Effects of opiates and opiate antagonists on cortical neurones in naive and tolerant-dependent rats

  • M. Satoh
  • W. Zieglgänsberger
  • W. Fries
  • A. Herz
Chapter

Abstract

The basic mechanisms underlying acute and chronic actions of morphine-like compounds are still largely unknown. Studies using microelectrophoretic techniques on single neurones, mainly at the spinal and brainstem level, revealed a series of effects (Curtis and Duggan, 1969; Biscoe, Duggan and Lodge, 1972; Duggan and Curtis, 1972; Bradley and Dray, 1974; Bramwell and Bradley, 1974; Lodge, Headley, Duggan and Biscoe, 1974; Davies and Duggan, 1974). The relevance of the observed effects to the specific actions of opiates on the central nervous system (CNS), however, is far from being clear. Obviously, no microelectrophoretic studies have been performed so far on animals made tolerant to and dependent on morphine. Thus, in the present study, the effects of microelectrophoretically applied opiates, obtained in naive and tolerant—dependent rats, were compared with each other in order to obtain information about changes taking place at the single neurone level during adaptation of the CNS to chronic morphine exposure. As it was recently shown that (besides other structures) the sensory-motor cortex is rich in stereospecific morphine binding sites (Kuhar, Pert and Snyder, 1973), this structure seemed appro­priate for this study.

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Copyright information

© The Contributors 1976

Authors and Affiliations

  • M. Satoh
    • 1
  • W. Zieglgänsberger
    • 1
  • W. Fries
    • 1
  • A. Herz
    • 1
  1. 1.Department of NeuropharmacologyMax-Planck-Institut für PsychiatrieMunichWest Germany

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