1
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Lubejko ST, Livrizzi G, Buczynski SA, Patel J, Yung JC, Yaksh TL, Banghart MR. Inputs to the locus coeruleus from the periaqueductal gray and rostroventral medulla shape opioid-mediated descending pain modulation. SCIENCE ADVANCES 2024; 10:eadj9581. [PMID: 38669335 PMCID: PMC11051679 DOI: 10.1126/sciadv.adj9581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 03/26/2024] [Indexed: 04/28/2024]
Abstract
The supraspinal descending pain modulatory system (DPMS) shapes pain perception via monoaminergic modulation of sensory information in the spinal cord. However, the role and synaptic mechanisms of descending noradrenergic signaling remain unclear. Here, we establish that noradrenergic neurons of the locus coeruleus (LC) are essential for supraspinal opioid antinociception. While much previous work has emphasized the role of descending serotonergic pathways, we find that opioid antinociception is primarily driven by excitatory output from the ventrolateral periaqueductal gray (vlPAG) to the LC. Furthermore, we identify a previously unknown opioid-sensitive inhibitory input from the rostroventromedial medulla (RVM), the suppression of which disinhibits LC neurons to drive spinal noradrenergic antinociception. We describe pain-related activity throughout this circuit and report the presence of prominent bifurcating outputs from the vlPAG to the LC and the RVM. Our findings substantially revise current models of the DPMS and establish a supraspinal antinociceptive pathway that may contribute to multiple forms of descending pain modulation.
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Affiliation(s)
- Susan T. Lubejko
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Giulia Livrizzi
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Biological Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stanley A. Buczynski
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Chemistry and Biochemistry Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Janki Patel
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jean C. Yung
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Tony L. Yaksh
- Departments of Anesthesiology and Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Matthew R. Banghart
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
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2
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McDevitt DS, Wade QW, McKendrick GE, Nelsen J, Starostina M, Tran N, Blendy JA, Graziane NM. The Paraventricular Thalamic Nucleus and Its Projections in Regulating Reward and Context Associations. eNeuro 2024; 11:ENEURO.0524-23.2024. [PMID: 38351131 PMCID: PMC10883411 DOI: 10.1523/eneuro.0524-23.2024] [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: 12/11/2023] [Revised: 01/23/2024] [Accepted: 01/23/2024] [Indexed: 02/17/2024] Open
Abstract
The paraventricular thalamic nucleus (PVT) is a brain region that mediates aversive and reward-related behaviors as shown in animals exposed to fear conditioning, natural rewards, or drugs of abuse. However, it is unknown whether manipulations of the PVT, in the absence of external factors or stimuli (e.g., fear, natural rewards, or drugs of abuse), are sufficient to drive reward-related behaviors. Additionally, it is unknown whether drugs of abuse administered directly into the PVT are sufficient to drive reward-related behaviors. Here, using behavioral as well as pathway and cell-type specific approaches, we manipulate PVT activity as well as the PVT-to-nucleus accumbens shell (NAcSh) neurocircuit to explore reward phenotypes. First, we show that bath perfusion of morphine (10 µM) caused hyperpolarization of the resting membrane potential, increased rheobase, and decreased intrinsic membrane excitability in PVT neurons that project to the NAcSh. Additionally, we found that direct injections of morphine (50 ng) in the PVT of mice were sufficient to generate conditioned place preference (CPP) for the morphine-paired chamber. Mimicking the inhibitory effect of morphine, we employed a chemogenetic approach to inhibit PVT neurons that projected to the NAcSh and found that pairing the inhibition of these PVT neurons with a specific context evoked the acquisition of CPP. Lastly, using brain slice electrophysiology, we found that bath-perfused morphine (10 µM) significantly reduced PVT excitatory synaptic transmission on both dopamine D1 and D2 receptor-expressing medium spiny neurons in the NAcSh, but that inhibiting PVT afferents in the NAcSh was not sufficient to evoke CPP.
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Affiliation(s)
- Dillon S McDevitt
- Neuroscience Program, Penn State College of Medicine, Hershey, Pennsylvania 17033
| | - Quinn W Wade
- Department of Anesthesiology and Perioperative Medicine, Penn State College of Medicine, Hershey, Pennsylvania 17033
| | - Greer E McKendrick
- Neuroscience Program, Penn State College of Medicine, Hershey, Pennsylvania 17033
| | - Jacob Nelsen
- Doctor of Medicine Program, Penn State College of Medicine, Hershey, Pennsylvania 17033
| | - Mariya Starostina
- Doctor of Medicine Program, Penn State College of Medicine, Hershey, Pennsylvania 17033
| | - Nam Tran
- Doctor of Medicine Program, Penn State College of Medicine, Hershey, Pennsylvania 17033
| | - Julie A Blendy
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Nicholas M Graziane
- Departments of Anesthesiology and Perioperative Medicine and Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania 17033
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3
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McClain SP, Ma X, Johnson DA, Johnson CA, Layden AE, Yung JC, Lubejko ST, Livrizzi G, He XJ, Zhou J, Chang-Weinberg J, Ventriglia E, Rizzo A, Levinstein M, Gomez JL, Bonaventura J, Michaelides M, Banghart MR. In vivo photopharmacology with light-activated opioid drugs. Neuron 2023; 111:3926-3940.e10. [PMID: 37848025 PMCID: PMC11188017 DOI: 10.1016/j.neuron.2023.09.017] [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: 11/16/2022] [Revised: 08/02/2023] [Accepted: 09/14/2023] [Indexed: 10/19/2023]
Abstract
Traditional methods for site-specific drug delivery in the brain are slow, invasive, and difficult to interface with recordings of neural activity. Here, we demonstrate the feasibility and experimental advantages of in vivo photopharmacology using "caged" opioid drugs that are activated in the brain with light after systemic administration in an inactive form. To enable bidirectional manipulations of endogenous opioid receptors in vivo, we developed photoactivatable oxymorphone (PhOX) and photoactivatable naloxone (PhNX), photoactivatable variants of the mu opioid receptor agonist oxymorphone and the antagonist naloxone. Photoactivation of PhOX in multiple brain areas produced local changes in receptor occupancy, brain metabolic activity, neuronal calcium activity, neurochemical signaling, and multiple pain- and reward-related behaviors. Combining PhOX photoactivation with optical recording of extracellular dopamine revealed adaptations in the opioid sensitivity of mesolimbic dopamine circuitry in response to chronic morphine administration. This work establishes a general experimental framework for using in vivo photopharmacology to study the neural basis of drug action.
