MODULATORY TREATMENT OF NMDA RECEPTORS IN NEONATAL RATS AFFECTS COGNITIVE-BEHAVIOR IN ADULT AGE

The glutamatergic NMDA receptor is probably involved in establishing f unctional connections during development, and interference may promote or impair cognitive functions in adult age. In the present study, rat pups received one daily injection of the NMDA receptor partial agonis t D-cycloserine in various concentrations (3, 10, 50 mg/kg), the NMDA receptor antagonist (+/-)-HA-966 (30 mg/kg), or saline throughout post natal days 10-20 (Experiment 1). In Experiment 2, effects of the (+)-e nantiomer of HA-966 were similarly examined. The rats were tested in a novelty task in adult age (postnatal days 98-112). The results from E xperiment 1 show that injections of D-cycloserine in the concentration of 10 mg/kg or (+/-)-HA-966 caused a slight increase in locomotor act ivity only. The results from Experiment 2 show that (+)-HA-966-treated rats displayed reduced preference for novelty, a slight reduction in exploratory activity and locomotor behavior, and increased rate of gro oming. These results suggest that neonatal treatment with (+)-HA-966 c an impair cognitive behavior in adult life. It was not possible to rec ord any effects on cognitive function after neonatal administration of the glutamatergic agonist D-cycloserine.