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Indirect Opioid Actions on Inspiratory pre-Bötzinger Complex Neurons in Newborn Rat Brainstem Slices

  • Klaus Ballanyi
  • Bogdan Panaitescu
  • Araya Ruangkittisakul
Conference paper
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 669)

Abstract

Findings in newborn mouse brainstem slices led to the hypothesis that depression of breathing by opioids is caused by postsynaptic K+ channel-mediated hyperpolarization of rhythmogenic inspiratory neurons of the pre-Bötzinger complex (preBötC). Subsequent observations in newborn en bloc medullas and juvenile rats in vivo indicated that excitatory drive from retrotrapezoid nucleus/parafacial respiratory group (RTN/pFRG) neurons partly counters opioid-evoked inspiratory inhibition. Our recent study in newborn rat en bloc medullas supports the latter hypothesis, whereas we found in that report that inspiratory preBötC neurons constituting the interface with the RTN/pFRG are not hyperpolarized by opioids. Here, we show that opioids also do not hyperpolarize preBötC neurons in “calibrated” newborn rat slices. This supports the previous hypothesis by us and others that opioids rather target inspiratory networks indirectly, likely primarily via presynaptic mechanisms.

Keywords

Excitatory Drive Inspiratory Motor Inspiratory Neuron Action Potential Discharge Membrane Potential Recording 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

Supported by CIHR, AHFMR, CFI and ISRIP/ASRA. KB is a AHFMR Scientist. BP and AR have been awarded a CIHR studentship (MFN training grant).

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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Klaus Ballanyi
    • 1
  • Bogdan Panaitescu
    • 1
  • Araya Ruangkittisakul
    • 1
  1. 1.Department of PhysiologyUniversity of AlbertaEdnmtonCanada

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