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Affiliation(s)
- Shannan P McClain
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Xiang Ma
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Desiree A Johnson
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Caroline A Johnson
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Aryanna E Layden
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Jean C Yung
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Susan T Lubejko
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Giulia Livrizzi
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Biological Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - X Jenny He
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Biological Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Jingjing Zhou
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Janie Chang-Weinberg
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Emilya Ventriglia
- Biobehavioral Imaging and Molecular, Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Arianna Rizzo
- Departament de Patologia i Terapèutica Experimental, Institut de Neurociències, Universitat de Barcelona, L'Hospitalet de Llobregat 08907, Catalonia, Spain; Neuropharmacology and Pain Group, Neuroscience Program, Institut d'Investigació Biomèdica de Bellvitge, IDIBELL, L'Hospitalet de Llobregat 08907, Catalonia, Spain
| | - Marjorie Levinstein
- Biobehavioral Imaging and Molecular, Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Juan L Gomez
- Biobehavioral Imaging and Molecular, Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Jordi Bonaventura
- Departament de Patologia i Terapèutica Experimental, Institut de Neurociències, Universitat de Barcelona, L'Hospitalet de Llobregat 08907, Catalonia, Spain; Neuropharmacology and Pain Group, Neuroscience Program, Institut d'Investigació Biomèdica de Bellvitge, IDIBELL, L'Hospitalet de Llobregat 08907, Catalonia, Spain
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular, Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Matthew R Banghart
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA.
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4
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Cahill MK, Perez YR, Larpthaveesarp A, Etchenique R, Poskanzer KE. A Photoactivatable Norepinephrine for Probing Adrenergic Neural Circuits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.13.566764. [PMID: 38014204 PMCID: PMC10680792 DOI: 10.1101/2023.11.13.566764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Norepinephrine (NE) is a critical neuromodulator that mediates a wide range of behavior and neurophysiology, including attention, arousal, plasticity, and memory consolidation. A major source of NE is the brainstem nucleus the locus coeruleus (LC), which sends widespread projections throughout the central nervous system (CNS). Efforts to dissect this complex noradrenergic circuitry have driven the development of many tools that detect endogenous NE or modulate widespread NE release via LC activation and inhibition. While these tools have enabled research that elucidates physiological roles of NE, additional tools to probe these circuits with a higher degree of spatial precision could enable a finer delineation of function. Here, we describe the synthesis and chemical properties of a photo-activatable NE, [Ru(bpy) 2 (PMe 3 )(NE)]PF 6 (RuBi-NE). We validate the one-photon (1P) release of NE using whole-cell patch clamp electrophysiology in acute mouse brain slices containing the LC. We show that a 10 ms pulse of blue light, in the presence of RuBi-NE, briefly modulates the firing rate of LC neurons via α-2 adrenergic receptors. The development of a photo-activatable NE that can be released with light in the visible spectrum provides a new tool for fine-grained mapping of complex noradrenergic circuits, as well as the ability to probe how NE acts on non-neuronal cells in the CNS.
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5
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Norris MR, Kuo CC, Kim JR, Dunn SS, Borges G, Thang LV, McCall JG. Endogenous opioids gate the locus coeruleus pain generator. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.20.562785. [PMID: 37961541 PMCID: PMC10634678 DOI: 10.1101/2023.10.20.562785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The locus coeruleus (LC) plays a paradoxical role in chronic pain. Although largely known as a potent source of endogenous analgesia, increasing evidence suggests injury can transform the LC into a chronic pain generator. We sought to clarify the role of this system in pain. Here, we show optogenetic inhibition of LC activity is acutely antinociceptive. Following long-term spared nerve injury, the same LC inhibition is analgesic - further supporting its pain generator function. To identify inhibitory substrates that may naturally serve this function, we turned to endogenous LC mu opioid receptors (LC-MOR). These receptors provide powerful LC inhibition and exogenous activation of LC-MOR is antinociceptive. We therefore hypothesized that endogenous LC-MOR-mediated inhibition is critical to how the LC modulates pain. Using cell type-selective conditional knockout and rescue of LC-MOR receptor signaling, we show these receptors bidirectionally regulate thermal and mechanical hyperalgesia - providing a functional gate on the LC pain generator.
