1
|
Klaey-Tassone M, Durand K, Damon F, Heyers K, Mezrai N, Patris B, Sagot P, Soussignan R, Schaal B. Human neonates prefer colostrum to mature milk: Evidence for an olfactory bias toward the "initial milk"? Am J Hum Biol 2020; 33:e23521. [PMID: 33151021 DOI: 10.1002/ajhb.23521] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/30/2020] [Accepted: 09/30/2020] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVES Colostrum is the initial milk secretion which ingestion by neonates warrants their adaptive start in life. Colostrum is accordingly expected to be attractive to newborns. The present study aims to assess whether colostrum is olfactorily attractive for 2-day-old newborns when presented against mature milk or a control. METHODS The head-orientation of waking newborns was videotaped in three experiments pairing the odors of: (a) colostrum (sampled on postpartum day 2, not from own mother) and mature milk (sampled on average on postpartum day 32, not from own mother) (n tested newborns = 15); (b) Colostrum and control (water; n = 9); and (c) Mature milk and control (n = 13). RESULTS When facing the odors of colostrum and mature milk, the infants turned their nose significantly longer toward former (32.8 vs 17.7% of a 120-s test). When exposed to colostrum against the control, they responded in favor of colostrum (32.9 vs 16.6%). Finally, when the odor of mature milk was presented against the control, their response appeared undifferentiated (26.7 vs 28.6%). CONCLUSIONS These results indicate that human newborns can olfactorily differentiate conspecific lacteal fluids sampled at different lactation stages. They prefer the odor of the mammary secretion - colostrum - collected at the lactation stage that best matches the postpartum age of their own mother. These results are discussed in the context of the earliest mother-infant chemo-communication. Coinciding maternal emission and offspring reception of chemosignals conveyed in colostrum may be part of the sensory precursors of attunement between mothers and infants.
Collapse
Affiliation(s)
- Magali Klaey-Tassone
- Developmental Ethology & Cognitive Psychology Laboratory, Centre for Smell, Taste and Feeding Behavior Science, UMR 6265 CNRS, Université de Bourgogne-Franche-Comté-Inrae-AgroSupDijon, Dijon, France
| | - Karine Durand
- Developmental Ethology & Cognitive Psychology Laboratory, Centre for Smell, Taste and Feeding Behavior Science, UMR 6265 CNRS, Université de Bourgogne-Franche-Comté-Inrae-AgroSupDijon, Dijon, France
| | - Fabrice Damon
- Developmental Ethology & Cognitive Psychology Laboratory, Centre for Smell, Taste and Feeding Behavior Science, UMR 6265 CNRS, Université de Bourgogne-Franche-Comté-Inrae-AgroSupDijon, Dijon, France
| | - Katrin Heyers
- Developmental Ethology & Cognitive Psychology Laboratory, Centre for Smell, Taste and Feeding Behavior Science, UMR 6265 CNRS, Université de Bourgogne-Franche-Comté-Inrae-AgroSupDijon, Dijon, France
| | - Nawel Mezrai
- Developmental Ethology & Cognitive Psychology Laboratory, Centre for Smell, Taste and Feeding Behavior Science, UMR 6265 CNRS, Université de Bourgogne-Franche-Comté-Inrae-AgroSupDijon, Dijon, France
| | - Bruno Patris
- Developmental Ethology & Cognitive Psychology Laboratory, Centre for Smell, Taste and Feeding Behavior Science, UMR 6265 CNRS, Université de Bourgogne-Franche-Comté-Inrae-AgroSupDijon, Dijon, France
| | - Paul Sagot
- Service de Gynécologie, Obstétrique et Biologie de la Reproduction, Centre Hospitalier Universitaire François Mitterrand, and Université de Bourgogne, Dijon, France
| | - Robert Soussignan
- Developmental Ethology & Cognitive Psychology Laboratory, Centre for Smell, Taste and Feeding Behavior Science, UMR 6265 CNRS, Université de Bourgogne-Franche-Comté-Inrae-AgroSupDijon, Dijon, France
| | - Benoist Schaal
- Developmental Ethology & Cognitive Psychology Laboratory, Centre for Smell, Taste and Feeding Behavior Science, UMR 6265 CNRS, Université de Bourgogne-Franche-Comté-Inrae-AgroSupDijon, Dijon, France
