title: Spontaneous brain processing of the mammary pheromone in rabbit neonates prior to milk intake.
abstract: Chemical signals play a critical role in interindividual communication, including mother-young relationships. Detecting odor cues released by the mammary area is vital to the newborn's survival. European rabbit females secret a mammary pheromone (MP) in their milk, which releases sucking-related orocephalic movements in newborns. Pups spontaneously display these typical movements at birth, independently of any perinatal learning. Our previous Fos mapping study (Charra et al., 2012) performed in 4-day-old rabbits showed that the MP activated a network of brain regions involved in osmoregulation, odor processing and arousal in comparison with a control odor. However, at this age, the predisposed appetitive value of the MP might be reinforced by previous milk intake. Here, the brain activation induced by the MP was examined by using Fos immunocytochemistry and compared to a neutral control odor in just born pups (day 0) that did not experienced milk intake. Compared to the control odor, the MP induced an increased Fos expression in the posterior piriform cortex. In the lateral hypothalamus, Fos immunostaining was combined with orexin detection since this peptide is involved in arousal/food-seeking behavior. The number of double-labeled cells was not different between MP and control odor stimulations but the total number of Fos stained cells was increased after MP exposure. Our results indicate that the MP does not activate the same regions in 0- vs. 4-day-old pups. This difference between the two ages may reflect a changing biological value of the MP in addition to its constant predisposed releasing value.
authors.affiliation: Centre des Sciences du Goût et de l'Alimentation (Research Center for Taste and Feeding Behavior), UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, Dijon, France.
authors.forename: Nanette Y
authors.initials: NY
authors.lastname: Schneider
authors.affiliation: Centre des Sciences du Goût et de l'Alimentation (Research Center for Taste and Feeding Behavior), UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, Dijon, France.
authors.forename: Coralie
authors.initials: C
authors.lastname: Piccin
authors.affiliation: Centre des Sciences du Goût et de l'Alimentation (Research Center for Taste and Feeding Behavior), UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, Dijon, France. Electronic address: frederique.datiche@u-bourgogne.fr.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Datiche
authors.affiliation: Centre de Recherche en Neurosciences de Lyon (Lyon Neuroscience Research Center) INSERM U1028/CNRS UMR 5292/Université Claude Bernard Lyon 1, Lyon, France. Electronic address: gerard.coureaud@cnrs.fr.
authors.forename: Gérard
authors.initials: G
authors.lastname: Coureaud
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000378:metabolism*; D004435:Eating; D007858:Learning; D008892:Milk; D009474:Neurons / Q000378:metabolism; D009812:Odorants; D009833:Olfactory Pathways / Q000378:metabolism*; D000068797:Orexins / Q000378:metabolism; D010675:Pheromones / Q000378:metabolism*; D011817:Rabbits
chemical_list: D000068797:Orexins; D010675:Pheromones
keywords: C-fos; Lateral hypothalamus; Mammary pheromone; Newborn rabbit; Orexin; Posterior piriform cortex