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Affiliation(s)
- Makenzie R. Norris
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, USA; Department of Pharmaceutical and Administrative Sciences, St. Louis College of Pharmacy, St. Louis, MO, USA; Center for Clinical Pharmacology, St. Louis College of Pharmacy and Washington University School of Medicine, St. Louis, MO, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO, USA
- Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Chao-Cheng Kuo
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, USA; Department of Pharmaceutical and Administrative Sciences, St. Louis College of Pharmacy, St. Louis, MO, USA; Center for Clinical Pharmacology, St. Louis College of Pharmacy and Washington University School of Medicine, St. Louis, MO, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO, USA
| | - Jenny R. Kim
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, USA; Department of Pharmaceutical and Administrative Sciences, St. Louis College of Pharmacy, St. Louis, MO, USA; Center for Clinical Pharmacology, St. Louis College of Pharmacy and Washington University School of Medicine, St. Louis, MO, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO, USA
| | - Samantha S. Dunn
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, USA; Department of Pharmaceutical and Administrative Sciences, St. Louis College of Pharmacy, St. Louis, MO, USA; Center for Clinical Pharmacology, St. Louis College of Pharmacy and Washington University School of Medicine, St. Louis, MO, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO, USA
| | - Gustavo Borges
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, USA; Department of Pharmaceutical and Administrative Sciences, St. Louis College of Pharmacy, St. Louis, MO, USA; Center for Clinical Pharmacology, St. Louis College of Pharmacy and Washington University School of Medicine, St. Louis, MO, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO, USA
| | - Loc V. Thang
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, USA; Department of Pharmaceutical and Administrative Sciences, St. Louis College of Pharmacy, St. Louis, MO, USA; Center for Clinical Pharmacology, St. Louis College of Pharmacy and Washington University School of Medicine, St. Louis, MO, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO, USA
| | - Jordan G. McCall
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, USA; Department of Pharmaceutical and Administrative Sciences, St. Louis College of Pharmacy, St. Louis, MO, USA; Center for Clinical Pharmacology, St. Louis College of Pharmacy and Washington University School of Medicine, St. Louis, MO, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO, USA
- Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO, USA
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6
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Lubejko ST, Livrizzi G, Patel J, Yung JC, Yaksh TL, Banghart MR. Inputs to the locus coeruleus from the periaqueductal gray and rostroventral medulla shape opioid-mediated descending pain modulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.10.561768. [PMID: 37873091 PMCID: PMC10592708 DOI: 10.1101/2023.10.10.561768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The supraspinal descending pain modulatory system (DPMS) shapes pain perception via monoaminergic modulation of sensory information in the spinal cord. However, the role and synaptic mechanisms of descending noradrenergic signaling remain unclear. Here, we establish that noradrenergic neurons of the locus coeruleus (LC) are essential for supraspinal opioid antinociception. Unexpectedly, given prior emphasis on descending serotonergic pathways, we find that opioid antinociception is primarily driven by excitatory output from the ventrolateral periaqueductal gray (vlPAG) to the LC. Furthermore, we identify a previously unknown opioid-sensitive inhibitory input from the rostroventromedial medulla (RVM), the suppression of which disinhibits LC neurons to drive spinal noradrenergic antinociception. We also report the presence of prominent bifurcating outputs from the vlPAG to the LC and the RVM. Our findings significantly revise current models of the DPMS and establish a novel supraspinal antinociceptive pathway that may contribute to multiple forms of descending pain modulation.
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Affiliation(s)
- Susan T. Lubejko
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Giulia Livrizzi
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
- Biological Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Janki Patel
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Jean C. Yung
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Tony L. Yaksh
- Departments of Anesthesiology and Pharmacology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Matthew R. Banghart
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
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7
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Kelly E, Sutcliffe K, Cavallo D, Ramos-Gonzalez N, Alhosan N, Henderson G. The anomalous pharmacology of fentanyl. Br J Pharmacol 2023; 180:797-812. [PMID: 34030211 DOI: 10.1111/bph.15573] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/27/2021] [Accepted: 05/12/2021] [Indexed: 11/26/2022] Open
Abstract
Fentanyl is a key therapeutic, used in anaesthesia and pain management. It is also increasingly used illicitly and is responsible for a large and growing number of opioid overdose deaths, especially in North America. A number of factors have been suggested to contribute to fentanyl's lethality, including rapid onset of action, in vivo potency, ligand bias, induction of muscle rigidity and reduced sensitivity to reversal by naloxone. Some of these factors can be considered to represent 'anomalous' pharmacological properties of fentanyl when compared with prototypical opioid agonists such as morphine. In this review, we examine the nature of fentanyl's 'anomalous' properties, to determine whether there is really a pharmacological basis to support the existence of such properties, and also discuss whether such properties are likely to contribute to overdose deaths involving fentanyls. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.
