Which of the following statements about GABA receptors is true?

The statement that GABA receptors decrease neural excitability is accurate. GABA, or gamma-aminobutyric acid, is the primary inhibitory neurotransmitter in the central nervous system. When GABA binds to its receptors, it typically causes an influx of chloride ions into the neuron, leading to hyperpolarization. This process makes the neuron less likely to fire an action potential, thereby reducing overall neural excitability and promoting a calming effect on brain activity. This function is crucial in maintaining the balance between excitation and inhibition in the nervous system, which is essential for normal functioning and preventing conditions such as anxiety or seizures.

In contrast, the other statements are not true as GABA receptors exhibit a diverse range of subunit arrangements that contribute to their functional variability, they do not exclusively control pleasure responses but are involved in a variety of functions including anxiety regulation, and they play a significant role in mediating anxiety levels rather than being indifferent to them.