These results are indicating that the learning and memory ability of socially isolated mice were significantly reduced, while treating animals with both L‐NNA and MK‐801 or their combination (at subeffective doses) can significantly shortening the escape latency and the percentage of time stayed in the target quadrant; furthermore, these data suggest that inhibition of NOS and NMDAR can improve the learning and memory impairment induced by SIS. This evidence concerns the gene NOS1 and memory.