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Affiliation(s)
- Eamonn Kelly
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Katy Sutcliffe
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Damiana Cavallo
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | | | - Norah Alhosan
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Graeme Henderson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
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8
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Farahani F, Pachenari N, Mohammad Ahmadi-Soleimani S, Azizi H, Semnanian S. Acute morphine injection persistently affects the electrophysiological characteristics of rat locus coeruleus neurons. Neurosci Lett 2023; 795:137048. [PMID: 36603738 DOI: 10.1016/j.neulet.2023.137048] [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: 12/08/2022] [Revised: 12/27/2022] [Accepted: 01/01/2023] [Indexed: 01/03/2023]
Abstract
Administration of morphine is associated with critical complications in clinic which primarily includes the development of dependence and tolerance even following a single dose (acute) exposure. Behavioral and electrophysiological studies support the significant role of locus coeruleus (LC) neurons in tolerance and dependence following chronic morphine exposure. The current study was designed to explore the electrophysiological properties of the LC neurons following acute morphine exposure. In-vitro whole-cell patch-clamp recordings were performed in LC neurons 24 h after intraperitoneal morphine injection. Acute morphine injection significantly decreased the spontaneous firing rate of LC neurons, the rising and decay slopes of action potentials, and consequently increased the action potential duration. In addition, morphine treatment did not alter the rheobase current and first spike latency while affected the inhibitory postsynaptic currents elicited in response to orexin-A. In fact, single morphine exposure could inhibit the disinhibitory effect of orexin-A on LC neurons.
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Affiliation(s)
- Fatemeh Farahani
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Narges Pachenari
- School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
| | - S Mohammad Ahmadi-Soleimani
- Deparment of Physiology, School of Paramedical Sciences, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran
| | - Hossein Azizi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
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9
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Kumar GA, Puthenveedu MA. Diversity and specificity in location-based signaling outputs of neuronal GPCRs. Curr Opin Neurobiol 2022; 76:102601. [DOI: 10.1016/j.conb.2022.102601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/27/2022] [Accepted: 06/01/2022] [Indexed: 11/30/2022]
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10
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Lubejko ST, Graham RD, Livrizzi G, Schaefer R, Banghart MR, Creed MC. The role of endogenous opioid neuropeptides in neurostimulation-driven analgesia. Front Syst Neurosci 2022; 16:1044686. [PMID: 36591324 PMCID: PMC9794630 DOI: 10.3389/fnsys.2022.1044686] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/18/2022] [Indexed: 12/15/2022] Open
Abstract
Due to the prevalence of chronic pain worldwide, there is an urgent need to improve pain management strategies. While opioid drugs have long been used to treat chronic pain, their use is severely limited by adverse effects and abuse liability. Neurostimulation techniques have emerged as a promising option for chronic pain that is refractory to other treatments. While different neurostimulation strategies have been applied to many neural structures implicated in pain processing, there is variability in efficacy between patients, underscoring the need to optimize neurostimulation techniques for use in pain management. This optimization requires a deeper understanding of the mechanisms underlying neurostimulation-induced pain relief. Here, we discuss the most commonly used neurostimulation techniques for treating chronic pain. We present evidence that neurostimulation-induced analgesia is in part driven by the release of endogenous opioids and that this endogenous opioid release is a common endpoint between different methods of neurostimulation. Finally, we introduce technological and clinical innovations that are being explored to optimize neurostimulation techniques for the treatment of pain, including multidisciplinary efforts between neuroscience research and clinical treatment that may refine the efficacy of neurostimulation based on its underlying mechanisms.
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Affiliation(s)
- Susan T. Lubejko
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Robert D. Graham
- Department of Anesthesiology, Pain Center, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Giulia Livrizzi
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Robert Schaefer
- Department of Anesthesiology, Pain Center, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Matthew R. Banghart
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
- *Correspondence: Matthew R. Banghart,
| | - Meaghan C. Creed
- Department of Anesthesiology, Pain Center, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, United States
- Department of Psychiatry, Washington University in St. Louis, St. Louis, MO, United States
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States
- Meaghan C. Creed,
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11
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He XJ, Patel J, Weiss CE, Ma X, Bloodgood BL, Banghart MR. Convergent, functionally independent signaling by mu and delta opioid receptors in hippocampal parvalbumin interneurons. eLife 2021; 10:69746. [PMID: 34787079 PMCID: PMC8716102 DOI: 10.7554/elife.69746] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/16/2021] [Indexed: 11/13/2022] Open
Abstract
Functional interactions between G protein-coupled receptors are poised to enhance neuronal sensitivity to neuromodulators and therapeutic drugs. Mu and Delta opioid receptors (MORs and DORs) can interact when overexpressed in the same cells, but whether co-expression of endogenous MORs and DORs in neurons leads to functional interactions is unclear. Here, in mice, we show that both MORs and DORs inhibit parvalbumin-expressing basket cells (PV-BCs) in hippocampal CA1 through partially occlusive signaling pathways that terminate on somato-dendritic potassium channels and presynaptic calcium channels. Using photoactivatable opioid neuropeptides, we find that DORs dominate the response to enkephalin in terms of both ligand-sensitivity and kinetics, which may be due to relatively low expression levels of MOR. Opioid-activated potassium channels do not show heterologous desensitization, indicating that MORs and DORs signal independently. In a direct test for heteromeric functional interactions, the DOR antagonist TIPP-Psi does not alter the kinetics or potency of either the potassium channel or synaptic responses to photorelease of the MOR agonist DAMGO. Thus, aside from largely redundant and convergent signaling, MORs and DORs do not functionally interact in PV-BCs in a way that impacts somato-dendritic potassium currents or synaptic transmission. These findings imply that crosstalk between MORs and DORs, either in the form of physical interactions or synergistic intracellular signaling, is not a preordained outcome of co-expression in neurons.
