EFFECTS OF AGE ON BEHAVIORAL SIGNS OF NEUROPATHIC PAIN IN AN EXPERIMENTAL RAT MODEL

The present study examined the effect that aging has on the manifestat ions of pain behaviors in a rat model of neuropathic pain. Two experim ents were conducted. The first experiment compared young, mature and o ld rats. After tight ligation of the L5 and L6 segmental spinal nerves , young rats displayed much more vigorous behavioral signs of mechanic al allodynia and ongoing pain than did either mature or old rats, The second experiment was done using the same rats at two different time p oints. Spinal nerve ligation was done on the left side of rats when th ey were young and the same surgery was repeated on the right side 20 w eeks later (mature age). Comparison of pain behaviors between the left and right sides confirmed the results of the first experiment. The da ta suggest that younger rats show much more robust behavioral signs of neuropathic pain compared to older rats.