GABA AND THE GABA(A) RECEPTOR

The neurotransmitter gamma-aminobutyric acid (GABA) inhibits the activ ity of signal-receiving neurons by interacting with the GABAA receptor on these cells. The GABAA receptor is a channel-forming protein that allows the passage of chloride ions into the cells. Excessive GABAA ac tivation may play a role in mediating the sedative effects of alcohol and other sedating and anesthetic agents. For example, alcohol enhance s the GABAA-mediated chloride flow into cells and may thereby enhance neuronal inhibition. Alcohol's effects on the GABAA-receptor function likely involve other molecules (e,g, other neurotransmitters and prote ins that add phosphate groups to the receptor [i.e., protein kinases]) . Several experimental approaches also have suggested that changes in GABA(A)-receptor function contribute to the tolerance to and dependenc e on alcohol. Finally, individual differences in the GABA system may p lay a role in determining a person's susceptibility to developing alco hol dependence.