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Pavlovian conditioning of morphine-induced alterations of immune status

M E Coussons1, L A Dykstra, D T Lysle

  • 1Department of Psychology, University of North Carolina, Chapel Hill 27599-3270.

Journal of Neuroimmunology
|August 1, 1992
PubMed

Insights

Environmental cues can condition immune responses, as demonstrated by pairing distinct environments with morphine. This Pavlovian conditioning led to significant changes in immune cell activity and cytokine production in rats.

Area of Science:

  • Neuroimmunology
  • Behavioral Immunology
  • Psychoneuroimmunology

Background:

  • Immune system function can be influenced by external factors.
  • Pavlovian conditioning is a learning process where a neutral stimulus becomes associated with a biologically significant stimulus.

Purpose of the Study:

  • To investigate if immune status alterations can be conditioned to environmental stimuli paired with morphine administration.
  • To determine the specific immune measures affected by such conditioning.

Main Methods:

  • Rats received multiple conditioning sessions pairing a distinctive environment with morphine injections.
  • Subsequent re-exposure to the conditioned environment assessed immune responses, including lymphocyte mitogenesis, natural killer cell activity, and interleukin-2 production.
  • Control groups were used to confirm Pavlovian conditioning as the mechanism.

Main Results:

  • Conditioned environments paired with morphine decreased splenic lymphocyte mitogenic responsiveness and natural killer cell activity.
  • Interleukin-2 production was also decreased in response to the conditioned environment.
  • Immune alterations were compartment-specific, with mesenteric lymph node lymphocytes unaffected.

Conclusions:

  • Environmental stimuli paired with morphine can elicit conditioned alterations in immune status.
  • These findings demonstrate a link between learning processes and immune modulation.
  • Pavlovian conditioning is a key mechanism underlying these compartment-specific immune changes.

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