Because of the chemical nature of impulse and the axon-dendrite structure. Because of the chemical nature of impulse and the axon-dendrite structure. http://www.biologymad.com/nervoussystem/nerveimpulses.htm (Best technical explanation and excellent graphics and animations)
Newborns may sneeze, and this is typically attributed to the irritation of their nasal passages. The most common irritants, explains Dr. Iannelli, are smoke (and simply smoking outside is not enough), animal dander from pets in the house, dust mites, and mold.
While the occasional cat sneeze probably isn't cause for alarm, a recurring bout could signal more serious problems -- including some that could affect your health, too. Like us, most cats react to a nostril tickle with a sneeze. However, frequent sneezing, especially when one sneeze follows another and another, may signal allergies. The culprit could be pollen, dust mites, household cleaners or cigarette smoke, so pay attention to what's in the air.