National Certified Addiction Counselor, Level 2 (NCAC II) Practice Exam Exam

What is the main function of inhibitory neurotransmitters in the brain?

1. To enhance the firing of neurons

2. To decrease neuronal excitability

3. To facilitate learning and memory

4. To regulate heart rate

The correct answer is: To decrease neuronal excitability

Inhibitory neurotransmitters play a crucial role in maintaining the balance of neural activity in the brain by decreasing neuronal excitability. They achieve this by binding to specific receptors on the postsynaptic neuron, resulting in hyperpolarization. This makes it more difficult for the neuron to reach the threshold for firing an action potential, effectively dampening neuronal transmission. This function is essential for preventing over-excitation in neural networks, which is important in a variety of physiological and cognitive processes. When inhibitory neurotransmitters, such as gamma-aminobutyric acid (GABA), act on neurons, they help to regulate brain activity, promote calmness, and reduce anxiety. This balancing act is vital for maintaining overall neurological health and function.