Rapid ReportReduced anticipatory locomotor responses to scheduled meals in ghrelin receptor deficient mice
Section snippets
Animals
Mice with targeted mutations to the ghrelin receptor gene (GHSR KO) and their wild type (WT) littermates were bred at the Carleton University Neuroscience Institute animal facilities. Mice originated from heterozygous breeding pairs obtained from Regeneron Pharmaceuticals in Tarrytown, NY, USA. These mice were generated using a mixed C57bl/J6 and DBA strain as background. Additional mice (C57bl/J6) were obtained from Jackson Laboratories in Bar Harbor, ME, USA. All animals had free access to
Mice show elevated ghrelin concentrations in anticipation of a scheduled meal
As expected, food restricted C57BL/J6 mice adjusted their feeding patterns so as to consume almost all of their normal 24 h food intake during the restricted access period (Interaction effect F(1,14)=4.8, P<0.05; see supplemental Fig. 1, panel A). These animals were capable of doing this within a period of 7 days after the start of the restricted feeding schedule, and consumed more than control animals during the 4 h access period (F(1,14)=198.88, P<0.05; see panel B). Analyses of plasma
Discussion
The coordination of physiological functions and behavioral responses with environmental predictors of food is a critical adaptive feature (Silver and Lesauter, 2008). Environmental cues signaling the proximity of food such as time of day, or a particular place influence a number of peripheral and central mechanisms to generate the behavioral repertoire (i.e. arousal, foraging, risk taking, hoarding, and food consumption) that is necessary to secure the needed nourishment. In this study we
Acknowledgments
This project was funded by grants from the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canadian Funds for innovation (CFI) awarded to A.A., and from National Institute of Health (NIH) grant to T.L.H. (DK-060711).
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2022, PsychoneuroendocrinologyCitation Excerpt :It is possible that SuM neurons are recruited by neurons that sense the elevation of plasma ghrelin. Alternatively, the activation of SuM neurons in calorie restricted mice may result from other some aspects of protocol that have also been linked to GHSR signaling, such as the severe energy deficit itself (Goldstein et al., 2011), stress (Cabral et al., 2012, 2016) or anticipatory responses to scheduled meals or related cues (Blum et al., 2009). The previously mentioned study in rats also found that satiated animals conditioned to daily receive an energy‐dense food for seven days display an increase of c‐Fos expression in the SuM after consuming the palatable food (Le May et al., 2019).
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These authors contributed equally to this work.