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Effects of Parecoxib and Fentanyl on nociception-induced cortical activity.

Peng YZ, Li XX, Wang YW - Mol Pain (2010)

Bottom Line: The effects of parecoxib and fentanyl on induced cortical activity were compared.Parecoxib, on the other hand, did not significantly affect the neural activity.Fentanyl showed a strong inhibitory effect on the nociceptive-stimulus induced cortical activity while parecoxib had no significant effect.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China.

ABSTRACT

Background: Analgesics, including opioids and non-steroid anti-inflammatory drugs reduce postoperative pain. However, little is known about the quantitative effects of these drugs on cortical activity induced by nociceptive stimulation. The aim of the present study was to determine the neural activity in response to a nociceptive stimulus and to investigate the effects of fentanyl (an opioid agonist) and parecoxib (a selective cyclooxygenase-2 inhibitor) on this nociception-induced cortical activity evoked by tail pinch. Extracellular recordings (electroencephalogram and multi-unit signals) were performed in the area of the anterior cingulate cortex while intracellular recordings were made in the primary somatosensory cortex. The effects of parecoxib and fentanyl on induced cortical activity were compared.

Results: Peripheral nociceptive stimulation in anesthetized rats produced an immediate electroencephalogram (EEG) desynchronization resembling the cortical arousal (low-amplitude, fast-wave activity), while the membrane potential switched into a persistent depolarization state. The induced cortical activity was abolished by fentanyl, and the fentanyl's effect was reversed by the opioid receptor antagonist, naloxone. Parecoxib, on the other hand, did not significantly affect the neural activity.

Conclusion: Cortical activity was modulated by nociceptive stimulation in anesthetized rats. Fentanyl showed a strong inhibitory effect on the nociceptive-stimulus induced cortical activity while parecoxib had no significant effect.

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Group data for relative power of each EEG band recorded from the ACC. δ band power was decreased while other band powers were increased in response to nociceptive stimulation. A: Parecoxib had no effect on band power response. B: Fentanyl completely inhibited the band power response to nociceptive stimulation and naloxone reversed its effect. *P < 0.05, **P < 0.01, #P < 0.001.
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Figure 4: Group data for relative power of each EEG band recorded from the ACC. δ band power was decreased while other band powers were increased in response to nociceptive stimulation. A: Parecoxib had no effect on band power response. B: Fentanyl completely inhibited the band power response to nociceptive stimulation and naloxone reversed its effect. *P < 0.05, **P < 0.01, #P < 0.001.

Mentions: There was a significant decrease in δ band power and an increase in other band powers when nociceptive stimulation was applied (Fig. 4A and 4B, control group), and a similar change was observed in the parecoxib group (Fig. 4A, right panel). However, there were no significant changes in any EEG band after fentanyl injected (fig 4B, middle panel). In addition, naloxone reversed the action of fentanyl (Fig. 4B, right panel).


Effects of Parecoxib and Fentanyl on nociception-induced cortical activity.

Peng YZ, Li XX, Wang YW - Mol Pain (2010)

Group data for relative power of each EEG band recorded from the ACC. δ band power was decreased while other band powers were increased in response to nociceptive stimulation. A: Parecoxib had no effect on band power response. B: Fentanyl completely inhibited the band power response to nociceptive stimulation and naloxone reversed its effect. *P < 0.05, **P < 0.01, #P < 0.001.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2819047&req=5

Figure 4: Group data for relative power of each EEG band recorded from the ACC. δ band power was decreased while other band powers were increased in response to nociceptive stimulation. A: Parecoxib had no effect on band power response. B: Fentanyl completely inhibited the band power response to nociceptive stimulation and naloxone reversed its effect. *P < 0.05, **P < 0.01, #P < 0.001.
Mentions: There was a significant decrease in δ band power and an increase in other band powers when nociceptive stimulation was applied (Fig. 4A and 4B, control group), and a similar change was observed in the parecoxib group (Fig. 4A, right panel). However, there were no significant changes in any EEG band after fentanyl injected (fig 4B, middle panel). In addition, naloxone reversed the action of fentanyl (Fig. 4B, right panel).

Bottom Line: The effects of parecoxib and fentanyl on induced cortical activity were compared.Parecoxib, on the other hand, did not significantly affect the neural activity.Fentanyl showed a strong inhibitory effect on the nociceptive-stimulus induced cortical activity while parecoxib had no significant effect.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China.

ABSTRACT

Background: Analgesics, including opioids and non-steroid anti-inflammatory drugs reduce postoperative pain. However, little is known about the quantitative effects of these drugs on cortical activity induced by nociceptive stimulation. The aim of the present study was to determine the neural activity in response to a nociceptive stimulus and to investigate the effects of fentanyl (an opioid agonist) and parecoxib (a selective cyclooxygenase-2 inhibitor) on this nociception-induced cortical activity evoked by tail pinch. Extracellular recordings (electroencephalogram and multi-unit signals) were performed in the area of the anterior cingulate cortex while intracellular recordings were made in the primary somatosensory cortex. The effects of parecoxib and fentanyl on induced cortical activity were compared.

Results: Peripheral nociceptive stimulation in anesthetized rats produced an immediate electroencephalogram (EEG) desynchronization resembling the cortical arousal (low-amplitude, fast-wave activity), while the membrane potential switched into a persistent depolarization state. The induced cortical activity was abolished by fentanyl, and the fentanyl's effect was reversed by the opioid receptor antagonist, naloxone. Parecoxib, on the other hand, did not significantly affect the neural activity.

Conclusion: Cortical activity was modulated by nociceptive stimulation in anesthetized rats. Fentanyl showed a strong inhibitory effect on the nociceptive-stimulus induced cortical activity while parecoxib had no significant effect.

Show MeSH
Related in: MedlinePlus