Question

The inhibitory neurotransmitters of the CNS, GABA and glycine, act by opening ________ channels.

A) only Na+
B) only Cl-
C) only K+
D) only Ca2+
E) Na+ and K+

Answer 1

The inhibitory neurotransmitters GABA and glycine act by opening chloride (Cl-) channels, causing hyperpolarization of the membrane and decreasing cell excitability. GABAA receptors are ionotropic chloride channels, while GABAB receptors open potassium (K+) channels.

Step-by-step explanation:

The inhibitory neurotransmitters of the CNS, GABA and glycine, act by opening chloride (Cl-) channels. GABAA receptors are ionotropic chloride channels, and the activation of these receptors allows the influx of chloride ions, hyperpolarizing the membrane and decreasing the excitability of the cell. GABAB receptors, on the other hand, trigger the opening of potassium (K+) channels, resulting in hyperpolarization of the postsynaptic neuron.