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Affiliation(s)
- Xinyi Jenny He
- Biological Sciences, University of California San Diego, La Jolla, United States
| | - Janki Patel
- University of California San Diego, San Diego, United States
| | - Connor E Weiss
- University of California San Diego, San Diego, United States
| | - Xiang Ma
- University of California San Diego, San Diego, United States
| | - Brenda L Bloodgood
- Biological Sciences, University of California San Diego, La Jolla, United States
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12
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Huang D, Grady FS, Peltekian L, Laing JJ, Geerling JC. Efferent projections of CGRP/Calca-expressing parabrachial neurons in mice. J Comp Neurol 2021; 529:2911-2957. [PMID: 33715169 DOI: 10.1002/cne.25136] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 03/07/2021] [Accepted: 03/08/2021] [Indexed: 12/19/2022]
Abstract
The parabrachial nucleus (PB) is composed of glutamatergic neurons at the midbrain-hindbrain junction. These neurons form many subpopulations, one of which expresses Calca, which encodes the neuropeptide calcitonin gene-related peptide (CGRP). This Calca-expressing subpopulation has been implicated in a variety of homeostatic functions, but the overall distribution of Calca-expressing neurons in this region remains unclear. Also, while previous studies in rats and mice have identified output projections from CGRP-immunoreactive or Calca-expressing neurons, we lack a comprehensive understanding of their efferent projections. We began by identifying neurons with Calca mRNA and CGRP immunoreactivity in and around the PB, including populations in the locus coeruleus and motor trigeminal nucleus. Calca-expressing neurons in the PB prominently express the mu opioid receptor (Oprm1) and are distinct from neighboring neurons that express Foxp2 and Pdyn. Next, we used Cre-dependent anterograde tracing with synaptophysin-mCherry to map the efferent projections of these neurons. Calca-expressing PB neurons heavily target subregions of the amygdala, bed nucleus of the stria terminalis, basal forebrain, thalamic intralaminar and ventral posterior parvicellular nuclei, and hindbrain, in different patterns depending on the injection site location within the PB region. Retrograde axonal tracing revealed that the previously unreported hindbrain projections arise from a rostral-ventral subset of CGRP/Calca neurons. Finally, we show that these efferent projections of Calca-expressing neurons are distinct from those of neighboring PB neurons that express Pdyn. This information provides a detailed neuroanatomical framework for interpreting experimental work involving CGRP/Calca-expressing neurons and opioid action in the PB region.
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Affiliation(s)
- Dake Huang
- Department of Neurology, University of Iowa, Iowa, USA
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13
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Robayo Avendaño O, Alvira Botero X, Garzón M. Ultrastructural evidence for mu and delta opioid receptors at noradrenergic dendrites and glial profiles in the cat locus coeruleus. Brain Res 2021; 1762:147443. [PMID: 33745926 DOI: 10.1016/j.brainres.2021.147443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 02/01/2021] [Accepted: 03/13/2021] [Indexed: 11/17/2022]
Abstract
The Locus Coeruleus (LC) is a pontine nucleus involved in many physiological processes, including the control of the sleep/wake cycle (SWC). At cellular level, the LC displays a high density of opioid receptors whose activation decreases the activity of LC noradrenergic neurons. Also, microinjections of morphine administered locally in the LC of the cat produce sleep associated with synchronized brain activity in the electroencephalogram (EEG). Even though much of the research on sleep has been done in the cat, the subcellular location of opioid receptors in the LC and their relationship with LC noradrenergic neurons is not known yet in this species. Therefore, we conducted a study to describe the ultrastructural localization of mu-opioid receptors (MOR), delta-opioid receptors (DOR) and tyrosine hydroxylase (TH) in the cat LC using high resolution electron microscopy double-immunocytochemical detection. MOR and DOR were localized mainly in dendrites (45% and 46% of the total number of profiles respectively), many of which were noradrenergic (35% and 53% for MOR and DOR, respectively). TH immunoreactivity was more frequent in dendrites (65% of the total number of profiles), which mostly also expressed opioid receptors (58% and 73% for MOR and DOR, respectively). Because the distribution of MORs and DORs are similar, it is possible that a substantial sub-population of neurons co-express both receptors, which may facilitate the formation of MOR-DOR heterodimers. Moreover, we found differences in the cat subcellular DOR distribution compared with the rat. This opens the possibility to the existence of diverse mechanisms for opioid modulation of LC activity.
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Affiliation(s)
- Omar Robayo Avendaño
- Universidad Pedagógica y Tecnológica de Colombia. Antiguo Hospital San Rafael, 150001 Tunja, Colombia.
