Corneal sensitivity and substance P in experimental herpes simplex keratitis in mice.

Experimental herpes simplex keratitis in the mouse produced a rapid fall in both corneal sensitivity and levels of corneal substance P (SP). This finding supports the association of SP with sensory neurones and shows that such levels can be used as an indication of damage to neurones resulting, for example, from infection with HSV. However, the delay in recovery of SP compared to the more rapid and complete recovery of sensitivity suggests that SP in the cornea is not directly involved in mediation of the blink reflex.