Neurodevelopmental testing of mice in the neonatal period does not affect their locomotor activity, depressive- and anxiety-like behaviour in adolescence.

Neonatal life is a sensitive period of brain plasticity. There are concerns that pre-weaning handling may therefore alter behavioural phenotype in adolescence or adulthood. Since neurodevelopment tests require daily manipulation with pups, later behavioural outcomes might be biased by repeated handling during suckling period. The aim of our study was to assess whether daily neurodevelopmental testing would cause alterations in behavioural phenotype. Sixty-four CD1 mice were randomized to tested and not tested group. In the tested group, maturation of physical features and neurodevelopment were monitored daily from postnatal day 1-21 between 9 and 11 AM. After weaning, battery of behavioural tests to monitor anxiety-like, depressive, or repetitive behaviour was performed in all mice. We revealed no significant between-group differences in performance of these tests. Our data did not confirm the assumption that early neurodevelopment testing during suckling period affects behavioural phenotype in adolescence.