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Recent evidence suggests a role for corticotropin-releasing factor (CRF) in the regulation of pair bonding in prairie voles. We have previously shown that monogamous and non-monogamous vole species have dramatically different distributions of CRF receptor type 1 (CRF 1 ) and CRF receptor type 2 (CRF 2 ) in the brain, and that CRF 1 and CRF 2 receptor densities in the nucleus accumbens (NAcc) are correlated with social organization. Monogamous prairie and pine voles have significantly lower levels of CRF receptor type 1 (CRF 1 ), and significantly higher levels of type 2 (CRF 2 ) binding, in NAcc than non-monogamous meadow and montane voles. Here, we report that microinjections of CRF directly into the NAcc accelerate partner preference formation in male prairie voles. Control injections of CSF into NAcc, and CRF into caudate-putamen, did not facilitate partner preference. Likewise, CRF injections into NAcc of non-monogamous meadow voles also did not facilitate partner preference. In prairie voles, this CRF-facilitation effect was blocked by co-injection of either CRF 1 or CRF 2 receptor antagonists into NAcc. Immunocytochemical staining for CRF and Urocortin-1 (Ucn-1), two endogenous ligands for CRF 1 or CRF 2 receptors in the brain, revealed that CRF, but not Ucn-1, immunoreactive fibers were present in NAcc. This supports the hypothesis that local CRF release into NAcc could activate CRF 1 or CRF 2 receptors in the region. Taken together, our results reveal a novel role for accumbal CRF systems in social behavior.Keywords nucleus accumbens; attachment; CRF1; CRF2; corticotropin-releasing factor; corticotrophinreleasing hormone; vole; neuropeptide receptors; pair bond; social behavior; monogamy; species differencesThe corticotropin-releasing factor (CRF) system is involved in the neurobiology underlying stress and anxiety, but much less is known about its role in social behavior. Microtine rodents exhibit diverse social organizations and thus offer an excellent comparative approach in the study of the neurobiology of social behavior (Young and Wang, 2004 Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. (Getz, Carter, and Gavish, 1981;Salo, Shapiro, and Dewsbury, 1993). In contrast, closely-related meadow (Microtus pennsylvanicus) and montane voles (Microtus montanus) are promiscuous and solitary (Gruder-Adams and Getz, 1985;Shapiro and Dewsbury, 1990). Past research has revealed that the brain distribution of neuropeptide receptors for oxytocin and vasopressin appears to be responsible for the species differences in social organization (Insel and Shapiro, 1992;In...

Bacteria play an important role in the decomposition and cycling of a variety of compounds in freshwater aquatic environments, particularly nutrient-rich eutrophic lakes. A unique Chinese eutrophic lake - Dianchi - was selected for study because it has two separate and distinct basins, Caohai with higher organic carbon levels and Waihai with lower organic carbon levels. Sediment bacterial communities were studied in the two basins using samples collected in each season from June 2010 to March 2011. Barcoded pyrosequencing based on the 16 S rRNA gene found that certain common phyla, Proteobacteria, Bacteroidetes, Firmicutes and Chloroflexi, were dominant in the sediments from both basins. However, from the class to genus level, the dominant bacterial groups found in the sediments were distinct between the two basins. Correlation analysis revealed that, among the environmental parameters examined, total organic carbon (TOC) accounted for the greatest proportion of variability in bacterial community. Interestingly, study results suggest that increasing allochthonous organic carbon could enhance bacterial diversity and biomass in the sediment. In addition, analysis of function genes (amoA and nosZ) demonstrated that ammonia-oxidizing bacteria (AOB) were dominant in sediments, with 99% belonging to Nitrosomonas. Denitrifying bacteria were comparatively diverse and were associated with some cultivatable bacteria.