A vaccinia virus vector for efficiently introducing into hippocampal slices.

We have developed a novel technique using vaccinia virus for highly efficient introduction of foreign genes into viable cells of brain slice to study function of nervous system. Hippocampal slices of adult guinea pigs were infected with a vaccinia virus carrying a gene for beta-galactosidase (beta-gal) as a reporter gene. Expression of beta-galactosidase was first detected after 5 hours and reached maximum after 16 to 24 hours. Light microscopic observation revealed that beta-galactosidase was expressed uniformly in the CA1-CA3 pyramidal cell layer, granule cell layer of dentate gyrus and glial cells. Serial sections of infected slices showed that cells were uniformly infected throughout the thickness of the slice. Thus, the vaccinia virus system provides a convenient gene transfer tool for studying brain function in cultured slice system.