SUBCELLULAR-DISTRIBUTION OF RIBOSOMAL-RNA AND POLY(A) RNA IN HIPPOCAMPAL-NEURONS IN CULTURE

In situ hybridization was used to assess the subcellular distribution of rRNA and poly(A) RNA in hippocampal neurons maintained in culture. Labeling produced with S-35-labeled probes to either rRNA or poly(A) w as heaviest over the cell body with lighter, patchy labeling of proxim al dendrites. In contrast, H-3-labeled probes labeled dendrites throug hout their length, and the ratio of dendritic to cell body labeling wa s higher with H-3-labeled probes. There was no detectable labeling of axons of mature neurons with either probe. The pattern of hybridizatio n produced by S-35-labeled oligonucleotide probes to rRNA varied depen ding on the concentration of the oligonucleotide. These studies provid e the first detailed study of the subcellular distribution of rRNA and poly(A) RNA in neurons, and highlight technical issues to consider wh en evaluating results of hybridizations carried out with S-35- and H-3 -labeled probes on cells in culture.