Peroxisome proliferator-activated receptor gamma (PPARy) is a ligand-activated transcription factor that was originally identified as a regulator of peroxisome proliferation and adipocyte differentiation. Emerging evidence suggests that functional PPARy signaling also occurs within the hypothalamus. However, the exact distribution and identities of PPARy-expressing hypothalamic cells remains under debate. The present study systematically mapped PPARy mRNA expression in the adult mouse brain using in situ hybridization histochemistry. PPARy mRNA was found to be expressed at high levels outside the hypothalamus including the neocortex, the olfactory bulb, the organ of the vasculosum of the lamina terminalis (VOLT), and the subfornical organ. Within the hypothalamus, PPARy was present at moderate levels in the suprachiasmatic nucleus (SCh) and the ependymal of the 3rd ventricle. In all examined feeding-related hypothalamic nuclei, PPARy was expressed at very low levels that were close to the limit of detection. Using qPCR techniques, we demonstrated that PPARy mRNA expression was upregulated in the SCh in response to fasting. Double in situ hybridization further demonstrated that PPARy was primarily expressed in neurons rather than glia. Collectively, our observations provide a comprehensive map of PPARy distribution in the intact adult mouse hypothalamus.
- Confocal laser scanning microscopy
- In situ hybridization
- Mouse brain
- Transcription factors
ASJC Scopus subject areas
- Neuroscience (miscellaneous)
- Cellular and Molecular Neuroscience