Intron-specific neuropeptide probes.

Measurements of changes in pre-mRNA levels by intron-specific probes are generally accepted as more closely reflecting changes in gene transcription rates than are measurements of mRNA levels by exonic probes. This is, in part, because the pre-mRNAs, which include the primary transcript and various splicing intermediates located in the nucleus (also referred to as heteronuclear RNAs, or hnRNAs), are processed rapidly (with half-lives <60 min) as compared to neuropeptide mRNAs, which are then transferred to the cytoplasm and which have much longer half-lives (often over days). In this chapter, we describe the use of exon-and intron-specific probes to evaluate oxytocin (OT) and vasopressin (VP) neuropeptide gene expression by analyses of their mRNAs and hnRNAs by quantitative in situ hybridization (qISH) and also by using specific PCR primers in quantitative, real-time PCR (qPCR) procedures.