Interference of age and repetition of the same noxious stimulus on hyperalgesia.

The article discusses research on the interference of age and repetition of similar noxious stimulus on the expression of hyperalgesia. The study procedure included the collection of 60 rats and their arrangement in three groups including a group of three-month-old rats, a group of six-month-old rats, and a group of nine-month-old rats. A formalin solution was injected in the plantar face of the hind paw of the subjects under anesthesia. Results revealed a difference between the hyperalgesia thresholds of younger and older rats.