scholarly journals Phorbol Ester Modulation of Ca2+ Channels Mediates Nociceptive Transmission in Dorsal Horn Neurones

2013 ◽  
Vol 6 (6) ◽  
pp. 777-787 ◽  
Author(s):  
Li Yang ◽  
Iqbal Topia ◽  
Toni Schneider ◽  
Gary Stephens
Keyword(s):  
Dorsal Horn ◽  
Phorbol Ester ◽  
Nociceptive Transmission ◽  
Dorsal Horn Neurones ◽  
Ca2 Channels

Opioids modulate N-methyl-D-aspartic acid (NMDA)-evoked responses of trigeminothalamic neurons

1996 ◽  
Vol 76 (3) ◽  
pp. 2093-2096 ◽  
Author(s):  
X. M. Wang ◽  
S. S. Mokha
Keyword(s):  
Nmda Receptor ◽  
Dorsal Horn ◽  
Aspartic Acid ◽  
Opioid Receptor ◽  
Receptor Agonist ◽  
Receptor Activation ◽  
Evoked Responses ◽  
Nociceptive Neurons ◽  
Nociceptive Transmission ◽  
Opioid Receptor Agonist

1. The present study investigated opioid-mediated modulation of N-methyl-D-aspartic acid (NMDA)-evoked responses of trigeminothalamic neurons in the superficial and deeper dorsal horn of the medulla (trigeminal nucleus caudalis) in rats anesthetized with urethane. 2. Microiontophoretic application of NMDA activated 18/19 trigeminothalamic neurons. Administration of [D-Ala2, N-Me-Phe4,Gly5-ol]-Enkephalin, a selective mu-opioid receptor agonist, reduced the NMDA-evoked responses in 77% of trigeminothalamic neurons. [D-Pen2,5]-Enkephalin, a selective delta-opioid receptor agonist, produced inhibition of NMDA-evoked responses in 36% of neurons. 3. We suggest that 1) NMDA-receptor activation excites trigeminothalamic nociceptive neurons and may, therefore, mediate nociceptive transmission in the medullary dorsal horn; and 2) the predominantly inhibitory modulation of NMDA-receptor-mediated responses of nociceptive trigeminothalamic neurons by activation of mu- and delta-opioid receptors may provide a neural mechanism for the antinociceptive actions of opioids.

scholarly journals Analgesic Effect of Acetaminophen: A Review of Known and Novel Mechanisms of Action

2020 ◽  
Vol 11 ◽  
Author(s):  
Nobuko Ohashi ◽  
Tatsuro Kohno
Keyword(s):  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Nociceptive Transmission ◽  
Spinal Dorsal ◽  
C Fibers ◽  
Trpv1 Receptors ◽  
The Brain

Acetaminophen is one of the most commonly used analgesic agents for treating acute and chronic pain. However, its metabolism is complex, and its analgesic mechanisms have not been completely understood. Previously, it was believed that acetaminophen induces analgesia by inhibiting cyclooxygenase enzymes; however, it has been considered recently that the main analgesic mechanism of acetaminophen is its metabolization to N-acylphenolamine (AM404), which then acts on the transient receptor potential vanilloid 1 (TRPV1) and cannabinoid 1 receptors in the brain. We also recently revealed that the acetaminophen metabolite AM404 directly induces analgesia via TRPV1 receptors on terminals of C-fibers in the spinal dorsal horn. It is known that, similar to the brain, the spinal dorsal horn is critical to pain pathways and modulates nociceptive transmission. Therefore, acetaminophen induces analgesia by acting not only on the brain but also the spinal cord. In addition, acetaminophen is not considered to possess any anti-inflammatory activity because of its weak inhibition of cyclooxygenase (COX). However, we also revealed that AM404 induces analgesia via TRPV1 receptors on the spinal dorsal horn in an inflammatory pain rat model, and these analgesic effects were stronger in the model than in naïve rats. The purpose of this review was to summarize the previous and new issues related to the analgesic mechanisms of acetaminophen. We believe that it will allow clinicians to consider new pain management techniques involving acetaminophen.

Superficial NK1 expressing spinal dorsal horn neurones modulate inhibitory neurotransmission mediated by spinal GABAA receptors

2007 ◽  
Vol 419 (3) ◽  
pp. 278-283 ◽  
Author(s):  
Wahida Rahman ◽  
Shafaq Sikander ◽  
Rie Suzuki ◽  
Stephen P. Hunt ◽  
Anthony H. Dickenson
Keyword(s):  
Dorsal Horn ◽  
Gabaa Receptors ◽  
Spinal Dorsal Horn ◽  
Spinal Dorsal ◽  
Inhibitory Neurotransmission ◽  
Dorsal Horn Neurones
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