LOCALIZED GENE-TRANSFER INTO ORGANOTYPIC HIPPOCAMPAL SLICE CULTURES AND ACUTE HIPPOCAMPAL SLICES

Viral vectors derived from herpes simplex virus, type-1 (HSV), can tra nsfer and express genes into fully differentiated, post-mitotic neuron s. These vectors also transduce cells effectively in organotypic hippo campal slice cultures. Nanoliter quantities of a virus stock of HSVlac , an HSV vector that directs expression of E. coli beta-galactosidase (beta-gal), were microapplied into stratum pyramidale or stratum granu losum of slice cultures. Twenty-four hours later, a cluster of transdu ced cells expressing beta-gal was observed at the microapplication sit e. Gene transfer by microapplication was both effective and rapid. The titer of the HSVlac stocks was determined on NIH3T3 cells. Eighty-thr ee percent of the beta-gal forming units successfully transduced beta- gal after microapplication to slice cultures. beta-Gal expression was detected as rapidly as 4 h after transduction into cultures of fibrobl asts or hippocampal slices. The rapid expression of beta-gal by HSVlac allowed efficient transduction of acute hippocampal slices. Many gene s have been transduced and expressed using HSV vectors; therefore, thi s microapplication method can be applied to many neurobiological quest ions.