Patterns and labelling characteristics in neuronal and glial RNA.

Abstract

Abstract— Rabbit cortex slices were incubated in a medium containing [3H]‐uridine for various periods of time. Following incubation, neuronal and glial cell fractions were prepared on a discontinuous Ficoll‐sucrose gradient. RNA was extracted from neurons and glia with a tris‐sodium dodecyl sulphate‐phenol solution and fractionated on a composite agarose‐polyacrylamide gel. The stained gel showed major bands corresponding to 28 s, 18 s, 5 s and 4 s fractions and additional minor bands at the position of 24 s, 21 s and 13 s. Neuronal and glial RNA had the same general RNA pattern but the 5 s fraction was more pronounced in neuronal RNA and 4 s more pronounced in glial RNA. After 30 min labelling both neuronal and glial RNA had maximum activities in fractions higher than 28 s with a peak corresponding to 45 s. In the lower mol. wt. region the labelling was essentially poly‐disperse. With increasing incubation time, peaks corresponding to 38 s and 32 s appeared as well as to ribosomal and soluble fractions. Incorporation of activity into total RNA expressed as d.p.m/μg of nucleic acids, showed similar labelling in neurons and glia after 30 and 60 min and a 3‐4 times higher incorporation into neuronal RNA after 180 min. The possible implications of these results are discussed.