1
|
Posa L, De Gregorio D, Lopez-Canul M, He Q, Darcq E, Rullo L, Pearl-Dowler L, Luongo L, Candeletti S, Romualdi P, Kieffer BL, Gobbi G. Supraspinal melatonin MT 2 receptor agonism alleviates pain via a neural circuit that recruits mu opioid receptors. J Pineal Res 2022; 73:e12825. [PMID: 35996205 DOI: 10.1111/jpi.12825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 11/30/2022]
Abstract
Melatonin, through its G protein-coupled receptor (GPCR) (MTNR1B gene) MT2 , is implicated in analgesia, but the relationship between MT2 receptors and the opioid system remains elusive. In a model of rodent neuropathic pain (spared nerve injured [SNI]), the selective melatonin MT2 agonist UCM924 reversed the allodynia (a pain response to a non-noxious stimulus), and this effect was nullified by the pharmacological blockade or genetic inactivation of the mu opioid receptor (MOR), but not the delta opioid receptor (DOR). Indeed, SNI MOR, but not DOR knockout mice, did not respond to the antiallodynic effects of the UCM924. Similarly, the nonselective opioid antagonist naloxone and the selective MOR antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP) blocked the effects of UCM924 in SNI rats, but not the DOR antagonist naltrindole (NTI). Electrophysiological recordings in the rostral-ventromedial medulla (RVM) revealed that the typical reduction of the firing activity of pronociceptive ON-cells, and the enhancement of the firing of the antinociceptive OFF-cells, induced by the microinjection of the MT2 agonist UCM924 into the ventrolateral periaqueductal gray (vlPAG) were blocked by MOR, but not DOR, antagonism. Immunohistochemistry studies showed that MT2 receptors are expressed in both excitatory (CaMKIIα+ ) and inhibitory (GAD65+ ) neuronal cell bodies in the vlPAG (~2.16% total), but not RVM. Only 0.20% of vlPAG neurons coexpressed MOR and MT2 receptors. Finally, UCM924 treatment induced an increase in the enkephalin precursor gene (PENK) in the PAG of SNI mice. Collectively, the melatonin MT2 receptor agonism requires MORs to exert its antiallodynic effects, mostly through an interneuronal circuit involving MOR and MT2 receptors.
Collapse
Affiliation(s)
- Luca Posa
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University Health Center, McGill University, Montreal, Quebec, Canada
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Danilo De Gregorio
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University Health Center, McGill University, Montreal, Quebec, Canada
- Division of Neuroscience, Vita-Salute San Raffaele University, Italy, Milano
| | - Martha Lopez-Canul
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University Health Center, McGill University, Montreal, Quebec, Canada
| | - Qianzi He
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University Health Center, McGill University, Montreal, Quebec, Canada
| | - Emmanuel Darcq
- Department of Psychiatry, School of Medicine, Douglas Hospital Research Center, McGill University, Quebec, Montreal, Canada
| | - Laura Rullo
- Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Leora Pearl-Dowler
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University Health Center, McGill University, Montreal, Quebec, Canada
| | - Livio Luongo
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Sanzio Candeletti
- Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Patrizia Romualdi
- Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Brigitte Lina Kieffer
- Department of Psychiatry, School of Medicine, Douglas Hospital Research Center, McGill University, Quebec, Montreal, Canada
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University Health Center, McGill University, Montreal, Quebec, Canada
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
- McGill University, Health Center (MUHC), Montreal, Quebec, Canada
| |
Collapse
|
2
|
Bilella A, Alvarez-Bolado G, Celio MR. TheFoxb1-expressing neurons of the ventrolateral hypothalamic parvafox nucleus project to defensive circuits. J Comp Neurol 2016; 524:2955-81. [DOI: 10.1002/cne.24057] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 03/03/2016] [Accepted: 06/09/2016] [Indexed: 02/04/2023]
Affiliation(s)
- Alessandro Bilella
- Anatomy Unit and Program in Neuroscience, Department of Medicine, Faculty of Sciences, University of Fribourg; CH-1700 Fribourg Switzerland
| | - Gonzalo Alvarez-Bolado
- Institute of Anatomy and Cell Biology, University of Heidelberg; 69120 Heidelberg Germany
| | - Marco R. Celio
- Anatomy Unit and Program in Neuroscience, Department of Medicine, Faculty of Sciences, University of Fribourg; CH-1700 Fribourg Switzerland
| |
Collapse
|
3
|
Barbaresi P, Mensà E, Lariccia V, Desiato G, Fabri M, Gratteri S. Intracallosal neuronal nitric oxide synthase neurons colocalize with neurokinin 1 substance P receptor in the rat. J Comp Neurol 2014; 523:589-607. [PMID: 25312245 DOI: 10.1002/cne.23695] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 10/09/2014] [Accepted: 10/09/2014] [Indexed: 12/21/2022]
Abstract
The corpus callosum (cc) contains nitric oxide (NO)-producing neurons. Because NO is a potent vasodilator, these neurons could translate neuronal signals into vascular responses that can be detected by functional brain imaging. Substance P (SP), one of the most widely expressed peptides in the CNS, also produces vasomotor responses by inducing calcium release from intracellular stores through its preferred neurokinin 1 (NK1) receptor, thus inducing NO production via activation of neuronal NO synthase (nNOS). Single- and double-labeling experiments were performed to establish whether NK1-immunopositive neurons (NK1IP -n) are found in the rat cc and the extent of NK1 colocalization with nNOS. NK1IP -n were seen to constitute a large neuronal population in the cc and had a distribution similar to that of nNOSIP neurons (nNOSIP -n). NK1IP -n were numerous in the lateral cc and gradually decreased in the more medial portions, where they were few or absent. Intracallosal NK1IP -n and their dendritic trees were intensely labeled, allowing classification into four morphological types: bipolar, round, polygonal, and pyramidal. Confocal microscopic examination demonstrated that nearly all NK1IP -n contained nNOS (96.43%) and that 84.59% of nNOSIP -n co-expressed NK1. These data suggest that the majority of intracallosal neurons can release NO as a result of the action of SP. A small proportion of nNOSIP -n does not contain NK1 and is not activated by SP; these neurons may release NO via alternative mechanisms. The possible mechanisms by which intracallosal neurons release NO are also reviewed.
Collapse
Affiliation(s)
- Paolo Barbaresi
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Marche Polytechnic University, I-60020, Ancona, Italy
| | | | | | | | | | | |
Collapse
|