The immune system: uncharted pathways between senses and the brain

Humans and animals use the classic five senses-sight,hearing,touch,smell,and taste-to detect and monitor their environment,with the sense of position and movement often referred to as the sixth sense.The perception of external signals through the senses is essential to an organism's survival,transmitting signals to the central nervous system(CNS)and prompting physiological changes in other biological systems.In addition to the direct effects of sense-induced mediators in the brain,the perception of external signals can significantly affect the immune system that in turn can also affect the CNS and cognition.