1
|
Mulloy SM, Aback EM, Gao R, Engel S, Pawaskar K, Win C, Moua A, Hillukka L, Lee AM. Subregion and sex differences in ethanol activation of cholinergic and glutamatergic cells in the mesopontine tegmentum. Sci Rep 2024; 14:46. [PMID: 38168499 PMCID: PMC10762073 DOI: 10.1038/s41598-023-50526-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 12/20/2023] [Indexed: 01/05/2024] Open
Abstract
Ethanol engages cholinergic signaling and elicits endogenous acetylcholine release. Acetylcholine input to the midbrain originates from the mesopontine tegmentum (MPT), which is composed of the laterodorsal tegmentum (LDT) and the pedunculopontine tegmental nucleus (PPN). We investigated the effect of acute and chronic ethanol administration on cholinergic and glutamatergic neuron activation in the PPN and LDT in male and female mice. We show that ethanol activates neurons of the PPN and not the LDT in male mice. Chronic 15 daily injections of 2 g/kg ethanol induced Fos expression in cholinergic and glutamatergic PPN neurons in male mice, whereas ethanol did not increase cholinergic and glutamatergic neuronal activation in the LDT. A single acute 4 g/kg injection, but not a single 2 g/kg injection, induced cholinergic neuron activation in the male PPN but not the LDT. In contrast, acute or chronic ethanol at either dose or duration had no effect on the activation of cholinergic or glutamatergic neurons in the MPT of female mice. Female mice had higher baseline level of activation in cholinergic neurons compared with males. We also found a population of co-labeled cholinergic and glutamatergic neurons in the PPN and LDT which were highly active in the saline- and ethanol-treated groups in both sexes. These findings illustrate the complex differential effects of ethanol across dose, time point, MPT subregion and sex.
Collapse
Affiliation(s)
- S M Mulloy
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - E M Aback
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - R Gao
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - S Engel
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - K Pawaskar
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - C Win
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - A Moua
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - L Hillukka
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - A M Lee
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA.
| |
Collapse
|
2
|
Ona G, Reverte I, Rossi GN, Dos Santos RG, Hallak JE, Colomina MT, Bouso JC. Main targets of ibogaine and noribogaine associated with its putative anti-addictive effects: A mechanistic overview. J Psychopharmacol 2023; 37:1190-1200. [PMID: 37937505 DOI: 10.1177/02698811231200882] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
BACKGROUND There is a growing interest in studying ibogaine (IBO) as a potential treatment for substance use disorders (SUDs). However, its clinical use has been hindered for mainly two reasons: First, the lack of randomized, controlled studies informing about its safety and efficacy. And second, IBO's mechanisms of action remain obscure. It has been challenging to elucidate a predominant mechanism of action responsible for its anti-addictive effects. OBJECTIVE To describe the main targets of IBO and its main metabolite, noribogaine (NOR), in relation to their putative anti-addictive effects, reviewing the updated literature available. METHODS A comprehensive search involving MEDLINE and Google Scholar was undertaken, selecting papers published until July 2022. The inclusion criteria were both theoretical and experimental studies about the pharmacology of IBO. Additional publications were identified in the references of the initial papers. RESULTS IBO and its main metabolite, NOR, can modulate several targets associated with SUDs. Instead of identifying key targets, the action of IBO should be understood as a complex modulation of multiple receptor systems, leading to potential synergies. The elucidation of IBO's pharmacology could be enhanced through the application of methodologies rooted in the polypharmacology paradigm. Such approaches possess the capability to describe multifaceted patterns within multi-target drugs. CONCLUSION IBO displays complex effects through multiple targets. The information detailed here should guide future research on both mechanistic and therapeutic studies.
