POSTMORTEM STABILITY OF DOPAMINE D1 RECEPTOR MESSENGER-RNA AND D1 RECEPTORS

The effects of postmortem interval on dopamine D1 mRNA and D1 receptor s were assessed in rat striatum under conditions simulating the handli ng 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 emulsio n autoradiography with [S-35]dATP-labeled oligonucleotide probes. D1 r eceptor density was determined by autoradiography with [I-125]SCH 2308 2. Neither the total amount of D1 mRNA in the striatum nor the frequen cy distribution of striatal cells expressing D1 mRNA varied with the p ostmortem interval. There was a modest but significant decrease (ca. 1 0%) in D1 receptors over the 24 h postmortem interval; this decrease o ccurred within the first 6 h postmortem, with no further decreases up to 24 h postmortem. These findings suggest that the effects of postmor tem interval on D1 mRNA and receptors are minimal and should not limit an examination of possible alterations in dopamine D1 receptor mRNA a nd D1 receptors in the postmortem brains of humans with neuropsychiatr ic disease.