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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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The effect of parecoxib and fentanyl is evaluated by EEG parameters. Total power (A) was decreased during nociceptive stimulation, while MF (B), SEF (C), and the distance of cumulative power distribution (CPD) increased in response to noxious stimulation(D). Fentanyl (n = 12) significantly inhibited the response in each case and the inhibition was reversed by naloxone (n = 9). Parecoxib had no effect on the neuronal response to noxious stimulation (n = 11). Total power and distance of cumulative power distribution was normalized to pre-stimulation values. *P < 0.05, **P < 0.01, #P < 0.001, compared with pre-stim value.
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Figure 3: The effect of parecoxib and fentanyl is evaluated by EEG parameters. Total power (A) was decreased during nociceptive stimulation, while MF (B), SEF (C), and the distance of cumulative power distribution (CPD) increased in response to noxious stimulation(D). Fentanyl (n = 12) significantly inhibited the response in each case and the inhibition was reversed by naloxone (n = 9). Parecoxib had no effect on the neuronal response to noxious stimulation (n = 11). Total power and distance of cumulative power distribution was normalized to pre-stimulation values. *P < 0.05, **P < 0.01, #P < 0.001, compared with pre-stim value.

Mentions: The effects of parecoxib and fentanyl on cortical activity in response to acute mechanical pain were compared. Extracellular recordings at ACC and intracellular recordings at S1 in urethane anesthetized rats were obtained. EEG recordings revealed that normalized total power (Fig. 3A) was decreased, while MF (medial frequency; see Fig. 3B), SEF (95% spectral edge frequency; see Fig. 3C) and distance of cumulative power distribution (Fig. 3D) were increased by nociceptive stimulation compared to the resting state. Fentanyl significantly inhibited these effects, and moreover, its action was reversed by naloxone (see Fig. 3). Parecoxib administration, on the other hand, did not inhibit the observed response in any of these measures (Fig. 3).


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

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

The effect of parecoxib and fentanyl is evaluated by EEG parameters. Total power (A) was decreased during nociceptive stimulation, while MF (B), SEF (C), and the distance of cumulative power distribution (CPD) increased in response to noxious stimulation(D). Fentanyl (n = 12) significantly inhibited the response in each case and the inhibition was reversed by naloxone (n = 9). Parecoxib had no effect on the neuronal response to noxious stimulation (n = 11). Total power and distance of cumulative power distribution was normalized to pre-stimulation values. *P < 0.05, **P < 0.01, #P < 0.001, compared with pre-stim value.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: The effect of parecoxib and fentanyl is evaluated by EEG parameters. Total power (A) was decreased during nociceptive stimulation, while MF (B), SEF (C), and the distance of cumulative power distribution (CPD) increased in response to noxious stimulation(D). Fentanyl (n = 12) significantly inhibited the response in each case and the inhibition was reversed by naloxone (n = 9). Parecoxib had no effect on the neuronal response to noxious stimulation (n = 11). Total power and distance of cumulative power distribution was normalized to pre-stimulation values. *P < 0.05, **P < 0.01, #P < 0.001, compared with pre-stim value.
Mentions: The effects of parecoxib and fentanyl on cortical activity in response to acute mechanical pain were compared. Extracellular recordings at ACC and intracellular recordings at S1 in urethane anesthetized rats were obtained. EEG recordings revealed that normalized total power (Fig. 3A) was decreased, while MF (medial frequency; see Fig. 3B), SEF (95% spectral edge frequency; see Fig. 3C) and distance of cumulative power distribution (Fig. 3D) were increased by nociceptive stimulation compared to the resting state. Fentanyl significantly inhibited these effects, and moreover, its action was reversed by naloxone (see Fig. 3). Parecoxib administration, on the other hand, did not inhibit the observed response in any of these measures (Fig. 3).

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