Objective: 

It is known that N-methyl-D-aspartate (NMDA) type of glutamate receptors in the brain play important roles in the development of neuronal migration and establishment of synaptic connections. NMDA receptor system in the neonatal or postnatal periods is supposed to play a crucial role in the neuropathology of schizophrenia. In our study, NMDA receptors that are known important for development of brain, in neonatal period blockade effects on short-term memory and anxiety have been investigated in adult C57BL/6 mice. Methods:

MK-801 (0.25 mg/kg, 0.1ml/20gr body weight, i.p.) was applied to C57BL/6 male mice between postnatal 7–10 days. The same volume of saline was injected into the control group. Anxiety behaviors were evaluated by using an open field (saline treated n=10, MK-801 treated n=13) and elevated plus maze test (saline treated n=13, MK-801 treated n=14) during the adult period. Short-term memory performances were evaluated by passive avoidance test (saline treated n=11, MK-801 treated n=10).

Results: 

The intraperitoneal treatment with MK-801 increased center latency (p<0.05) and the speed, decreased the time spent in center (p<0.01) of C57BL/6 mice compared to saline group in the open field test. NMDA receptor blockade with MK-801 decreased the time spent in open arm and number of entries to open arm (p<0.05) in the elevated plus maze. In the passive avoidance test, decreased the escape latency in C57BL/6 mice (p<0.05).

Conclusions: 

NMDA receptor blockade increased level of anxiety and locomotor activity in neonatal period, caused a decrease in the short-term memory performance. Neonatal NMDA receptor hypofunction may cause schizophrenia-like behaviors in the adults.