| | | |
Collapse
|
2
|
Klaey-Tassone M, Schaal B, Durand K, Patris B. The role of papillary skin glands in guiding mouse pups to the nipple. Dev Psychobiol 2020; 63:226-236. [PMID: 32643155 DOI: 10.1002/dev.22004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/15/2020] [Accepted: 05/26/2020] [Indexed: 11/05/2022]
Abstract
The nipple odor of lactating mice (Mus musculus) plays a crucial role in attracting newborn pups and motivating them to suck milk. The characteristic odor of a lactating murine nipple is assumed to be a mixture of multiple odorous substrates, that is, milk, dam's and pups' saliva, skin glands' secretions, and amniotic fluid. The present study aimed to characterize the behavioral activity of the original odor mixture that develops over the nipples in the first 2 days postpartum. We extracted this odor mixture in water and evaluated its attractive and appetitive potencies using two behavioral assays (viz., relative attraction and oral activation assays). It resulted that the so-called nipple wash was as appetitive as fresh milk, and even more attractive than it. The behavioral potency of the nipples was shown to be specific to lactating nipples (relative to nulliparous nipples) and to be preserved for 2 weeks when stored at -80°C. Finally, we perfected a nipple deodorization procedure by inactivating the nipples' behavioral potency. We observed that such altered appetitive potency was fully restored 30 min after its washing, but without any maternal self-licking and pups' sucking, indicating that the secretions of the nipple skin glands' were sufficient to explain the success of neonatal guidance to the nipple.
Collapse
Affiliation(s)
- Magali Klaey-Tassone
- Developmental Ethology & Cognitive Psychology Group, Taste and Food Sciences Research Centre, Dijon, France
| | - Benoist Schaal
- Developmental Ethology & Cognitive Psychology Group, Taste and Food Sciences Research Centre, Dijon, France
| | - Karine Durand
- Developmental Ethology & Cognitive Psychology Group, Taste and Food Sciences Research Centre, Dijon, France
| | - Bruno Patris
- Developmental Ethology & Cognitive Psychology Group, Taste and Food Sciences Research Centre, Dijon, France
| | | |
Collapse
|
3
|
Schaal B, Saxton TK, Loos H, Soussignan R, Durand K. Olfaction scaffolds the developing human from neonate to adolescent and beyond. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190261. [PMID: 32306879 PMCID: PMC7209940 DOI: 10.1098/rstb.2019.0261] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2020] [Indexed: 12/24/2022] Open
Abstract
The impact of the olfactory sense is regularly apparent across development. The fetus is bathed in amniotic fluid (AF) that conveys the mother's chemical ecology. Transnatal olfactory continuity between the odours of AF and milk assists in the transition to nursing. At the same time, odours emanating from the mammary areas provoke appetitive responses in newborns. Odours experienced from the mother's diet during breastfeeding, and from practices such as pre-mastication, may assist in the dietary transition at weaning. In parallel, infants are attracted to and recognize their mother's odours; later, children are able to recognize other kin and peers based on their odours. Familiar odours, such as those of the mother, regulate the child's emotions, and scaffold perception and learning through non-olfactory senses. During juvenility and adolescence, individuals become more sensitive to some bodily odours, while the timing of adolescence itself has been speculated to draw from the chemical ecology of the family unit. Odours learnt early in life and within the family niche continue to influence preferences as mate choice becomes relevant. Olfaction thus appears significant in turning on, sustaining and, in cases when mother odour is altered, disturbing adaptive reciprocity between offspring and carer during the multiple transitions of development between birth and adolescence. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.
