Abnormalities in Behaviour, Histology and Prefrontal Cortical Gene Expression Profiles Relevant to Schizophrenia in Embryonic Day 17 MAM-Exposed C57BL/6 Mice

Gestational and perinatal disruption of neural development increases the risk of developing schizophrenia (SCZ) later in life. Embryonic day 17 (E17) methylazoxymethanol (MAM) treatment leads to histological, physiological and behavioural abnormalities in post-puberty rats resembling those described in SCZ patients. However, the validity of E17 MAM-exposed mice as a SCZ model has not been explored. Here we treated E17 C57BL/6 mouse dams with various dosages of MAM. We found that this mouse strain was more vulnerable to MAM treatment than rats and there were gender difference in behavioural abnormalities, histological changes and prefrontal cortical gene expression profiles in MAM (7.5 mg/kg)-exposed mice. Both male and female MAM-exposed mice had deficits in prepulse inhibition but were normal in social interaction and novel object recognition tasks. Female MAM-exposed mice were hyperactive in spontaneous locomotion while male mice were normal. Consistently, only female MAM-exposed mice exhibited reduced brain weight, decreased size of prefrontal cortex (PFC) and enlarged lateral ventricles. Transcriptome analysis of the PFC revealed that there were more differentially expressed genes in female MAM-exposed mice than those in male mice. Moreover, expression of Pvalb, Arc and genes in their association networks were downregulated in the PFC of female MAM-exposed mice. These results show that E17 MAM-exposure in C57BL/6 mice leads to behavioural changes that mimic positive symptoms and sensorimotor gating deficits associated with SCZ. MAM-exposed female mice may be used to study gene expression changes, inhibitory neural circuit dysfunction and glutamatergic synaptic plasticity deficits related to SCZ. Prefrontal cortex mRNA profiles of E17 MAM-exposed mice were generated by deep sequencing, distinguishing gender, in triplicate, using Illumina X-10.