Collapse
Affiliation(s)
- Genís Ona
- International Center for Ethnobotanical Education, Research, and Service (ICEERS), Barcelona, Spain
- Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira i Virgili, Tarragona, Spain
- Medical Anthropology Research Center (MARC), Universitat Rovira i Virgili, Tarragona, Spain
| | - Ingrid Reverte
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
- Santa Lucia Foundation (IRCCS Fondazione Santa Lucia), Rome, Italy
| | - Giordano N Rossi
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Rafael G Dos Santos
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- National Institute for Translational Medicine (INCT-TM), CNPq, Ribeirão Preto (SP), Brazil
| | - Jaime Ec Hallak
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- National Institute for Translational Medicine (INCT-TM), CNPq, Ribeirão Preto (SP), Brazil
| | - Maria Teresa Colomina
- Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira i Virgili, Tarragona, Spain
| | - José Carlos Bouso
- International Center for Ethnobotanical Education, Research, and Service (ICEERS), Barcelona, Spain
- Medical Anthropology Research Center (MARC), Universitat Rovira i Virgili, Tarragona, Spain
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| |
Collapse
|
3
|
Mulloy SM, Aback EM, Gao R, Engel S, Pawaskar K, Win C, Moua A, Hillukka L, Lee AM. Subregion and sex differences in ethanol activation of cholinergic and glutamatergic cells in the mesopontine tegmentum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.08.566053. [PMID: 38014248 PMCID: PMC10680559 DOI: 10.1101/2023.11.08.566053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Ethanol engages cholinergic signaling and elicits endogenous acetylcholine release. Acetylcholine input to the midbrain originates from the mesopontine tegmentum (MPT), which is composed of the laterodorsal tegmentum (LDT) and the pedunculopontine tegmental nucleus (PPN). We investigated the effect of acute and chronic ethanol administration on cholinergic and glutamatergic neuron activation in the PPN and LDT in male and female mice. We show that ethanol selectively activates neurons of the PPN and not the LDT in male mice. Acute 4.0 g/kg and chronic 15 daily injections of 2.0 g/kg i.p. ethanol induced Fos expression in cholinergic and glutamatergic PPN neurons in male mice, whereas cholinergic and glutamatergic neurons of the LDT were unresponsive. In contrast, acute or chronic ethanol at either dose or duration had no effect on the activation of cholinergic or glutamatergic neurons in the MPT of female mice. Female mice had higher level of baseline activation in cholinergic neurons compared with males. We also found a population of co-labeled cholinergic and glutamatergic neurons in the PPN and LDT which were highly active in the saline- and ethanol-treated groups in both sexes. These findings illustrate the complex differential effects of ethanol across dose, time point, MPT subregion and sex.
Collapse
Affiliation(s)
- S M Mulloy
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - E M Aback
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - R Gao
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - S Engel
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - K Pawaskar
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - C Win
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - A Moua
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - L Hillukka
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - A M Lee
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, USA
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
4
|
Brynildsen JK, Yang K, Lemchi C, Dani JA, De Biasi M, Blendy JA. A common SNP in Chrna5 enhances morphine reward in female mice. Neuropharmacology 2022; 218:109218. [PMID: 35973602 DOI: 10.1016/j.neuropharm.2022.109218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 08/01/2022] [Accepted: 08/08/2022] [Indexed: 11/25/2022]
Abstract
The single nucleotide polymorphism (SNP) D398N (rs16969968) in CHRNA5, the gene encoding the α5 subunit of the nicotinic acetylcholine receptors (nAChR), has been associated with both nicotine and opiate dependence in human populations. Expression of this SNP on presynaptic VTA dopaminergic (DA) neurons is known to cause a reduction in calcium signaling, leading to alterations in transmitter signaling and altered responses to drugs of abuse. To examine the impact of the Chrna5 SNP on opiate reward and underlying dopaminergic mechanisms, mice harboring two copies of the risk-associated allele (Chrna5 A/A) at a location equivalent to human rs16969968 were generated via CRISPR/cas9 genome editing. We sought to determine whether Chrna5 A/A mice show differences in sensitivity to rewarding properties of morphine using the conditioned place preference paradigm. When mice were tested two weeks after conditioning, female Chrna5 A/A mice showed significantly enhanced preference for the morphine-paired chamber relative to WT females, suggesting that this genotype may enhance opioid reward specifically in females. In contrast, Chrna5 genotype had no effect on locomotor sensitization in male or female mice. Relative to WT females, peak amplitude of ACh-gated currents recorded from VTA DA neurons in Chrna5 A/A females was potentiated 1 day after conditioning with morphine. Increased FOS expression was also observed in Chrna5 A/A mice relative to WT mice following exposure to the morphine CPP chamber. We propose that impaired α5 nAChR subunit function alters DA neuron response following repeated morphine exposures, and that this early cellular response could contribute to enhanced opiate reward two weeks after conditioning.
Collapse
Affiliation(s)
| | | | - Crystal Lemchi
- Department of Systems Pharmacology and Translational Therapeutics, USA
| | | | - Mariella De Biasi
- Department of Neuroscience, USA; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Julie A Blendy
- Department of Systems Pharmacology and Translational Therapeutics, USA.
