The squirrels of the species Urocitellus columbianus can retain spatial memories during the roughly nine months they spend in hibernation, according to a study published by the Royal Society.
The investigation sought to determine whether the animals can recall information acquired before a long period of torpor, during which brain activity drastically decreases. For this, the researchers used a maze inspired by the characteristics of the squirrels’ natural burrows.
Over two seasons, ten animals were familiarized with the maze before hibernation. After waking, they were again placed on the same route, and their performance was compared with that of eight Urocitellus columbianus that had no prior contact with the maze.
The animals that already knew the route performed between 41% and 98% better than those facing it for the first time, right at the first test after waking from hibernation.
The results suggest that spatial memory acquired before hibernation remains preserved during an extended period of torpor, despite the significant changes that occur in brain functioning.
The Urocitellus columbianus are particularly adapted to long periods of hibernation, able to remain up to nine months in this state of greatly reduced physiological activity.
For the researchers, the results show that brain changes associated with hibernation do not necessarily entail the loss of memories already acquired. The study thus points to the brain’s ability to maintain essential cognitive functions in these animals during prolonged periods of inactivity.
