A study of non-isotopic in situ hybridization histochemistry on postmortem changes in vasopressin mRNA in rat brain

Rat models which stimulated various postmortem conditions were used to determine postmortem changes in the vasopressin mRNA content of the brain. In situ hybridization histochemistry experiments using biotinylated oligonucleotide probes revealed that vasopressin mRNA could be detected in the rat hypothalamic nuclei, even though the rats had been killed and left for 8 h postmortem at room temperature and the brains were then fixed by immersion in 4% paraformaldehyde instead of by transcardial perfusion. However, these signals were greatly reduced in the nuclei if the brains were removed after a 24-h delay. These results suggest that gene expression study of neuropeptides at the cellular level can be performed on postmortem human brains after a short postmortem delay.