| |
Collapse
|
5
|
Palandri J, Smith SL, Heal DJ, Wonnacott S, Bailey CP. Contrasting effects of the α7 nicotinic receptor antagonist methyllycaconitine in different rat models of heroin reinstatement. J Psychopharmacol 2021; 35:1204-1215. [PMID: 33691518 PMCID: PMC8521373 DOI: 10.1177/0269881121991570] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND α7 Nicotinic acetylcholine receptors are implicated in the reinstatement of drug-seeking, an important component of relapse. We showed previously that the α7 nicotinic acetylcholine receptor antagonist, methyllycaconitine, specifically attenuated morphine-primed reinstatement of conditioned place preference in rodents and this effect was mediated in the ventral hippocampus. AIMS The purpose of this study was to evaluate α7 nicotinic acetylcholine receptor antagonism in reinstatement of the conditioned place preference for the more widely abused opioid, heroin, and to compare the effect of α7 nicotinic acetylcholine receptor blockade on reinstatement of heroin-seeking and heroin self-administration in an intravenous self-administration model of addictive behaviour. METHODS Rats were trained to acquire heroin conditioned place preference or heroin self-administration; both followed by extinction of responding. Methyllycaconitine or saline was given prior to reinstatement of drug-primed conditioned place preference, or drug-prime plus cue-induced reinstatement of intravenous self-administration, using two protocols: without delivery of heroin in response to lever pressing to model heroin-seeking, or with heroin self-administration, using fixed and progressive ratio reward schedules, to model relapse. RESULTS Methyllycaconitine had no effect on acquisition of heroin conditioned place preference or lever-pressing for food rewards. Methyllycaconitine blocked reinstatement of heroin-primed conditioned place preference. Methyllycaconitine did not prevent drug-prime plus cue-induced reinstatement of heroin-seeking, reinstatement of heroin self-administration, or diminish the reinforcing effect of heroin. CONCLUSIONS The α7 nicotinic acetylcholine receptor antagonist, methyllycaconitine, prevented reinstatement of the opioid conditioned place preference, consistent with a role for α7 nicotinic acetylcholine receptors in the retrieval of associative memories of drug liking. The lack of effect of methyllycaconitine in heroin-dependent rats in two intravenous self-administration models suggests that α7 nicotinic acetylcholine receptors do not play a role in later stages of heroin abuse.
Collapse
Affiliation(s)
| | - Sharon L Smith
- RenaSci Ltd, BioCity, Nottingham, UK,DevelRx Ltd, BioCity, Nottingham, UK
| | - David J Heal
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK,DevelRx Ltd, BioCity, Nottingham, UK
| | - Sue Wonnacott
- Department of Biology and Biochemistry, University of Bath, Bath, UK
| | - Chris P Bailey
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK,Chris P Bailey, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| |
Collapse
|
6
|
Altarifi AA, Moerke MJ, Alsalem MI, Negus SS. Preclinical assessment of tramadol abuse potential: Effects of acute and repeated tramadol on intracranial self-stimulation in rats. J Psychopharmacol 2020; 34:269881120944153. [PMID: 32842842 DOI: 10.1177/0269881120944153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Tramadol is a widely used analgesic that activates mu-opioid receptors (MOR) and inhibits serotonin and norepinephrine transporters. This mixed pharmacology may limit both its own abuse potential and its modulation of abuse potential of other MOR agonists. AIMS This study used an intracranial self-stimulation (ICSS) procedure to compare abuse-related effects produced by acute or repeated treatment with tramadol or morphine in rats. Abuse potential in ICSS procedures is indicated by a drug-induced increase (or 'facilitation') of ICSS responding. METHODS Adult male Sprague-Dawley rats were implanted with electrodes targeting the medial forebrain bundle and trained to respond on a lever for pulses of electrical brain stimulation. Tramadol effects were evaluated after acute administration (3.2-32 mg/kg) in the absence or presence of the opioid antagonist naltrexone, the CYP2D6 hepatic-enzyme inhibitor quinine or a combination of both. Additionally, both tramadol and morphine were also tested before and after repeated tramadol (32 mg/kg/day for six days) or repeated morphine (3.2 mg/kg/day for six days). RESULTS Acute tramadol produced primarily ICSS rate-decreasing effects that were antagonised by naltrexone but not by quinine or naltrexone + quinine. Tramadol also produced little or no ICSS facilitation after repeated tramadol or repeated morphine, and repeated tramadol did not enhance ICSS facilitation by morphine. By contrast, morphine-induced ICSS facilitation was enhanced by repeated morphine treatment. CONCLUSIONS These results suggest that tramadol has lower abuse potential than other abused MOR agonists and that repeated tramadol exposure produces relatively little enhancement of abuse potential of other MOR agonists.
