title: Chemical Identification of "Maternal Signature Odors" in Rat.
abstract: Newborn altricial mammals need just after birth to locate their mother's nipples for suckling. In this precocious behavior, including for the human baby, maternal odor via the olfactory process plays a major role. Maternal odor emitted by lactating females or by amniotic fluid (AF) attracts pups, but the chemical identity of this attractant has not yet been elucidated. Here, using behavioral tests and gas chromatography coupled with mass spectrometry (GC-MS) techniques, we show that AF extracts from rat pregnant female, nipples, ventral skin, milk, and nest extracts of mother contained 3-6 active substances. AF extracts contained 3 active compounds: ethylbenzene, benzaldehyde, and benzyl alcohol, and their mixture in similar proportions to those found in AF extracts, in a ratio, respectively, of 1:1:12 (700 ng), attracts pups as putative maternal attractant substances (MAS). These 3 AF substances have already been identified in milk, nipples, ventral wash, and nest extracts of mother, but not in feces. Moreover, anethole flavor incorporated in pregnant rat and mother's diet is also detected in AF, nipples, milk, and nest extracts and the pups are attracted to anethole odor, but not in the case of the no-anethole pups. MAS, combined with diet flavors present in the AF bath, represent olfactory signals as "maternal signature odors" (MSO) that are learned by fetus and pups. These findings open the way to improved understanding of the neurobiology of early olfactory learning and of the importance of evolutionarily conserved survival behavior in many mammal species.
authors.affiliation: Aix-Marseille Univ, CNRS, IMBE UMR 7263 (Institut Méditerranéen de la Biodiversité et d'Ecologie marine et continentale), IRD, Avignon Université, Faculté Saint Charles, 3, place Victor Hugo, Case 36 F-13331 Marseille cedex 03, France.
authors.forename: Leam
authors.initials: L
authors.lastname: Sreng
authors.affiliation: Aix-Marseille Univ, CNRS, LCE, Laboratoire de Chimie et Environnement, UMR 7376, Case 29, Faculté Saint Charles, 3, place Victor Hugo, F-13331 Marseille cedex 03, France and.
authors.forename: Brice
authors.initials: B
authors.lastname: Temime-Roussel
authors.affiliation: Aix-Marseille Univ, CNRS, LCE, Laboratoire de Chimie et Environnement, UMR 7376, Case 29, Faculté Saint Charles, 3, place Victor Hugo, F-13331 Marseille cedex 03, France and.
authors.forename: Henri
authors.initials: H
authors.lastname: Wortham
authors.affiliation: Aix-Marseille Univ, CNRS, Laboratoire de Neurosciences Cognitives, UMR 7291, Faculté Saint Charles, 3, place Victor Hugo, Case 36, F-13331 Marseille cedex 03, France.
authors.forename: Christiane
authors.initials: C
authors.lastname: Mourre
mesh_terms: D000653:Amniotic Fluid / Q000737:chemistry*; D000818:Animals; D000831:Animals, Newborn; D005260:Female; D008297:Male; D009812:Odorants / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D012903:Smell
keywords: amniotic fluid; diet; learning and memory; maternal signature; odor preference; rodents.