[Campbell Biology P.1130] Which of the following statements correctly describes inhibitory ne... | Practice Question

Which of the following statements correctly describes inhibitory neurotransmitters or related drug actions based on the provided text?

  • A: Glutamate is a major inhibitory neurotransmitter in the CNS, increasing Cl- permeability upon binding.
  • B: Glycine acts at inhibitory synapses and increases Na+ influx into postsynaptic cells, leading to an IPSP.
  • C: GABA (gamma-aminobutyric acid) is the neurotransmitter at most inhibitory synapses, and its binding increases membrane permeability to Cl-, resulting in an IPSP.
  • D: Diazepam reduces anxiety by blocking GABA receptors, thereby reducing neuronal inhibition.

Explanation

The text explicitly states that GABA is the neurotransmitter at most inhibitory synapses and that 'Binding of GABA to receptors in postsynaptic cells increases membrane permeability to Cl-, resulting in an IPSP.' It also notes that diazepam reduces anxiety by 'binding to a site on a GABA receptor, increasing the response to GABA.'