Collapse
Affiliation(s)
- Ahmad A Altarifi
- Department of Pharmacology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan
| | - Megan J Moerke
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, USA
| | - Mohammad I Alsalem
- Department of Anatomy and Histology, Faculty of Medicine, The University of Jordan, Amman, Jordan
| | - S Stevens Negus
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, USA
| |
Collapse
|
7
|
Jensen KP, DeVito EE, Yip S, Carroll KM, Sofuoglu M. The Cholinergic System as a Treatment Target for Opioid Use Disorder. CNS Drugs 2018; 32:981-996. [PMID: 30259415 PMCID: PMC6314885 DOI: 10.1007/s40263-018-0572-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Opioid overdoses recently became the leading cause of accidental death in the US, marking an increase in the severity of the opioid use disorder (OUD) epidemic that is impacting global health. Current treatment protocols for OUD are limited to opioid medications, including methadone, buprenorphine, and naltrexone. While these medications are effective in many cases, new treatments are required to more effectively address the rising societal and interpersonal costs associated with OUD. In this article, we review the opioid and cholinergic systems, and examine the potential of acetylcholine (ACh) as a treatment target for OUD. The cholinergic system includes enzymes that synthesize and degrade ACh and receptors that mediate the effects of ACh. ACh is involved in many central nervous system functions that are critical to the development and maintenance of OUD, such as reward and cognition. Medications that target the cholinergic system have been approved for the treatment of Alzheimer's disease, tobacco use disorder, and nausea. Clinical and preclinical studies suggest that medications such as cholinesterase inhibitors and scopolamine, which target components of the cholinergic system, show promise for the treatment of OUD and further investigations are warranted.
Collapse
Affiliation(s)
- Kevin P Jensen
- Department of Psychiatry and VA Connecticut Healthcare System, Yale University, School of Medicine, 950 Campbell Ave, Bldg 36/116A4, West Haven, CT, 06516, USA
| | - Elise E DeVito
- Department of Psychiatry and VA Connecticut Healthcare System, Yale University, School of Medicine, 950 Campbell Ave, Bldg 36/116A4, West Haven, CT, 06516, USA
| | - Sarah Yip
- Department of Psychiatry and VA Connecticut Healthcare System, Yale University, School of Medicine, 950 Campbell Ave, Bldg 36/116A4, West Haven, CT, 06516, USA
| | - Kathleen M Carroll
- Department of Psychiatry and VA Connecticut Healthcare System, Yale University, School of Medicine, 950 Campbell Ave, Bldg 36/116A4, West Haven, CT, 06516, USA
| | - Mehmet Sofuoglu
- Department of Psychiatry and VA Connecticut Healthcare System, Yale University, School of Medicine, 950 Campbell Ave, Bldg 36/116A4, West Haven, CT, 06516, USA.
| |
Collapse
|
8
|
Zhang C, Liu X, Zhou P, Zhang J, He W, Yuan TF. Cholinergic tone in ventral tegmental area: Functional organization and behavioral implications. Neurochem Int 2018; 114:127-133. [DOI: 10.1016/j.neuint.2018.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 01/20/2018] [Accepted: 02/01/2018] [Indexed: 11/29/2022]
|
9
|
Goins EC, Bajic D. Astrocytic hypertrophy in the rat ventral tegmental area following chronic morphine differs with age. JOURNAL OF NEUROLOGY AND NEUROREHABILITATION RESEARCH 2018; 3:14-21. [PMID: 29782623 PMCID: PMC5959292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The ventral tegmental area (VTA) is the origin of the mesolimbic dopaminergic system known to play an integral role in mediating reward and development of drug addiction. Although the differences in neuronal plasticity of VTA at various ages remain to be understood, age is known to influence the effects of chronic opioids. In addition, adaptations associated with exposure to opioids within glial populations located in the VTA are poorly understood. The objective of the study was to determine if there are changes in astrocytic immunofluorescent labeling in the VTA following chronic morphine administration in a rat model at different ages: newborn at postnatal day (PD)7 and adult (estimated PD57). We hypothesized that increased immunohistochemical labeling of an astrocytic marker, glial fibrillary acidic protein (GFAP) in the VTA following chronic administration of morphine will not differ with age. Two groups of rats were analyzed: chronic morphine and saline control treatment groups. Either morphine (10 mg/kg) or equal volume of saline was given subcutaneously twice daily for 6½ days. On the 7th day of treatment, animals were anesthetized and perfused at one hour after the final drug injection. Coronal sections of the midbrain were processed for immunofluorescent identification of GFAP that was noted at both ages. We report an increase in both (1) GFAP labeling intensity, as well as (2) the percent area occupied by astrocytes that are immunoreactive for GFAP following chronic morphine when compared to saline treatment in the VTA only for the adults (n=6/group) but not infant rats at PD7 (n=5/group). Our findings suggest that adaptations in the mesolimbic dopaminergic system produced by repeated exposure to opioids may be associated with changes in glial function that differ with age.
