ALTERATION OF GABA(A) RECEPTOR FUNCTION FOLLOWING GENE-TRANSFER OF THE CLC-2 CHLORIDE CHANNEL

The effect of GABA(A) receptor activation varies from inhibition to ex citation depending on the state of the transmembrane anionic concentra tion gradient (del(anion)). del(anion) was genetically altered in cult ured dorsal root ganglion neurons via adenoviral vector-mediated expre ssion of ClC-2, a Cl- channel postulated to regulate the Cl- concentra tion in neurons in which GABA(A) receptor activation is predominantly inhibitory. ClC-2 expression was verified by the presence of the appro priate mRNA, protein, and membrane conductance. ClC-2 expression resul ted in a large negative shift in the Cl- equilibrium potential (E(Cl)) that attenuated the GABA-mediated membrane depolarization and prevent ed GABA(A) receptor-mediated action potentials. These results establis h that gene transfer of transmembrane ion channels to neurons can be u sed to demonstrate their physiological function, and that del(anion) c an be genetically manipulated to alter the function of neuronal GABA(A ) receptors in situ.