Presentation of a distractor speeds the decay of a pentobarbital-insensitive nonopioid hypoalgesia in rats Academic Article uri icon


  • Higher psychological/neural processes are thought to be involved in brief, but not long, shock-induced hypoalgesia. Researchers have shown that three brief (0.75-sec) tailshocks produce a hypoalgesia that is eliminated by spinalization, decerebration, pentobarbital anesthesia, and a post-shock distractor. In contrast, three long (25-sec) tailshocks produce a hypoalgesia that is eliminated by spinalization but not decerebration. Although it has been assumed that this hypoalgesia would survive pentobarbital anesthesia and exposure to a distracting stimulus, this has not been previously tested. Experiment 1 demonstrates that pentobarbital has no effect on long shock-induced hypoalgesia. Contrary to our expectations, this nonopioid hypoalgesia was attenuated by a postshock distractor (Experiment 2). This distractor effect appears to be opioid mediated because it was blocked by naltrexone (Experiment 3) and a low dose of morphine effectively substituted for the distractor (Experiment 4). The role of memorial processing in hypoalgesia is discussed. 1995, Psychonomic Society, Inc.. All rights reserved.

published proceedings


author list (cited authors)

  • Meagher, M. W., Barter, J., King, T. E., & Grau, J. W.

citation count

  • 5

complete list of authors

  • Meagher, MW||Barter, J||King, TE||Grau, JW

publication date

  • January 1995