| First Author | Bäckberg M | Year | 2004 |
| Journal | Brain Res Mol Brain Res | Volume | 125 |
| Issue | 1-2 | Pages | 129-39 |
| PubMed ID | 15193430 | Mgi Jnum | J:115482 |
| Mgi Id | MGI:3691761 | Doi | 10.1016/j.molbrainres.2004.03.012 |
| Citation | Backberg M, et al. (2004) Down-regulated expression of agouti-related protein (AGRP) mRNA in the hypothalamic arcuate nucleus of hyperphagic and obese tub/tub mice. Brain Res Mol Brain Res 125(1-2):129-39 |
| abstractText | A mutation in the mouse tub gene causes a phenotype characterized by maturity-onset obesity, blindness and deafness. The role of the intact tubby protein and the pathogenesis resulting in the phenotype of tub/tub mice remain largely unknown. In this study, we have investigated whether obese tub/tub mice exhibit altered expression levels for agouti-related protein (AGRP) or glutamic acid decarboxylase-65 (GAD65) in body weight-regulating neurons of the hypothalamic arcuate nucleus. In situ hybridization revealed that AGRP, but not GAD65 mRNA levels, were significantly lower in obese tub/tub mice as compared to tub/+ mice. The lower levels of AGRP mRNA in the arcuate nucleus of tub/tub mice were paralleled by lower fluorescence intensity and numbers of AGRP- and neuropeptide Y (NPY)-immunoreactive (ir) nerve fibers and terminals in the arcuate, ventromedial, dorsomedial hypothalamic nuclei and perifornical and lateral hypothalamic areas. No obvious differences in GAD65-ir nerve fibers and terminals could be detected. Measurements of daily food intake revealed that tub/tub mice displayed progressively higher food consumption as compared to lean tub/+ littermates over a 15-day observation period. When moved to an unfamiliar environment, e.g. a novel cage, daily food intake was initially lower in tub/tub mice than in tub/+ mice suggesting that tub/tub mice may be more sensitive to psychogenic stress. The results together show that tub/tub mice are hyperphagic and exhibit, within the hypothalamic arcuate nucleus, a depressed expression of neuropeptides involved in the regulation of feeding behavior. |