Collapse
Affiliation(s)
- Emily C Goins
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, USA
| | - Dusica Bajic
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, USA
- Department of Anaesthesia, Harvard Medical School, Boston, USA
| |
Collapse
|
10
|
Opioid-induced rewards, locomotion, and dopamine activation: A proposed model for control by mesopontine and rostromedial tegmental neurons. Neurosci Biobehav Rev 2017; 83:72-82. [PMID: 28951251 DOI: 10.1016/j.neubiorev.2017.09.022] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 08/12/2017] [Accepted: 09/21/2017] [Indexed: 01/06/2023]
Abstract
Opioids, such as morphine or heroin, increase forebrain dopamine (DA) release and locomotion, and support the acquisition of conditioned place preference (CPP) or self-administration. The most sensitive sites for these opioid effects in rodents are in the ventral tegmental area (VTA) and rostromedial tegmental nucleus (RMTg). Opioid inhibition of GABA neurons in these sites is hypothesized to lead to arousing and rewarding effects through disinhibition of VTA DA neurons. We review findings that the laterodorsal tegmental (LDTg) and pedunculopontine tegmental (PPTg) nuclei, which each contain cholinergic, GABAergic, and glutamatergic cells, are important for these effects. LDTg and/or PPTg cholinergic inputs to VTA mediate opioid-induced locomotion and DA activation via VTA M5 muscarinic receptors. LDTg and/or PPTg cholinergic inputs to RMTg also modulate opioid-induced locomotion. Lesions or inhibition of LDTg or PPTg neurons reduce morphine-induced increases in forebrain DA release, acquisition of morphine CPP or self-administration. We propose a circuit model that links VTA and RMTg GABA with LDTg and PPTg neurons critical for DA-dependent opioid effects in drug-naïve rodents.
Collapse
|
11
|
Naser PV, Kuner R. Molecular, Cellular and Circuit Basis of Cholinergic Modulation of Pain. Neuroscience 2017; 387:135-148. [PMID: 28890048 PMCID: PMC6150928 DOI: 10.1016/j.neuroscience.2017.08.049] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 08/26/2017] [Accepted: 08/29/2017] [Indexed: 12/17/2022]
Abstract
In addition to being a key component of the autonomic nervous system, acetylcholine acts as a prominent neurotransmitter and neuromodulator upon release from key groups of cholinergic projection neurons and interneurons distributed across the central nervous system. It has been more than forty years since it was discovered that cholinergic transmission profoundly modifies the perception of pain. Directly activating cholinergic receptors or extending the action of endogenous acetylcholine via pharmacological blockade of acetylcholine esterase reduces pain in rodents as well as humans; conversely, inhibition of muscarinic cholinergic receptors induces nociceptive hypersensitivity. Here, we aim to review the considerable progress in our understanding of peripheral, spinal and brain contributions to cholinergic modulation of pain. We discuss the distribution of cholinergic neurons, muscarinic and nicotinic receptors over the central nervous system and the synaptic and circuit-level modulation by cholinergic signaling. AchRs profoundly regulate nociceptive transmission at the level of the spinal cord via pre- as well as postsynaptic mechanisms. Moreover, we attempt to provide an overview of how some of the salient regions in the pain network spanning the brain, such as the primary somatosensory cortex, insular cortex, anterior cingulate cortex, the medial prefrontal cortex and descending modulatory systems are influenced by cholinergic modulation. Finally, we critically discuss the clinical relevance of cholinergic signaling to pain therapy. Cholinergic mechanisms contribute to several both conventional as well as unorthodox forms of pain treatments, and reciprocal interactions between cholinergic and opioidergic modulation impact on the function and efficacy of both opioids and cholinomimetic drugs.
Collapse
Affiliation(s)
- Paul V Naser
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany.
| | - Rohini Kuner
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany; Cell Networks Cluster of Excellence, Heidelberg University, Germany.