| | - Ximena Alvira Botero
- Universidad Autónoma de Madrid, Calle del Arzobispo Morcillo 4, 28029 Madrid, Spain
| | - Miguel Garzón
- Universidad Autónoma de Madrid, Calle del Arzobispo Morcillo 4, 28029 Madrid, Spain
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14
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Ye L, Orynbayev M, Zhu X, Lim EY, Dereddi RR, Agarwal A, Bergles DE, Bhat MA, Paukert M. Ethanol abolishes vigilance-dependent astroglia network activation in mice by inhibiting norepinephrine release. Nat Commun 2020; 11:6157. [PMID: 33268792 PMCID: PMC7710743 DOI: 10.1038/s41467-020-19475-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 10/16/2020] [Indexed: 12/17/2022] Open
Abstract
Norepinephrine adjusts sensory processing in cortical networks and gates plasticity enabling adaptive behavior. The actions of norepinephrine are profoundly altered by recreational drugs like ethanol, but the consequences of these changes on distinct targets such as astrocytes, which exhibit norepinephrine-dependent Ca2+ elevations during vigilance, are not well understood. Using in vivo two-photon imaging, we show that locomotion-induced Ca2+ elevations in mouse astroglia are profoundly inhibited by ethanol, an effect that can be reversed by enhancing norepinephrine release. Vigilance-dependent astroglial activation is abolished by deletion of α1A-adrenergic receptor from astroglia, indicating that norepinephrine acts directly on these ubiquitous glial cells. Ethanol reduces vigilance-dependent Ca2+ transients in noradrenergic terminals, but has little effect on astroglial responsiveness to norepinephrine, suggesting that ethanol suppresses their activation by inhibiting norepinephrine release. Since abolition of astroglia Ca2+ activation does not affect motor coordination, global suppression of astroglial networks may contribute to the cognitive effects of alcohol intoxication. The effects of norepinephrine on sensory processing in cortical networks are altered by recreational drugs like ethanol. The authors show that ethanol suppresses the activation of astrocytes by inhibiting norepinephrine release which may contribute to the cognitive effects of alcohol intoxication.
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Affiliation(s)
- Liang Ye
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Murat Orynbayev
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Xiangyu Zhu
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Eunice Y Lim
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Ram R Dereddi
- The Chica and Heinz Schaller Research Group, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Amit Agarwal
- The Chica and Heinz Schaller Research Group, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany.,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Dwight E Bergles
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Johns Hopkins Kavli Neuroscience Discovery Institute, Baltimore, MD, USA
| | - Manzoor A Bhat
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Martin Paukert
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA. .,Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
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15
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Gillis A, Kliewer A, Kelly E, Henderson G, Christie MJ, Schulz S, Canals M. Critical Assessment of G Protein-Biased Agonism at the μ-Opioid Receptor. Trends Pharmacol Sci 2020; 41:947-959. [PMID: 33097283 DOI: 10.1016/j.tips.2020.09.009] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 01/14/2023]
Abstract
G protein-biased agonists of the μ-opioid receptor (MOPr) have been proposed as an improved class of opioid analgesics. Recent studies have been unable to reproduce the original experiments in the β-arrestin2-knockout mouse that led to this proposal, and alternative genetic models do not support the G protein-biased MOPr agonist hypothesis. Furthermore, assessment of putatively biased ligands has been confounded by several factors, including assay amplification. As such, the extent to which current lead compounds represent mechanistically novel, extremely G protein-biased agonists is in question, as is the underlying assumption that β-arrestin2 mediates deleterious opioid effects. Addressing these current challenges represents a pressing issue to successfully advance drug development at this receptor and improve upon current opioid analgesics.
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Affiliation(s)
- Alexander Gillis
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
| | - Andrea Kliewer
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany
| | - Eamonn Kelly
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, UK
| | - Graeme Henderson
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, UK
| | - Macdonald J Christie
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia.
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany.
| | - Meritxell Canals
- Division of Physiology, Pharmacology, and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK.
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16
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Jullié D, Gondin AB, von Zastrow M, Canals M. Opioid Pharmacology under the Microscope. Mol Pharmacol 2020; 98:425-432. [PMID: 32198210 DOI: 10.1124/mol.119.119321] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/10/2020] [Indexed: 12/18/2022] Open
Abstract
The powerful analgesic effects of opioid drugs have captivated the interest of physicians and scientists for millennia, and the ability of opioid drugs to produce serious undesired effects has been recognized for a similar period of time (Kieffer and Evans, 2009). Many of these develop progressively with prolonged or repeated drug use and then persist, motivating particular interest in understanding how opioid drugs initiate adaptive or maladaptive modifications in neural function or regulation. Exciting advances have been made over the past several years in elucidating drug-induced changes at molecular, cellular, and physiologic scales of analysis. The present review will highlight some recent cellular studies that we believe bridge across scales and will focus on optical imaging approaches that put opioid drug action "under the microscope." SIGNIFICANCE STATEMENT: Opioid receptors are major pharmacological targets, but their signaling at the cellular level results from a complex interplay between pharmacology, regulation, subcellular localization, and membrane trafficking. This minireview discusses recent advances in understanding the cellular biology of opioid receptors, emphasizing particular topics discussed at the 50th anniversary of the International Narcotics Research Conference. Our goal is to highlight distinct signaling and regulatory properties emerging from the cellular biology of opioid receptors and discuss potential relevance to therapeutics.
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Affiliation(s)
- Damien Jullié
- Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco School of Medicine, San Francisco, California (D.J., M.v.Z.); Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia (A.B.G.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (M.C.); and Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, The Midlands, United Kingdom (M.C.)
| | - Arisbel B Gondin
- Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco School of Medicine, San Francisco, California (D.J., M.v.Z.); Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia (A.B.G.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (M.C.); and Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, The Midlands, United Kingdom (M.C.)
| | - Mark von Zastrow
- Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco School of Medicine, San Francisco, California (D.J., M.v.Z.); Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia (A.B.G.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (M.C.); and Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, The Midlands, United Kingdom (M.C.)
| | - Meritxell Canals
- Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco School of Medicine, San Francisco, California (D.J., M.v.Z.); Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia (A.B.G.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (M.C.); and Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, The Midlands, United Kingdom (M.C.)
