Current Research
Following the discovery of the endorphins in 1975, nearly every major pharmaceutical company in Europe and the United States began searching for a synthesized relative of endorphins that could relieve pain with the potency of morphine, but not be addicting (Hughes et al., 1975; Snyder, 1996).  No one has been able to do it, yet.  However, producing a nonaddicting pain reliever is still under intense research (Bessen, 1999) 

Opiate receptors may be involved in biochemical abnormalities in people who are depressed.  One definition of depression is the inability to feel pleasure, which seems to be linked to an underactive opiate system (Fackelmann and Weiss, 1990).  Indeed, one study reports that suicide victims, who were depressed before death, have 800 percent more mu opiate receptors and 50 percent 

fewer delta receptors than people who died from other causes. An increase in the concentration of mu opiate receptors could be caused by a shortage of endorphins (Gross et al., 1990). 

Autism, which is characterized by infrequent displays of emotion and unresponsiveness to painful stimuli, might be related to an overactive opiate system.  According to one theory, autistic children have so many endorphins in their brain that the endorphins released during pleasurable and painful events have little effect on the overall concentration.  Autistic children are in a continuous state of euphoria and analgesia.  Supporting this theory is the finding that treating autistic children with an opiate antagonist, such as naloxone, improves their condition (Maranto, 1987). 



    Main Page   History 1    History 2    Ligands & Receptors   Endorphins    Opiate Receptors    Analgesia 1   Analgesia 2    Euphoria   Tolerance & Dependency   Common Opioids    Acknowledgments   Literature Cited

Animal Physiology HOT TOPICS
  This site was created during the fall semester of 1999 by Wes Self, a student at 
  Davidson College, as part of an assignment in Biology 312 (Animal Physiology). 

  Questions, comments and suggestions are appreciated at weself@davidson.edu