POSTMORTEM STABILITY OF MESSENGER-RNA FOR GLUCOCORTICOID AND MINERALOCORTICOID RECEPTOR IN RODENT BRAIN

The relative postmortem stability of the mRNA's for glucocorticoid (GR ) acid mineralocorticoid (MR) receptor in rodent brain was determined using semi-quantitative in situ hybridization (ISH). Rats were killed by CO2 asphyxiation and their brains removed immediately (0 h) or foll owing 12 h or 24 h delays. Specific hybridization of GR and MR anti-se nse [S-35]RNA-probe to tissue mRNA encoding these receptors was detect ed using film and emulsion autoradiography. The most intense labeling for GR mRNA was in the dentate gyrus followed by the CA1 hippocampal r egion. Lower, but still detectable signal, was apparent over CA3-CA4 p yramidal cell regions. MR mRNA was detected throughout the CA1-4 pyram idal cell fields of the hippocampus acid the granular cells of the den tate gyrus. Film images demonstrated that even in the 24 h postmortem delay group intense specific signal was present in sections hybridized with bath anti-sense GR and MR probes, although there was some diminu tion in signal intensity in cortical areas at this later postmortem de lay. These initial experiments with rat brain demonstrate that the mRN A's for both GR and MR, as detected with ISH, are stable for up to 24 h following death.