title: Emotional Contagion is not Altered in Mice Prenatally Exposed to Poly (I:C) on Gestational Day 9.
abstract: Prenatal immune activation has been associated with increased risk of developing schizophrenia. The polyinosinic-polycytidylic acid (Poly(I:C)) mouse model replicates some of the endophenotype characteristic of this disorder but the social deficits observed in schizophrenia patients have not been well studied in this model. Therefore we aimed to investigate social behavior, in particular emotional contagion for pain, in this mouse model. We injected pregnant mouse dams with Poly(I:C) or saline (control) on gestation day 9 (GD9) and we evaluated their offspring in the pre-pulse inhibition (PPI) test at age 50-55 days old to confirm the reliability of our model. Mice were then evaluated in an emotional contagion test immediately followed by the light/dark test to explore post-test anxiety-like behavior at 10 weeks of age. In the emotional contagion test, an observer (prenatally exposed to Poly(I:C) or to saline) witnessed a familiar wild-type (WT) mouse (demonstrator) receiving electric foot shocks. Our results replicate the sensory gating impairments in the Poly(I:C) offspring but we only observed minor group differences in the social tasks. One of the differences we found was that demonstrators deposited fewer feces in the presence of control observers than of observers prenatally exposed to Poly(I:C), which we suggest could be due to the observers' behavior. We discuss the findings in the context of age, sex and day of prenatal injection, suggesting that Poly(I:C) on GD9 may be a valuable tool to assess other symptoms or symptom clusters of schizophrenia but perhaps not comprising the social domain.
authors.affiliation: Department of Psychiatry, LWL University Hospital, Ruhr-University BochumBochum, Germany; International Graduate School of Neuroscience, Ruhr-University BochumBochum, Germany.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gonzalez-Liencres
authors.affiliation: Department of Psychiatry, LWL University Hospital, Ruhr-University BochumBochum, Germany; International Graduate School of Neuroscience, Ruhr-University BochumBochum, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Juckel
authors.affiliation: Department of Psychiatry, LWL University Hospital, Ruhr-University Bochum Bochum, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Esslinger
authors.affiliation: Department of Psychiatry, LWL University Hospital, Ruhr-University Bochum Bochum, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Wachholz
authors.affiliation: Department of Psychiatry, LWL University Hospital, Ruhr-University Bochum Bochum, Germany.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Manitz
authors.affiliation: Department of Psychiatry, LWL University Hospital, Ruhr-University BochumBochum, Germany; International Graduate School of Neuroscience, Ruhr-University BochumBochum, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Brüne
authors.affiliation: Department of Psychiatry, LWL University Hospital, Ruhr-University Bochum Bochum, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Friebe
keywords: Poly(I:C); empathy; maternal immune activation; schizophrenia; social behavior