| |
Collapse
|
12
|
Sun J, Tian L, Cui R, Ruan H, Li X. Muscarinic acetylcholine receptor but not nicotinic acetylcholine receptor plays a role in morphine-induced behavioral sensitization in rats. Pharmacol Biochem Behav 2017; 160:39-46. [DOI: 10.1016/j.pbb.2017.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 07/19/2017] [Accepted: 08/10/2017] [Indexed: 12/11/2022]
|
13
|
McLaughlin I, Dani JA, De Biasi M. The medial habenula and interpeduncular nucleus circuitry is critical in addiction, anxiety, and mood regulation. J Neurochem 2017; 142 Suppl 2:130-143. [PMID: 28791703 PMCID: PMC6740332 DOI: 10.1111/jnc.14008] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 02/09/2017] [Accepted: 02/22/2017] [Indexed: 12/23/2022]
Abstract
Abstinence from chronic use of addictive drugs triggers an aversive withdrawal syndrome that compels relapse and deters abstinence. Many features of this syndrome are common across multiple drugs, involving both affective and physical symptoms. Some of the network signaling underlying withdrawal symptoms overlaps with activity that is associated with aversive mood states, including anxiety and depression. Given these shared features, it is not surprising that a particular circuit, the dorsal diencephalic conduction system, and the medial habenula (MHb) and interpeduncular nucleus (IPN), in particular, have been identified as critical to the emergence of aversive states that arise both as a result and, independently, of drug addiction. As the features of this circuit continue to be characterized, the MHb-IPN axis is emerging as a viable target for therapeutics to aid in the treatment of addiction to multiple drugs of abuse as well as mood-associated disorders. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
Collapse
Affiliation(s)
- Ian McLaughlin
- Department of Psychiatry, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Department Neuroscience Graduate Group, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - John A. Dani
- Department Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Mariella De Biasi
- Department of Psychiatry, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Department Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| |
Collapse
|
14
|
González-Rodríguez S, Quadir MA, Gupta S, Walker KA, Zhang X, Spahn V, Labuz D, Rodriguez-Gaztelumendi A, Schmelz M, Joseph J, Parr MK, Machelska H, Haag R, Stein C. Polyglycerol-opioid conjugate produces analgesia devoid of side effects. eLife 2017; 6:e27081. [PMID: 28673386 DOI: 10.7554/elife.2708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/15/2017] [Indexed: 05/27/2023] Open
Abstract
Novel painkillers are urgently needed. The activation of opioid receptors in peripheral inflamed tissue can reduce pain without central adverse effects such as sedation, apnoea, or addiction. Here, we use an unprecedented strategy and report the synthesis and analgesic efficacy of the standard opioid morphine covalently attached to hyperbranched polyglycerol (PG-M) by a cleavable linker. With its high-molecular weight and hydrophilicity, this conjugate is designed to selectively release morphine in injured tissue and to prevent blood-brain barrier permeation. In contrast to conventional morphine, intravenous PG-M exclusively activated peripheral opioid receptors to produce analgesia in inflamed rat paws without major side effects such as sedation or constipation. Concentrations of morphine in the brain, blood, paw tissue, and in vitro confirmed the selective release of morphine in the inflamed milieu. Thus, PG-M may serve as prototype of a peripherally restricted opioid formulation designed to forego central and intestinal side effects.
Collapse
Affiliation(s)
- Sara González-Rodríguez
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany
- Helmholtz Virtual Institute Multifunctional Biomaterials for Medicine, Teltow, Germany
| | - Mohiuddin A Quadir
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Shilpi Gupta
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Karolina A Walker
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Xuejiao Zhang
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Viola Spahn
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany
| | - Dominika Labuz
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany
| | - Antonio Rodriguez-Gaztelumendi
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany
| | - Martin Schmelz
- Department of Anesthesiology, Medical Faculty Mannheim, Universität Heidelberg, Heidelberg, Germany
| | - Jan Joseph
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Maria K Parr
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Halina Machelska
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany
- Helmholtz Virtual Institute Multifunctional Biomaterials for Medicine, Teltow, Germany
| | - Rainer Haag
- Helmholtz Virtual Institute Multifunctional Biomaterials for Medicine, Teltow, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Christoph Stein
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany
- Helmholtz Virtual Institute Multifunctional Biomaterials for Medicine, Teltow, Germany
| |
Collapse
|
15
|
González-Rodríguez S, Quadir MA, Gupta S, Walker KA, Zhang X, Spahn V, Labuz D, Rodriguez-Gaztelumendi A, Schmelz M, Joseph J, Parr MK, Machelska H, Haag R, Stein C. Polyglycerol-opioid conjugate produces analgesia devoid of side effects. eLife 2017; 6. [PMID: 28673386 PMCID: PMC5496737 DOI: 10.7554/elife.27081] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/15/2017] [Indexed: 01/01/2023] Open
Abstract
Novel painkillers are urgently needed. The activation of opioid receptors in peripheral inflamed tissue can reduce pain without central adverse effects such as sedation, apnoea, or addiction. Here, we use an unprecedented strategy and report the synthesis and analgesic efficacy of the standard opioid morphine covalently attached to hyperbranched polyglycerol (PG-M) by a cleavable linker. With its high-molecular weight and hydrophilicity, this conjugate is designed to selectively release morphine in injured tissue and to prevent blood-brain barrier permeation. In contrast to conventional morphine, intravenous PG-M exclusively activated peripheral opioid receptors to produce analgesia in inflamed rat paws without major side effects such as sedation or constipation. Concentrations of morphine in the brain, blood, paw tissue, and in vitro confirmed the selective release of morphine in the inflamed milieu. Thus, PG-M may serve as prototype of a peripherally restricted opioid formulation designed to forego central and intestinal side effects.
