Behavioral evidence of heterospecific bonding between the lamb and the human caregiver and mapping of associated brain network.
While behavioral mechanisms of bonding between young mammals and humans have been explored, brain structures involved in the establishment of such processes are still unknown. The aim of the study was to identify brain regions activated by the presence of the caregiver. Since human positive interaction plays an important role in the bonding process, activation of specific brain structures by stroking was also examined. Twenty-four female lambs reared in groups of three were fed and stroked daily by a female caregiver between birth and 5-7 weeks of age. At 4 weeks, an isolation-reunion-separation test and a choice test revealed that lambs developed a strong bond with their caregiver. At 5-7 weeks of age, lambs were socially isolated for 90min. They either remained isolated or met their caregiver who stroked them, or not, at regular intervals over a 90-min period. Neuronal activation was investigated at the end of the period for maximum c-Fos expression. Reunion with the caregiver appeased similarly the lambs whether stroking was provided or not. Stroking did not activate a specific brain network compared to no stroking. In both cases, brain regions associated with olfactory, visual and tactile cue processing were activated in the presence of the caregiver, suggesting a multisensory process involved. In addition, activation of the oxytocinergic system in the hypothalamic paraventricular nucleus induced by the presence of the caregiver suggests similar neuroendocrine mechanisms involved in inter-conspecific and animal-human bonding.
Groupe ISA Lille, Equipe CASE, 48 boulevard Vauban, 59046 Lille cedex, France; INRA, UMR85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France; CNRS, UMR7247, 37380 Nouzilly, France; Université François Rabelais de Tours, 37041 Tours, France; Institut Français du Cheval et de l'Equitation, 37380 Nouzilly, France.
Vanessa
V
Guesdon
INRA, UMR85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France; CNRS, UMR7247, 37380 Nouzilly, France; Université François Rabelais de Tours, 37041 Tours, France; Institut Français du Cheval et de l'Equitation, 37380 Nouzilly, France.
Raymond
R
Nowak
INRA, UMR85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France; CNRS, UMR7247, 37380 Nouzilly, France; Université François Rabelais de Tours, 37041 Tours, France; Institut Français du Cheval et de l'Equitation, 37380 Nouzilly, France.
Maryse
M
Meurisse
INRA, UMRH1213 Herbivores, 63122St. Genes Champanelle, France; Clermont Université, VetAgro Sup, UMR Herbivores, BP 10448, 63000 Clermont-Ferrand, France.
Xavier
X
Boivin
INRA, UMR85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France; CNRS, UMR7247, 37380 Nouzilly, France; Université François Rabelais de Tours, 37041 Tours, France; Institut Français du Cheval et de l'Equitation, 37380 Nouzilly, France.
Fabien
F
Cornilleau
INRA, UMR85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France; CNRS, UMR7247, 37380 Nouzilly, France; Université François Rabelais de Tours, 37041 Tours, France; Institut Français du Cheval et de l'Equitation, 37380 Nouzilly, France.
Elodie
E
Chaillou
INRA, UMR85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France; CNRS, UMR7247, 37380 Nouzilly, France; Université François Rabelais de Tours, 37041 Tours, France; Institut Français du Cheval et de l'Equitation, 37380 Nouzilly, France. Electronic address: frederic.levy@tours.inra.fr.
Frédéric
F
Lévy
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000378:metabolism; D001931:Brain Mapping / Q000379:methods / Q000523:psychology / Q000662:veterinary; D017028:Caregivers; D005260:Female; D001841:Human-Animal Bond; D006801:Humans; D009769:Object Attachment; D010121:Oxytocin / Q000378:metabolism / Q000502:physiology; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism / Q000502:physiology; D012756:Sheep; D034561:Sheep, Domestic / Q000523:psychology*
D010121:Oxytocin
Attachment; Multisensory; Oxytocin; Recognition; Sheep; Tactile contact