OBJECTIVETo assess the changes of neurobehavioral function in a neonatal mouse model of excitotoxic brain damage.

METHODSFifty-five 5-day-old ICR neonatal mice were randomly assigned to three groups: blank (no intravenous) control (n=20), saline control (n=20) and excitotoxic brain damage model (ibotenic acid treatment, n=15). Behavioral function was evaluated by the surface righting reflex test (postnatal days 6-10), the swimming test (postnatal days 8-12) and the Y-maze discrimination learning test (postnatal days 33-34).

RESULTSRighting time in the surface righting reflex test in the ibotenic acid treatment group on postnatal days 6-10 was more prolonged than that in the two control groups (p<0.05). Swimming test scores in the ibotenic acid treatment group were significantly lower than those in the two control groups (p<0.05). In the Y-maze discrimination learning test, the mice from the ibotenic acid treatment group performed significantly worse than two control groups, presenting with increased learning times (19.79+/-2.42 vs 16.29+/-2.48 or 16.30+/-2.37; p<0.05) and achieving a lower correct percentage (86.7% vs 96.5% or 95.0%) (p<0.05).

CONCLUSIONSThe developmental reflexes and learning and memory functions were impaired in neonatal mice following excitotoxic brain damage. Behavioral testing is useful in the evaluation of early developmental reflexes and long-term neurobehavioral outcome in neonatal mice with excitotoxic brain damage.