TORONTO -- Apparently, it doesn’t take a brain or a nervous system to have a good memory.

Physarum polycephalum, a bright yellow slime mold, has neither. Yet the peculiar single-cell organism has long intrigued scientists due to its ability to do things not normally expected of a substance that looks like it belongs on a puddle of old yogurt. It can, for instance, remember how to avoid noxious substances, find its way out of a maze, and hunt for food.

A study published this week in the journal Proceedings of the National Academy of Sciences offers some answers as to how it happens.

“The concept of memory is traditionally associated with organisms possessing a nervous system,” the study acknowledges.

But Physarum polycephalum solves this problem by encoding information in its network-like body of interlaced tubes. While a single-cell organism in the same classification as amoebas, multiple Physarum polycephalum can fuse together to form large networks that can be more than a foot across.

According the study, the tubes can grow and shrink in diameter in reaction to a food source, “thereby imprinting the nutrient’s location in the tube diameter hierarchy”. The tubes react to the food by growing near the food source and shrinking elsewhere, which means the tube’s capacity increases near the nutrient location, thus storing the location information within the tube structure itself.

“Our findings explain how network-forming organisms like slime molds and fungi thrive in complex environments,” the study says.