Collapse
Affiliation(s)
- Sara González-Rodríguez
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany.,Helmholtz Virtual Institute Multifunctional Biomaterials for Medicine, Teltow, Germany
| | - Mohiuddin A Quadir
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Shilpi Gupta
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Karolina A Walker
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Xuejiao Zhang
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Viola Spahn
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany
| | - Dominika Labuz
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany
| | - Antonio Rodriguez-Gaztelumendi
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany
| | - Martin Schmelz
- Department of Anesthesiology, Medical Faculty Mannheim, Universität Heidelberg, Heidelberg, Germany
| | - Jan Joseph
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Maria K Parr
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Halina Machelska
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany.,Helmholtz Virtual Institute Multifunctional Biomaterials for Medicine, Teltow, Germany
| | - Rainer Haag
- Helmholtz Virtual Institute Multifunctional Biomaterials for Medicine, Teltow, Germany.,Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Christoph Stein
- Department of Anesthesiology and Critical Care Medicine, Charité Campus Benjamin Franklin, Freie Universität Berlin, Berlin, Germany.,Helmholtz Virtual Institute Multifunctional Biomaterials for Medicine, Teltow, Germany
| |
Collapse
|
16
|
Bakhtazad A, Vousooghi N, Garmabi B, Zarrindast MR. Evaluation of the CART peptide expression in morphine sensitization in male rats. Eur J Pharmacol 2017; 802:52-59. [PMID: 28238767 DOI: 10.1016/j.ejphar.2017.02.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 02/20/2017] [Accepted: 02/22/2017] [Indexed: 11/24/2022]
Abstract
The importance of Cocaine- and amphetamine-regulated transcript (CART) peptide in reinforcing effects of addictive drugs specially alcohol and psychostimulants has been stablished. Involvement of CART peptide in rewarding effects of opioids in brain has recently been reported. Here we have studied the expression of CART mRNA and peptide in the reward pathway in morphine-induced sensitization phenomenon and also evaluated the peptide level fluctuations in CSF and plasma. Male Wistar rats received 7-day morphine injection (20mg/kg) and then after a 7-day washout period, a challenge dose of 10mg/kg morphine was administered and locomotor activity and oral stereotypical behaviors were recorded. Besides, the expression level of CART mRNA and peptide in four important areas of the mesocorticolimbic reward pathway including nucleus accumbens, striatum, prefrontal cortex, and hippocampus were measured by real-time PCR and western blotting, respectively. The level of the peptide in CSF and plasma was measured by Elisa method. The expression level of CART mRNA and protein in brain regions and also the peptide level in CSF and plasma were significantly down-regulated after 7-day morphine administration. These reduced levels returned to nearly normal rates after 7-day wash-out period. Administration of morphine challenge dose led to significant upregulation of CART gene expression (both mRNA and peptide) in the brain, and elevation of peptide level in CSF and plasma in morphine-sensitized rats. It can be concluded that CART is released in the framework of reward pathway and may serve as an important neurotransmitter in the process of morphine dependence and sensitization.
Collapse
Affiliation(s)
- Atefeh Bakhtazad
- Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Nasim Vousooghi
- Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Genetics Laboratory, Iranian National Center for Addiction Studies (INCAS), Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran; Research Center for Cognitive and Behavioral Sciences, Tehran University of Medical Sciences, Tehran, Iran
| | - Behzad Garmabi
- Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Zarrindast
- Genetics Laboratory, Iranian National Center for Addiction Studies (INCAS), Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Department of Cognitive Neuroscience, Institute for Cognitive Science Studies, Tehran, Iran; Genomics Center, School of Advanced Sciences, Tehran Medical Branch, Islamic Azad University, Tehran, Iran; School of Cognitive Sciences, Institute for Studies in Theoretical Physics and Mathematics, Tehran, Iran.
| |
Collapse
|
17
|
Abstract
This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.
