Behavioral and hippocampal changes after prenatal invasive interventions with possible relevance to schizophrenia

In an attempt to model neurodevelopmental defects that may contribute to the outbreak of schizophrenia after adolescence, the present study examined the effects of prenatal interventions in rats, including injections of kainic acid, on motor, cognitive and social behaviour, which was assessed repeatedly between PDs 56-62 (week 8) and 168-174 (week 24), as well as on hippocampal morphology. As compared to untreated controls (n=5-9), the offspring (n=12 or 16) of treated mothers exhibited shorter latencies to leave a dark box and enter an illuminated field on weeks 12, 16 and 20, a higher number of perseverations in a T-maze alternation task on weeks 16 and 20, longer nose contacts with strange and familiar partners in a social interaction test on weeks 12 and 16 and lower weight gains over the course of testing. They also had shorter pyramidal cells in hippocampal area CA3. Thus, the prenatally treated offspring showed certain alterations in their brains and behaviour that resembled the human condition of schizophrenia (e.g., changes at cell level in the hippocampus, perseverative behaviour, lower weight gains), although others (e.g., increased social contacts) did not.