Collapse
Affiliation(s)
- Benoist Schaal
- Developmental Ethology and Cognitive Psychology Laboratory, Centre des Sciences du Goût, UMR 6265 CNRS-Université de Bourgogne Franche-Comté, Inra-AgroSup, Dijon, France
| | - Tamsin K. Saxton
- Department of Psychology, Northumbria University, Newcastle upon Tyne, UK
| | - Hélène Loos
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Department of Sensory Analytics, Fraunhofer Institute for Process Engineering and Packaging IVV, Freising, Germany
| | - Robert Soussignan
- Developmental Ethology and Cognitive Psychology Laboratory, Centre des Sciences du Goût, UMR 6265 CNRS-Université de Bourgogne Franche-Comté, Inra-AgroSup, Dijon, France
| | - Karine Durand
- Developmental Ethology and Cognitive Psychology Laboratory, Centre des Sciences du Goût, UMR 6265 CNRS-Université de Bourgogne Franche-Comté, Inra-AgroSup, Dijon, France
| |
Collapse
|
4
|
Kollikowski A, Zimmermann E, Radespiel U. First experimental evidence for olfactory species discrimination in two nocturnal primate species (Microcebus lehilahytsara and M. murinus). Sci Rep 2019; 9:20386. [PMID: 31892739 PMCID: PMC6938479 DOI: 10.1038/s41598-019-56893-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 12/17/2019] [Indexed: 12/26/2022] Open
Abstract
Olfactory communication is highly important for nocturnal mammals, especially for solitary foragers, but knowledge is still limited for nocturnal primates. Mouse lemurs (Microcebus spp.) are nocturnal solitary foragers with a dispersed lifestyle and frequently use chemo-sensory signalling behaviour for governing social interactions. Different mouse lemur species can co-occur in a given forest but it is unknown whether olfaction is involved in species recognition. We first screened 24 captive mouse lemurs (9 M. murinus, 15 M. lehilahytsara) for their olfactory learning potential in an experimental arena and then tested the species discrimination ability with urine odour in an operant conditioning paradigm in four individuals. The majority of the screened animals (75%) did not pass the screening criteria within a 2-week test period. However, all four final test animals, two M. murinus and two M. lehilahytsara, were successfully trained in a 5-step-conditioning process to reliably discriminate conspecific from heterospecific urine odour (requiring an overall median of 293 trials). Findings complement previous studies on the role of acoustic signalling and suggest that olfaction may be an important additional mechanism for species discrimination.
Collapse
Affiliation(s)
- Annika Kollikowski
- Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Germany.
| | - Elke Zimmermann
- Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Ute Radespiel
- Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Germany
| |
Collapse
|
5
|
Coombes HA, Stockley P, Hurst JL. Female Chemical Signalling Underlying Reproduction in Mammals. J Chem Ecol 2018; 44:851-873. [PMID: 29992368 PMCID: PMC6096499 DOI: 10.1007/s10886-018-0981-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/31/2018] [Accepted: 06/25/2018] [Indexed: 12/21/2022]
Abstract
Chemical communication plays many key roles in mammalian reproduction, although attention has focused particularly on male scent signalling. Here, we review evidence that female chemical signals also play important roles in sexual attraction, in mediating reproductive competition and cooperation between females, and in maternal care, all central to female reproductive success. Female odours function not only to advertise sexual receptivity and location, they can also have important physiological priming effects on male development and sperm production. However, the extent to which female scents are used to assess the quality of females as potential mates has received little attention. Female investment in scent signalling is strongly influenced by the social structure and breeding system of the species. Although investment is typically male-biased, high competition between females can lead to a reversed pattern of female- biased investment. As among males, scent marking and counter-marking are often used to advertise territory defence and high social rank. Female odours have been implicated in the reproductive suppression of young or subordinate females across a range of social systems, with females of lower competitive ability potentially benefiting by delaying reproduction until conditions are more favourable. Further, the ability to recognise individuals, group members and kin through scent underpins group cohesion and cooperation in many social species, as well as playing an important role in mother-offspring recognition. However, despite the diversity of female scent signals, chemical communication in female mammals remains relatively understudied and poorly understood. We highlight several key areas of future research that are worthy of further investigation.
Collapse
Affiliation(s)
- Holly A Coombes
- Mammalian Behaviour and Evolution Group, Institute of Integrative Biology, University of Liverpool, Leahurst Campus, Chester High Road, Neston, CH64 7TE, UK.
| | - Paula Stockley
- Mammalian Behaviour and Evolution Group, Institute of Integrative Biology, University of Liverpool, Leahurst Campus, Chester High Road, Neston, CH64 7TE, UK
| | - Jane L Hurst
- Mammalian Behaviour and Evolution Group, Institute of Integrative Biology, University of Liverpool, Leahurst Campus, Chester High Road, Neston, CH64 7TE, UK
| |
Collapse
|