title: Social stress regulation in 4-month-old infants: contribution of maternal social engagement and infants' 5-HTTLPR genotype.
abstract: BACKGROUND
  Maternal behavior and infant 5-HTTLPR polymorphism have been linked to infants' social stress reactivity and recovery at different ages. Nonetheless, Gene×Environment (G×E) studies focusing on early infancy are rare and have led to mixed results.
  
  
  OBJECTIVE
  To investigate the contribution of maternal social engagement and infants' 5-HTTLPR polymorphism in predicting infants' negative emotionality in response to a social stressor, namely maternal unresponsiveness.
  
  
  METHODS
  Cross-sectional, G×E study.
  
  
  METHODS
  73 4-month-old infants and their mothers took part to the Face-to-Face Still-Face (FFSF) procedure.
  
  
  METHODS
  A micro-analytical coding of negative emotionality was adopted to measure infants' reactivity to social stress (Still-Face episode) and infants' recovery after social stress (Reunion episode). Maternal contribution was measured as maternal social engagement during the Play episode. Infants were genotyped as S-carriers or L-homozygotes.
  
  
  RESULTS
  The interplay between maternal social engagement and infants' genotype was found to be predictive of infants' negative emotionality during both Still-Face and Reunion episodes of the FFSF paradigm. The interaction highlighted that maternal social engagement predicted minor negative emotionality during Still-Face and Reunion episodes for S-carrier infants, but not for L-homozygotes.
  
  
  CONCLUSIONS
  Findings extend previous results on adults and children, highlighting that maternal behavior might be a protective factor for stress reactivity and regulation, especially for S-carrier infants who are at risk for heightened stress susceptibility.
authors: 0-3 Centre for the Study of Social Emotional Development of at Risk Infant, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy. Electronic address: rosario.montirosso@bp.lnf.it.
authors: Rosario
authors: R
authors: Montirosso
authors: 0-3 Centre for the Study of Social Emotional Development of at Risk Infant, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy.
authors: Livio
authors: L
authors: Provenzi
authors: Laboratory of Cellular Biochemistry and Molecular Biology, CRIBENS, Catholic University, Milan, Italy.
authors: Daniela
authors: D
authors: Tavian
authors: Pediatric Unit, Sacra Famiglia Hospital, Erba, Como, Italy.
authors: Francesco
authors: F
authors: Morandi
authors: Department of Statistics, Catholic University, Milan, Italy.
authors: Andrea
authors: A
authors: Bonanomi
authors: Laboratory of Cellular Biochemistry and Molecular Biology, CRIBENS, Catholic University, Milan, Italy.
authors: Sara
authors: S
authors: Missaglia
authors: Department of Psychology, University of MA, Boston, USA.
authors: Ed
authors: E
authors: Tronick
authors: Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy.
authors: Renato
authors: R
authors: Borgatti
mesh_terms: D000328:Adult; D005260:Female; D006720:Homozygote; D006801:Humans; D007223:Infant; D008297:Male; D008425:Maternal Behavior; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012919:Social Behavior; D013315:Stress, Psychological / Q000235:genetics* / Q000523:psychology
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins
keywords: 5-HTTLPR; G×E study; Mother–infant interaction; Social stress; Still-face