What is the major inhibitory neurotransmitter in the brain?

The major inhibitory neurotransmitter in the brain is gamma-aminobutyric acid (GABA). GABA plays a crucial role in regulating neuronal excitability throughout the nervous system. When GABA binds to its receptors, it typically results in the opening of channels that allow negatively charged ions, such as chloride, to enter the neuron or let potassium ions exit. This process hyperpolarizes the neuron, making it less likely to fire an action potential and thus reducing excitatory signals. The balance between excitatory and inhibitory neurotransmitters is essential for maintaining proper brain function and neural homeostasis, and GABA is key to this inhibitory mechanism.

Other neurotransmitters mentioned in the choices serve different roles. Dopamine is primarily involved in reward, motivation, and motor control, while serotonin is linked to mood regulation and various other functions. Glutamate, on the other hand, is the main excitatory neurotransmitter in the brain. Together, all of these neurotransmitters contribute to the complex signaling dynamics within the brain, but when it comes to inhibition, GABA stands out as the primary player.