What is a true statement regarding inhibitory neurotransmitters?

What is a true statement regarding inhibitory neurotransmitters?

• A. They depolarize the cell membrane and increase the chance of an action potential
• B. They open chloride channels that hyperpolarize the cell and decrease action potential likelihood
• C. They open potassium channels that depolarize the membrane
• D. They act only on cation channels

Answer: (B)

The statement highlighting that inhibitory neurotransmitters open chloride channels, leading to hyperpolarization of the cell, accurately describes the mechanism through which these neurotransmitters function. Inhibitory neurotransmitters like gamma-aminobutyric acid (GABA) primarily act by binding to receptors that are part of chloride channels (GABA-A receptors). When these channels open, an influx of chloride ions occurs, resulting in an increase in the negative charge inside the neuron. This hyperpolarization makes it more difficult for the neuron to reach the threshold required for firing an action potential. Therefore, the likelihood of the neuron generating an action potential decreases. The process of hyperpolarization serves to dampen neuronal excitability and is crucial in maintaining a balance between excitation and inhibition within the nervous system, thus preventing excessive neuronal activity, which could lead to seizures or other excitatory states. This is a central aspect of how inhibitory neurotransmitters contribute to overall neural circuit function and stability in the brain.

The statement highlighting that inhibitory neurotransmitters open chloride channels, leading to hyperpolarization of the cell, accurately describes the mechanism through which these neurotransmitters function. Inhibitory neurotransmitters like gamma-aminobutyric acid (GABA) primarily act by binding to receptors that are part of chloride channels (GABA-A receptors). When these channels open, an influx of chloride ions occurs, resulting in an increase in the negative charge inside the neuron. This hyperpolarization makes it more difficult for the neuron to reach the threshold required for firing an action potential. Therefore, the likelihood of the neuron generating an action potential decreases.

The process of hyperpolarization serves to dampen neuronal excitability and is crucial in maintaining a balance between excitation and inhibition within the nervous system, thus preventing excessive neuronal activity, which could lead to seizures or other excitatory states. This is a central aspect of how inhibitory neurotransmitters contribute to overall neural circuit function and stability in the brain.