Fourteen days pregnant Wistar strain rats were fed powder or aqueous extract of the edible fungus MycoleptFodonoides aitchisonii. Nerve growth factor (NGF) concentrations were measured in the brain of newborn rats during the lactation period at 0, 7 and 14 days after the birth. Two M. aitchisonii-fed groups showed a significant increase in NGF concentrations in brain halves compared to those who were fed control feed at days 7 and 14. At day 21, NGF concentrations in the cerebral cortex and hippocampus were not significantly different among the three groups. After weaning, the young rats were fed the same test diet as their mothers. Ten days later, Morris water maze test was started. After the test, the rats were sacrificed and NGF concentrations in the cerebral cortex and hippocampus were measured. Significant NGF concentration increases were detected in the cerebral cortex for two M. aitchisonii-fed groups and in the hippocampus in the aqueous extract group. These results suggest that NGF in the brain reached the same levels by day 21, but that M. aitchisonii affected the growth rate in the lactation period. The learning test stimulated the brain and some compounds of M. aitchisonii enhanced NGF synthesis in rat cerebral cortex and hippocampus.