As illustrated above, secreted pertussis toxin (BP toxin) from a colonizing virulent nasopharyngeal B. pertussis infection (BP) may access the CNS via the olfactory tract (black arrows) through channels in the cribriform plate, and localize to the olfactory bulb and its projections including the entorhinal cortex, hippocampus and amygdala. Early evidence suggests that pertussis toxin localization to and progression along neuroanatomic connections may lead to hallmark Alzheimer's pathology.