[Behavioral analysis of consequences of chronic blockade of NMDA-type glutamate receptors in the early postnatal period in rats].

In view of the hypothesis that glutamatergic dysfunction of brain can underlie the negative symptoms of schizophrenia (including cognitive deficit), the aim of this study was to develop a model of cognitive impairment in Wistar male rats after administration of a noncompetitive NMDA-receptor antagonist in early postnatal period. Rat pups were daily subcutaneously injected with 0.05 mg/kg MK-801 on postnatal days 7-49. On the 27th and 28th days 24 h after the last previous injection, the MK-801-treated rats demonstrated lower spontaneous locomotor and exploratory activity in comparison with saline control, however, they retained the reaction of hyperlocomotion which developed immediately after the MK-801 administration. In these rats, the anxiety level in the elevated plus-maze (on the 40th postnatal day) was found to be decreased, and the spatial learning in food rewarded task was negatively affected (on the 50th-54th days). It is suggested that impairment of the input of sensory information and its correct assessment by the animals can be associated with the early neonatal blockade of NMDA glutamate receptors.