8 of 9

LESSON 5 · Parasites: The Invisible Puppeteers

Why Cat Smell Changes

Early studies suggested Toxoplasma changes how infected rodents respond to cat odor, possibly through limbic circuits and dopamine-related signaling. Later work made the story less tidy: infection may change several behaviors, not just one fear.

That still makes the parasite remarkable. It shows that infection can alter the nervous system in ways that may help a parasite reach its next host.