Advanced paternal age is associated with alterations in discrete behavioural domains and cortical neuroanatomy of C57BL/6J mice.

Advanced paternal age (APA) is associated with an increased risk of neurodevelopmental disorders such as autism and schizophrenia. A previous study in mice suggested that the offspring of aged sires have altered locomotion and avoidance learning. The aim of the current study was to conduct a comprehensive behavioural screen in adult offspring of mice of APA. We also examined brain morphology in neonate and adult mice. The adult offspring of 12- to 18-month-old (APA) and 4-month-old (control) male C57BL/6J mice underwent a behavioural test battery comprising tests for locomotion, anxiety, exploration, social behaviour, learned helplessness and sensorimotor gating. The brains of these mice were collected at 3 months and imaged ex vivo using a 16.4 T MRI scanner to assess gross neuroanatomy. Neuroanatomy was also examined at birth in a separate cohort of animals. Overall, the APA mouse model was associated with subtle behavioural changes and altered cortical morphology. The behavioural phenotype of female APA mice included increased anxiety-related behaviour, increased exploration and decreased learned helplessness compared to control females. Male APA mice had thinner cortices at birth and increased cortical volume as adults. This animal model may assist in exploring the mechanism of action linking APA with disorders such as schizophrenia and autism.