Collapse
Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, United States.
| |
Collapse
|
18
|
Zhang G, Wu X, Zhang YM, Liu H, Jiang Q, Pang G, Tao X, Dong L, Stackman RW. Activation of serotonin 5-HT(2C) receptor suppresses behavioral sensitization and naloxone-precipitated withdrawal symptoms in morphine-dependent mice. Neuropharmacology 2015; 101:246-54. [PMID: 26432939 DOI: 10.1016/j.neuropharm.2015.09.031] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 09/27/2015] [Accepted: 09/28/2015] [Indexed: 01/24/2023]
Abstract
Opioid abuse and dependence have evolved into an international epidemic as a significant clinical and societal problem with devastating consequences. Repeated exposure to the opioid, for example morphine, can induce profound, long-lasting behavioral sensitization and physical dependence, which are thought to reflect neuroplasticity in neural circuitry. Central serotonin (5-HT) neurotransmission participates in the development of dependence on and the expression of withdrawal from morphine. Serotonin 5-HT(2C) receptor (5-HT(2C)R) agonists suppress psychostimulant nicotine or cocaine-induced behavioral sensitization and drug-seeking behavior; however, the impact of 5-HT(2C)R agonists on behaviors relevant to opioid abuse and dependence has not been reported. In the present study, the effects of 5-HT(2C)R activation on the behavioral sensitization and naloxone-precipitated withdrawal symptoms were examined in mice underwent repeated exposure to morphine. Male mice received morphine (10 mg/kg, s.c.) to develop behavioral sensitization. Lorcaserin, a 5-HT(2C)R agonist, prevented the induction and expression, but not the development, of morphine-induced behavioral sensitization. Another cohort of mice received increasing doses of morphine over a 7-day period to induce morphine-dependence. Pretreatment of lorcaserin, or the positive control clonidine (an alpha 2-adrenoceptor agonist), ameliorated the naloxone-precipitated withdrawal symptoms. SB 242084, a selective 5-HT(2C)R antagonist, prevented the lorcaserin-mediated suppression of behavioral sensitization and withdrawal. Chronic morphine treatment was associated with an increase in the expression of 5-HT(2C)R protein in the ventral tegmental area, locus coeruleus and nucleus accumbens. These findings suggest that 5-HT(2C)R can modulate behavioral sensitization and withdrawal in morphine-dependent mice, and the activation of 5-HT(2C)R may represent a new avenue for the treatment of opioid addiction.
Collapse
Affiliation(s)
- Gongliang Zhang
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China; Life Science Initiative, Charles E. Schmidt College of Science, Florida Atlantic University, 5353 Parkside Drive, Jupiter, FL 33458, USA.
| | - Xian Wu
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China
| | - Yong-Mei Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, College of Anesthesiology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China
| | - Huan Liu
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China
| | - Qin Jiang
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China
| | - Gang Pang
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China
| | - Xinrong Tao
- College of Medicine, Anhui University of Science & Technology, 25 Dongshan Middle Road, Huainan, Anhui 232001, China
| | - Liuyi Dong
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China
| | - Robert W Stackman
- Life Science Initiative, Charles E. Schmidt College of Science, Florida Atlantic University, 5353 Parkside Drive, Jupiter, FL 33458, USA.
| |
Collapse
|
19
|
Craig MM, Bajic D. Long-term behavioral effects in a rat model of prolonged postnatal morphine exposure. Behav Neurosci 2015; 129:643-55. [PMID: 26214209 PMCID: PMC4586394 DOI: 10.1037/bne0000081] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Prolonged morphine treatment in neonatal pediatric populations is associated with a high incidence of opioid tolerance and dependence. Despite the clinical relevance of this problem, our knowledge of long-term consequences is sparse. The main objective of this study was to investigate whether prolonged morphine administration in a neonatal rat is associated with long-term behavioral changes in adulthood. Newborn animals received either morphine (10 mg/kg) or equal volume of saline subcutaneously twice daily for the first 2 weeks of life. Morphine-treated animals underwent 10 days of morphine weaning to reduce the potential for observable physical signs of withdrawal. Animals were subjected to nonstressful testing (locomotor activity recording and a novel-object recognition test) at a young age (Postnatal Days [PDs] 27-31) or later in adulthood (PDs 55-56), as well as stressful testing (calibrated forceps test, hot plate test, and forced swim test) only in adulthood. Analysis revealed that prolonged neonatal morphine exposure resulted in decreased thermal but not mechanical threshold. Importantly, no differences were found for total locomotor activity (proxy of drug reward/reinforcement behavior), individual forced swim test behaviors (proxy of affective processing), or novel-object recognition test. Performance on the novel-object recognition test was compromised in the morphine-treated group at the young age, but the effect disappeared in adulthood. These novel results provide insight into the long-term consequences of opioid treatment during an early developmental period and suggest long-term neuroplastic differences in sensory processing related to thermal stimuli.
Collapse
Affiliation(s)
- Michael M. Craig
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, 300 Longwood Ave., Boston, MA, USA
| | - Dusica Bajic
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, 300 Longwood Ave., Boston, MA, USA
- Department of Anaesthesia, Harvard Medical School, 25 Shattuck St., Boston, MA, USA
| |
Collapse
|