Recombinant GABA(c) receptors expressed in rat hippocampal neurons after infection with an adenovirus containing the human rho 1 subunit

1. A recombinant adenovirus was generated with the human rho1 GABA(C) recep tor subunit (adeno-rho). Patch-clamp and antibody staining were employed to confirm functional expression of recombinant rho1 receptors after infectio n of human embryonic kidney cells (HEK293 cell line), human embryonic retin al cells (911 cell line), dissociated rat hippocampal neurons and cultured rat hippocampal slices. 2. Standard whole-cell recording and Western blot analysis using rho1 GABA( C) receptor antibodies revealed that recombinant rho1 receptors were expres sed in HEK293 and 911 cells after adeno-rho infection and exhibited propert ies similar to those of rho1 receptors after standard transfection. 3. Cultured rat hippocampal neurons (postnatal day (P)3-P5) did not show a native GABA(C)-like current. After adeno-rho infection, however, a GABA(C)- like current appeared in 70-90% of the neurons. 4. Five days after infection, expression of GABA(C) receptors in hippocampa l neurons significantly decreased native GABA(A) receptor currents from 120 0 +/- 300 to 150 +/- 70 pA (n = 10). The native glutamate-activated current was unchanged. 5. Hippocampal slices (P8) did not show a native GABA(C)-like current, alth ough recombinant rho1 receptors could be expressed in cultured hippocampal slices after adeno-rho infection. 6. These data indicate that an adenovirus can be used to express recombinan t GABA(C) receptors in hippocampal neurons. This finding could represent an important step towards the gene therapy of CNS receptor-related diseases.