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17
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Ruth KS, Day FR, Tyrrell J, Thompson DJ, Wood AR, Mahajan A, Beaumont RN, Wittemans L, Martin S, Busch AS, Erzurumluoglu AM, Hollis B, O'Mara TA, McCarthy MI, Langenberg C, Easton DF, Wareham NJ, Burgess S, Murray A, Ong KK, Frayling TM, Perry JRB. Using human genetics to understand the disease impacts of testosterone in men and women. Nat Med 2020; 26:252-258. [PMID: 32042192 PMCID: PMC7025895 DOI: 10.1038/s41591-020-0751-5] [Citation(s) in RCA: 338] [Impact Index Per Article: 84.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/03/2020] [Indexed: 11/20/2022]
Abstract
Testosterone supplementation is commonly used for its effects on sexual function, bone health and body composition, yet its effects on disease outcomes are unknown. To better understand this, we identified genetic determinants of testosterone levels and related sex hormone traits in 425,097 UK Biobank study participants. Using 2,571 genome-wide significant associations, we demonstrate that the genetic determinants of testosterone levels are substantially different between sexes and that genetically higher testosterone is harmful for metabolic diseases in women but beneficial in men. For example, a genetically determined 1 s.d. higher testosterone increases the risks of type 2 diabetes (odds ratio (OR) = 1.37 (95% confidence interval (95% CI): 1.22-1.53)) and polycystic ovary syndrome (OR = 1.51 (95% CI: 1.33-1.72)) in women, but reduces type 2 diabetes risk in men (OR = 0.86 (95% CI: 0.76-0.98)). We also show adverse effects of higher testosterone on breast and endometrial cancers in women and prostate cancer in men. Our findings provide insights into the disease impacts of testosterone and highlight the importance of sex-specific genetic analyses.
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Affiliation(s)
- Katherine S Ruth
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Felix R Day
- Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Jessica Tyrrell
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Deborah J Thompson
- Centre for Cancer Genetic Epidemiology, University of Cambridge, Cambridge, UK
| | - Andrew R Wood
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Anubha Mahajan
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Robin N Beaumont
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Laura Wittemans
- Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, Cambridge, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Susan Martin
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Alexander S Busch
- Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, Cambridge, UK
- International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health, University of Copenhagen, Copenhagen, Denmark
- Department of Growth and Reproduction, University of Copenhagen, Copenhagen, Denmark
| | - A Mesut Erzurumluoglu
- Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Benjamin Hollis
- Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Tracy A O'Mara
- Department of Genetics, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Mark I McCarthy
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
- Oxford Centre for Diabetes, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
- Genentech, San Francisco, CA, USA
| | - Claudia Langenberg
- Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Douglas F Easton
- Centre for Cancer Genetic Epidemiology, University of Cambridge, Cambridge, UK
| | - Nicholas J Wareham
- Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Stephen Burgess
- MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
- BHF Cardiovascular Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Anna Murray
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Ken K Ong
- Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, Cambridge, UK
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | | | - John R B Perry
- Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, Cambridge, UK.
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18
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Abstract
Whilst the nociceptin/orphanin FQ (N/OFQ) receptor (NOP) has similar intracellular coupling mechanisms to opioid receptors, it has distinct modulatory effects on physiological functions such as pain. These actions range from agonistic to antagonistic interactions with classical opioids within the spinal cord and brain, respectively. Understanding the electrophysiological actions of N/OFQ has been crucial in ascertaining the mechanisms by which these agonistic and antagonistic interactions occur. These similarities and differences between N/OFQ and opioids are due to the relative location of NOP versus opioid receptors on specific neuronal elements within these CNS regions. These mechanisms result in varied cellular actions including postsynaptic modulation of ion channels and presynaptic regulation of neurotransmitter release.
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19
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Andrade Próspero DF, Reis Filho AC, Piauilino CA, Lopes EM, de Sousa DP, de Castro Almeida FR. Effects of isopulegol in acute nociception in mice: Possible involvement of muscarinic receptors, opioid system and l-arginine/NO/cGMP pathway. Chem Biol Interact 2018; 293:55-60. [PMID: 30053451 DOI: 10.1016/j.cbi.2018.07.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/13/2018] [Accepted: 07/23/2018] [Indexed: 02/07/2023]
Abstract
Previous studies have shown that isopulegol has anxiolytic, anticonvulsant, gastro-protective and antioxidant activities in rodents, but until now there are no studies showing activity of isopulegol in animal models of nociception and inflammation. The objective of this study was to evaluate the antinociceptive effect of isopulegol and to propose possible mechanisms involved in its effects observed in mice. Groups of male and female Swiss mice (20-35 g, n = 5-8) were used in this test under the authorization of Ethics Committee on Animal Experimentation (CEEA/UFPI N° 82/2014). In order to evaluate the antinociceptive activity of isopulegol, nociception was induced using formalin test, capsaicin and glutamate in hind paw licking model, followed by the investigation of the involvement of opioid mechanisms, K + ATP channels, muscarinic, L arginine-nitric oxide and cGMP. The oral administration of isopulegol showed antinociceptive effect in both phases of the formalin test at doses from 0.78 to 25 mg/kg (first phase) and 1.56-25 mg/kg (second phase) and also produced significant results before capsaicin test at doses from 1.56 to 12.5 mg/kg and glutamate test at doses from 3.12 to 6.25 mg/kg with a dose-dependent effect. The antinociception activity of isopulegol was inhibited in the presence of naloxone (2 mg / kg, ip), glibenclamide (3 mg/kg, ip), atropine (1 mg/kg, ip), l-arginine (600 mg/kg, ip) and methylene blue (20 mg/kg, ip). The results suggested that acute antinociceptive action of opioid isopulegol seems to be related to the K + ATP channels system, through the involvement of muscarinic receptors, inhibiting nitric oxide and cGMP.
