Ectopic galanin expression and normal galanin receptor 2 and galanin receptor 3 mRNA levels in the forebrain of galanin transgenic mice
Hohmann, John G.
Steiner, Robert A.
Perez, S. E.
Crawley, Jacqueline N.
Koprich, J. B.
Lipton, J. W.
Mufson, Elliott J.
Counts, S. E.
MetadataShow full item record
The functional interactions of the neuropeptide galanin (GAL) occur through its binding to three G protein-coupled receptor subtypes: galanin receptor (GALR) 1, GALR2 and GALR3. Previously, we demonstrated that GALR1 mRNA expression was increased in the CA1 region of the hippocampus and discrete hypothalamic nuclei in galanin transgenic (GAL-tg) mice. This observation suggested a compensatory adjustment in cognate receptors in the face of chronic GAL exposure. To evaluate the molecular alterations to GALR2 and GALR3 in the forebrain of GAL overexpressing mice, we performed complementary quantitative, real-time PCR (qPCR), in situ hybridization, and immunohistochemistry in select forebrain regions of GAL-tg mice to characterize the neuronal distribution and magnitude of GAL mRNA and peptide expression and the consequences of genetically manipulating the neuropeptide GAL on the expression of GALR2 and GALR3 receptors. We found that GAL-tg mice displayed dramatic increases in GAL mRNA and peptide in the frontal cortex, posterior cortex, hippocampus, septal diagonal band complex, amygdala, piriform cortex, and olfactory bulb. Moreover, there was evidence for ectopic neuronal GAL expression in forebrain limbic regions that mediate cognitive and affective behaviors, including the piriform and entorhinal cortex and amygdala. Interestingly, regional qPCR analysis failed to reveal any changes in GALR2 or GALR3 expression in the GAL-tg mice, suggesting that, contrary to GALR1, these receptor genes are not under ligand-mediated regulatory control. The GAL-tg mouse model may provide a useful tool for the investigation of GAL ligand-receptor relationships and their role in normal cognitive and affective functions as well as in the onset of neurological disease.
Showing items related by title, author, creator and subject.
Differential patterns of Fos induction in the hypothalamus of the rat following central injections of galanin-like peptide and galanin Clifton, Donald K.; Baumgartner, James W.; Steiner, Robert A.; Fraley, Gregory S.; Shimada, Issei (Endocrine Society, 2003-04)Galanin and its newly discovered relative galanin-like peptide (GALP) are neuropeptides that are implicated in the neuroendocrine regulation of body weight and reproduction. GALP has been shown to bind in ...
Distribution and regulation of galanin receptor 1 messenger RNA in the forebrain of wild type and galanin-transgenic mice Hohmann, John G.; Jureus, Anders; Teklemichael, Dawit N.; Matsumoto, Alvin M.; Clifton, Donald K.; Steiner, Robert A. (Endocrine Society, 2003)To learn more about molecular alterations in the brain that occur as a consequence of either the chronic excess or absence of peptide neurotransmitters, we examined the impact of genetically manipulating the ...
Regulation of galanin gene expression in gonadotropin-releasing hormone neurons during the estrous cycle of the rat Clifton, Donald K.; Vrontakis, Maria; Steiner, Robert A.; Marks, Daniel L.; Smith, M. Susan (Endocrine Society, 1993-04)Galanin is colocalized with GnRH in neurons of the hypothalamus and basal forebrain of female rats, and this neuropeptide may play a role in the generation of the midcycle surge of gonadotropin secretion. We ...