title: Deficit in attachment behavior in mice lacking the mu-opioid receptor gene.
abstract: Endogenous opioid binding to micro receptors is hypothesized to mediate natural rewards and has been proposed to be the basis of infant attachment behavior. Here, we report that micro-opioid receptor knockout mouse pups emit fewer ultrasonic vocalizations when removed from their mothers but not when exposed to cold or male mice odors. Moreover these knockout pups do not show a preference toward their mothers' cues and do not show ultrasonic calls potentiation after brief maternal exposure. Results from this study may indicate a molecular mechanism for diseases characterized by deficits in attachment behavior, such as autism or reactive attachment disorder.
authors.affiliation: Consiglio Nazionale delle Ricerche Institute of Neuroscience, Psychobiology and Psychopharmacology, Viale Marx 43, 00137 Roma, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Moles
authors.forename: Brigitte L
authors.initials: BL
authors.lastname: Kieffer
authors.forename: Francesca R
authors.initials: FR
authors.lastname: D'Amato
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001512:Bedding and Linens; D001522:Behavior, Animal; D003080:Cold Temperature; D003463:Cues; D005260:Female; D005838:Genotype; D008297:Male; D008425:Maternal Behavior; D008426:Maternal Deprivation; D051379:Mice; D018345:Mice, Knockout; D009035:Mothers; D009154:Mutation; D009769:Object Attachment; D009812:Odorants; D017450:Receptors, Opioid, mu / Q000235:genetics / Q000502:physiology*; D012201:Reward; D014828:Vocalization, Animal
chemical_list: D017450:Receptors, Opioid, mu