Quantitative analysis of gene expression in organotypic slice-explant cultures by particle-mediated gene transfer

Biolistics, also known as particle-mediated gene transfer, has been used as an effective method to transfect primary neurons in cultured slices when all other methods have proven unsuccessful. Most of these uses have provided qualitative or semi-quantitative data based on visual assays such as immunohistochemistry. In this paper, we describe a quantitative method of biolistics to analyze gene expression in organotypic cultures of hippocampus and hypothalamus. The method involves co-transfection of the experimental promoters and standard (cytomegalovirus or Rous sarcoma virus) promoters coupled to different reporters (luciferase or β-galactosidase), with the standard promoter-reporter construct used to 'normalize' the experimental data. Examples and validations of this technique with various cell specific promoters are given: for example, astrocyte-specific and neuron-specific (α- tubulin and N-type calcium channel α-1B gene) promoters and various tissues (Neuro 2A cells and hippocampal and hypothalamic organotypic slice- explants). An analysis of deletion constructs of the α 1B calcium channel subunit gene is described. This method should provide a new opportunity for the analysis of gene expression in diverse neuronal phenotypes.