Gamma-aminobutyric acid, or GABA, is the primary inhibitory neurotransmitter in the central nervous system, and its receptors, known as GABA receptors, play crucial roles in regulating neuronal activity. There are two main types of GABA receptors: GABA-A receptors and GABA-B receptors, each with distinct mechanisms of action. 1. GABA-A Receptors: GABA-A receptors are ligand-gated ion channels, meaning they allow the passage of ions when activated by a neurotransmitter—in this case, GABA. When GABA binds to the GABA-A receptor, the receptor undergoes a conformational change that opens a channel, allowing chloride ions (Cl-) to flow into the neuron. This influx of negative ions hyperpolarizes the neuron, making it more resistant to depolarization and less likely to generate an action potential. In simpler terms, the binding of GABA to GABA-A receptors enhances the inhibitory effect on the neuron, preventing excessive neuronal firing and maintaining a balance in neural activity. 2. GA...