Influence of prenatal exposition to valproic acid in juvenile play behavior in rats

Background: The comprehension of cerebral dysfunctions related to the autism spectrum disorders (ASD) is important to develop new therapeutic interventions. Animal models are among the powerful tools to address this issue. The challenge is to build a model presenting behavioral alterations in the three domains of the ASD. Today, only one model seems to fulfill this demand, the BTBR mice (McFarlane et al, 2007). The prenatal expositions to valproic acid (VPA) in rats may be an alternative to this task.

Objectives: The aim of this research is to analyze the interference of VPA in the juvenile social play in wistar rats.

Methods: Pregnant females were treated by “gavage” with 800 mg/kg of VPA (SIGMA) at 9^th day of gestation (DG). At 28^th and 29^th postnatal days. pairs composed by animals from the same group were recorded for 10 min. each day. The juvenile play was evaluated by the intruder/resident paradigm. The exploratory locomotion, the playing soliciting and the social play were rated by blind investigators.

Results: The results of the experiment shows significant alterations in playing soliciting and social play in treated animals. Exploratory locomotion was preserved.

Conclusions: Prenatal exposure to valproic acid at 9^th DG produces alterations in the juvenile social interactions that can be related to those described in autistic persons. In other study, the same animals showed impairments in learning processes and routine flexibility.