Postmortem stability of dopamine D1 receptor mRNA and D1 receptors.

The effects of postmortem interval on dopamine D1 mRNA and D1 receptors were assessed in rat striatum under conditions simulating the handling of human brain tissue at 0, 6, 12, and 24 h postmortem. The amount of D1 mRNA was measured by both in situ hybridization film and emulsion autoradiography with [35S]dATP-labeled oligonucleotide probes. D1 receptor density was determined by autoradiography with [125I]SCH 23982. Neither the total amount of D1 mRNA in the striatum nor the frequency distribution of striatal cells expressing D1 mRNA varied with the postmortem interval. There was a modest but significant decrease (ca. 10%) in D1 receptors over the 24 h postmortem interval; this decrease occurred within the first 6 h postmortem, with no further decreases up to 24 h postmortem. These findings suggest that the effects of postmortem interval on D1 mRNA and receptors are minimal and should not limit an examination of possible alterations in dopamine D1 receptor mRNA and D1 receptors in the postmortem brains of humans with neuropsychiatric disease.