Question

How may GABA agonists through the GABA A receptors affect the CNS if the [Cl-]i is decreased?

Answer 1

GABAA receptors or GABAR is widely distributed and utilized throughout the CNS and responsible for inhibitory synaptic transmission via chloride channel activation. When GABA agonist binds to GABA A receptor activates chloride ion channels resulting in greater influx of Cl− into the neuron makes it more difficult for the cell to generate a new action potential. GABAA-receptor often increases the conductance accompanied by a membrane hyperpolarization that could rise the firing threshold level and eventually reduces the probability of initiation of action potential resuting in neuronal inhibition. GABA-dependent facilitation of Cl− ion influx facilitates the reduction in membrane resistance. On contrary, under high intracellular Cl−high intracellular Cl−, cellular depolarization accompanied by increased Cl− permeability result in cell excitement and Ca2+ activation via voltage-gated channels.