Tetanus vaccine ingredient improved learning and memory in aging mice

Twelve-month-old mice received tetanus toxoid, an inactivated toxin used in tetanus vaccines, in an animal experiment on learning and memory. The researchers assessed these abilities with tests of object recognition and navigation through mazes.

Mice given tetanus toxoid performed better on these tests. The improvements were associated with more immature nerve cells and a higher proportion of newly formed nerve cells in the hippocampus, a brain region involved in memory. The researchers also found greater insulation around nerve fibres in three brain regions. They found fewer cells carrying a marker of cell death in the brains of treated mice.