Interactions between sucrose, pain and isolation distress

Pharmacol Biochem Behav. 1987 Mar;26(3):483-9. doi: 10.1016/0091-3057(87)90153-5.


Two experiments were conducted that establish an opioid-based, functional-relationship between the taste of sucrose, pain threshold and distress vocalization in isolated 10-day-old albino rats. In the first experiment intraoral infusion of sucrose virtually doubled heat-withdrawal latencies. This elevation was naltrexone (0.5 mg/kg b.wt.) reversible. In the second experiment sucrose infusions caused a rapid and sustained diminution of distress vocalizations in rats totally isolated from dam and siblings. These are the first demonstrations of a causal relationship between a positive affective system and ones mediating pain and stress.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Female
  • Male
  • Naltrexone / pharmacology
  • Pain / physiopathology*
  • Rats
  • Rats, Inbred Strains
  • Reaction Time / drug effects
  • Sensory Thresholds / drug effects
  • Social Isolation*
  • Sucrose / administration & dosage*
  • Taste / drug effects
  • Taste / physiology*
  • Vocalization, Animal / drug effects
  • Vocalization, Animal / physiology


  • Sucrose
  • Naltrexone