Opioid peptides (DAGO-enkephalin, dynorphin A(1–13), BAM 22P) microinjected into the rat brainstem: comparison of their antinociceptive effect and their effect on neuronal firing in the rostral ventromedial medulla
Reference (54)
- et al.
Putative pain modulatory neurons in the rostral ventral medulla: reflex-related activity predicts effects of morphine
Brain Research
(1986) - et al.
Role of mu-opiate receptors in supraspinal opiate analgesia: a microinjection study
Brain Research
(1988) - et al.
The mu rather than the delta subtype of opioid receptor appears to be involved in enkephalin-induced analgesia
Eur. J. Pharmacol.
(1984) - et al.
Analgesic activity of intracerebroventricular administration of morphiceptin and beta-casomorphins: correlation with the morphine (mu) receptor binding affinity
Life Sci.
(1982) - et al.
Morphine microinjected into the periaqueductal gray has differential effects on 3 classes of medullary neurons
Brain Research
(1986) - et al.
(D-Pen,D-Pen) enkephalin (DPDPE): a delta-selective enkephalin with low affinity for μ-opiate binding sites
Eur. J. Pharmacol.
(1986) - et al.
Characterization of high affinity opioid binding sites in rat periaqueductal gray P2 membrane
Eur. J. Pharmacol.
(1989) - et al.
Endogenous opioid peptides: comparative evaluation of their receptor affinities in the mouse brain
Life Sci.
(1983) - et al.
Analogues of β-LPH61–64 possessing selective agonist activity at mu-opiate receptors
Eur. J. Pharmacol.
(1981) - et al.
Antinociceptive profile of dynorphin in the rat
Life Sci.
(1983)
Opioid peptides derived from pro-enkephalin A but not that from pro-enkephalin B are substantial analgesics after administration into brain of mice
Eur. J. Pharmacol.
I. Comparison of antinociceptive action of morphine in the periaqueductal gray, medial and paramedial medulla in the rat
Brain Research
Comparison of the antinociceptive action of mu and delta opioid receptor ligands in the periaqueductal gray matter, medial and paramedial ventral medulla in the rat as studied by the microinjection technique
Brain Research
Sites of analgesic action of dynorphin
Life Sci.
Dynorphin immunocytochemistry in the rat central nervous system
Peptides
Evaluation of the periaqueductal gray as a morphine-specific locus of action and examination of morphine-induced and stimulation-produced analgesia at coincident PAG loci
Brain Research
A new family of endogenous ‘big’ met-enkephalins from bovine adrenal medulla: purification and structure of docosa(BAM22P)- and eicosapeptide (BAM20P) with very potent opiate activity
Biophys. Res. Commun.
U50488H, a pure kappa receptor agonist with spinal analgesic loci in the mouse
Life Sci.
Nucleus raphe magnus lesions disrupt stimulation-produced analgesia from ventral but not dorsal midbrain areas in the rat
Brain Research
Morphine analgesia: blockade by raphe magnus lesions
Brain Research
Dynorphin A (1–13) antagonizes morphine analgesia in the brain and potentiates morphine analgesia in the spinal cord
Peptides
Relative contributions of the nucleus raphe magnus and adjacent medullary reticular formation to the inhibition by stimulation in the periaqueductal gray of a spinal nociceptive reflex in the pentobarbital-anesthetized rat
Brain Research
Comparison of analgesic potencies of mu, delta and kappa agonists locally applied to various CNS regions relevant to analgesia in rats
Life Sci.
The mu opiate receptor is responsible for descending pain inhibition
Eur. J. Pharmacol.
Midbrain stimulation inhibits tail-flick only at currents sufficient to excite rostral medullary neurons
Brain Research
Chronic catheterization of the spinal subarachnoid space
Physiol. Behav.
Studies on the antagonism by raphe lesions of the antinociceptive action of systemic morphine
Eur. J. Pharmacol.
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Pain, negative affective states and opioid-based analgesics: Safer pain therapies to dampen addiction
2021, International Review of NeurobiologyCitation Excerpt :They differ in their analgesic or pro-nociceptive properties and their response to opioid agonists (Basbaum & Fields, 1984; Fang, Haws, Drasner, Williamson, & Fields, 1989). Briefly, MOR agonists inhibit ON cells while they disinhibit OFF cells to produce antinociception (Fang et al., 1989). The selective engagement of MOR in a cell type-specific fashion remains an unrealistic task for human chronic pain therapies, with perhaps the exception of intrathecal (spinal) pumps for cancer pain treatment.
Endogenous opioid peptides in the descending pain modulatory circuit
2020, NeuropharmacologyCitation Excerpt :However, outstanding questions remain in regard to the role of endogenous opioids in the PAG, including the role for endogenous opioids in regulating glutamatergic inputs and the temporal and spatial distribution of their release. In the rat, microinjections of opioids directly into the PAG elicit antinociception (Siuciak and Advokat, 1987; Tortorici and Morgan, 2002; Tortorici et al., 2001; Yaksh et al., 1976) through activation of MORs, not KORs (Fang et al., 1989). It is clear that activation of PAG output neurons leads to antinociception but the exact circuitry between these PAG output neurons and well-described populations of RVM neurons, namely RVM ON- and OFF-cells (Heinricher and Ingram, 2008), is not understood.
5.15 - The Brainstem and Nociceptive Modulation
2020, The Senses: A Comprehensive Reference: Volume 1-7, Second EditionInflammatory mediators of opioid tolerance: Implications for dependency and addiction
2019, PeptidesCitation Excerpt :Our results further suggest that solTNF mediates morphine tolerance in the PAG via TNFRI signaling and augmentation of glutamate homeostasis. Given that PAG-mediated analgesia depends largely on the ability of opioids to inhibit vlPAG MOR-expressing GABAergic neurons [12,19,22,39,43,47,65,162–186], our data suggest that TLR4 signaling contributes to opioid tolerance by decreasing the ability of morphine to hyperpolarize vlPAG GABAergic neurons, thereby maintaining tonic inhibition of vlPAG-RVM projections neurons, and preventing opioid analgesia. Glia modulation of opioid tolerance has been reported at every major level of the descending analgesic circuit: PAG, RVM, and spinal cord dorsal horn.
Networks for the Modulation of Acute and Chronic Pain
2014, Neuronal Networks in Brain Function, CNS Disorders, and TherapeuticsMedullary circuits for nociceptive modulation
2012, Current Opinion in NeurobiologyCitation Excerpt :Without question, the tonic effects of opioids on on and off cell discharge are dramatic in the anesthetized rat. On cells stop firing and off cells fire continuously after administration of an opioid at any dose and by any route that suppresses nociceptive withdrawals [see for example [10–13]]. The robust and consistent finding that opioids change the tonic firing of on and off cells led to the suggestion that the tonic discharge of on and off cells mediates RVM modulation of nociception.