[Quantitative assay of 5-HT(1A) serotonin receptor gene expression in the brain]

Serotonin 5-HT(1A) receptors participate in the regulation of many kinds of behavior and are implicated in the mechanism of action of anxiolitics and antidepressants. The investigation of 5-HT(1A) receptor gene expression is complicated by low concentration of the receptor mRNA. Our method of quantification of the receptor gene expression in brain structures includes estimation of the concentration of genomic DNA contamination, the number of cDNA copies of glyceraldehyde-3-phosphate dehydrogenase (GAPDH)--one of the "housekeeping genes", and the number of cDNA copies of 5-HT(1A) receptor in the sample. To evaluate the number of cDNA copies of the receptor and GAPDH, the fluorescence intensity of PCR-product was calibrated using genomic DNA-standard of a known concentration. The intensity of 5-HT(1A) receptor gene expression was corrected by genomic DNA contamination and was evaluated as a number of copies of 5-HT(1A) receptor cDNA per 100 copies of GAPDH cDNA. Using this method an increase of 5-HT(1A) receptor gene expression in the frontal cortex and amygdala in monoamine oxidase A knockout mice was shown.