance the inhibitory effects of GABA leading to calming
what is GABA made from
Glutamate
what are some reasons for insufficient GABA levels
neurological disorders like epilepsy
not enough glutamate
genetic factors
brain trauma
list some symptoms of insufficient GABA
anxiety, stress
alcoholism
hypertension
insomnia
chronic pain
what are some things that increase GABA levels
magnesium
L-thanine
L-arginine
B
what are symptoms for excess GABA
low blood pressure
Gastric distress
constipation
muscle weakness
shortness of breath
nausea
how do you reduce GABA
stimulants like caffeine
GABA-A antagonists
what are GABA-A modulatory sites
sites where various substances can bind and modulate receptor activity
e.g. benzodiazepine-binding site
GABA-B structure
heterodimer composed of 2 subunits, GABA-B1 and GABA-B2
what is GABA-B1 responsible for
ligand binding
what is GABA-B2 responsible for
receptor signalling
how many transmembrane domains for both subunits have
7
what happens when GABA binds to GABA-B
intracellular domains of GABA-B1 and GABA-B2 interact with G proteins, specifically Ga and GBY subunits.
this interaction triggers downstream signalling cascade
what do GABA-B receptors signal through
inhibitory G proteins, leading to the inhibition of adenylate cyclase and a subsequent decrease in cAMP levels.
where are GABA-B receptors located
presynaptically, where their activation inhibits the release of neurotransmitters including GABA itself.
GABA-B modulation of neuronal excitability
GABA-B receptors modulate excitability by influencing ion channels such as potassium and calcium.
resulting hyperpolarisation or inhibition of calcium influx contributes to the overall inhibitory effect
