Question

Which of the following statements about GABA receptors is not true?

(a) They are located on postsynaptic membranes.
(b) They are ligand-gated channels.
(c) They inhibit synaptic signaling.
(d) They promote neuronal uptake of Na+.

Answer 1

The inaccurate statement regarding GABA receptors is that they promote neuronal uptake of Na+, which is untrue since GABA receptors usually allow the influx of Cl- ions leading to hyperpolarization.

Step-by-step explanation:

The statement about GABA receptors that is not true is (d) They promote neuronal uptake of Na+. GABA receptors are known for their role in inhibitory neurotransmission. The opening of GABAA receptors—which are ionotropic—results in an influx of chloride ions (Cl−), leading to the hyperpolarization of the postsynaptic neuron and thereby inhibiting action potentials. This mechanism does not involve the uptake of Na+. In fact, the inhibition of neuronal excitability via GABA receptors is crucial for the regulation of brain activity and prevention of synaptic overexcitation. Instead, the activation of GABA receptors allows the influx of chloride ions, which hyperpolarizes the membrane and decreases the excitability of the cell.