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Affiliation(s)
| | | | | | - Everton Moraes Lopes
- Medicinal Plants Research Center, Federal University of Piauí, Teresina, PI, Brazil
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20
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Llamosas N, Ugedo L, Torrecilla M. Inactivation of GIRK channels weakens the pre- and postsynaptic inhibitory activity in dorsal raphe neurons. Physiol Rep 2018; 5:5/3/e13141. [PMID: 28196855 PMCID: PMC5309581 DOI: 10.14814/phy2.13141] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 12/26/2016] [Accepted: 01/06/2017] [Indexed: 01/17/2023] Open
Abstract
The serotonergic tone of the dorsal raphe (DR) is regulated by 5-HT1A receptors, which negatively control serotonergic activity via the activation of G protein-coupled inwardly rectifying K+ (GIRK) channels. In addition, DR activity is modulated by local GABAergic transmission, which is believed to play a key role in the development of mood-related disorders. Here, we sought to characterize the role of GIRK2 subunit-containing channels on the basal electrophysiological properties of DR neurons and to investigate whether the presynaptic and postsynaptic activities of 5-HT1A, GABAB, and GABAA receptors are affected by Girk2 gene deletion. Whole-cell patch-clamp recordings in brain slices from GIRK2 knockout mice revealed that the GIRK2 subunit contributes to maintenance of the resting membrane potential and to the membrane input resistance of DR neurons. 5-HT1A and GABAB receptor-mediated postsynaptic currents were almost absent in the mutant mice. Spontaneous and evoked GABAA receptor-mediated transmissions were markedly reduced in GIRK2 KO mice, as the frequency and amplitude of spontaneous IPSCs were reduced, the paired-pulse ratio was increased and GABA-induced whole-cell currents were decreased. Similarly, the pharmacological blockade of GIRK channels with tertiapin-Q prevented the 5-HT1A and GABAB receptor-mediated postsynaptic currents and increased the paired-pulse ratio. Finally, deletion of the Girk2 gene also limited the presynaptic inhibition of GABA release exerted by 5-HT1A and GABAB receptors. These results indicate that the properties and inhibitory activity of DR neurons are highly regulated by GIRK2 subunit-containing channels, introducing GIRK channels as potential candidates for studying the pathophysiology and treatment of affective disorders.
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Affiliation(s)
- Nerea Llamosas
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Luisa Ugedo
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Maria Torrecilla
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, Leioa, Spain
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21
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Ferdousi M, Finn DP. Stress-induced modulation of pain: Role of the endogenous opioid system. PROGRESS IN BRAIN RESEARCH 2018; 239:121-177. [DOI: 10.1016/bs.pbr.2018.07.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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22
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Direct Facilitatory Role of Paragigantocellularis Neurons in Opiate Withdrawal-Induced Hyperactivity of Rat Locus Coeruleus Neurons: An In Vitro Study. PLoS One 2015; 10:e0134873. [PMID: 26230639 PMCID: PMC4521852 DOI: 10.1371/journal.pone.0134873] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 07/14/2015] [Indexed: 11/19/2022] Open
Abstract
Studies have shown that following opiate withdrawal, the spontaneous discharge rate of locus coeruleus (LC) neurons remarkably increases. Combination of intrinsic mechanisms with extrinsic excitatory modulations mediates the withdrawal-induced hyperactivity of LC neurons. The nucleus paragigantocellularis (PGi) provides the main excitatory inputs to LC and plays a pivotal role in opiate withdrawal. In the present study the direct facilitatory role of PGi on opiate withdrawal-induced hyperactivity of LC neurons was investigated using a newly developed brain slice, containing both LC and PGi. HRP retrograde neuronal tracing was used to verify the existence of both LC and PGi neurons in the developed slice. The spontaneous discharge rate (SDR), resting membrane potential (RMP) and spontaneous excitatory post-synaptic currents (sEPSCs) were recorded in LC neurons using whole cell patch clamp recording. Results showed that the net SDR and the net RMP of LC neurons in slices containing both LC and PGi neurons are significantly higher than slices lacking intact (uncut) PGi inputs. Also, the frequency of sEPSCs in those LC neurons receiving PGi inputs significantly increased compared to the slices containing no intact PGi inputs. Altogether, our results propose that increase in PGi-mediated excitatory transmission might facilitate the opiate withdrawal-induced hyperactivity of LC neurons.
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23
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Browning KN, Travagli RA. Central nervous system control of gastrointestinal motility and secretion and modulation of gastrointestinal functions. Compr Physiol 2015; 4:1339-68. [PMID: 25428846 DOI: 10.1002/cphy.c130055] [Citation(s) in RCA: 322] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Although the gastrointestinal (GI) tract possesses intrinsic neural plexuses that allow a significant degree of autonomy over GI functions, the central nervous system (CNS) provides extrinsic neural inputs that regulate, modulate, and control these functions. While the intestines are capable of functioning in the absence of extrinsic inputs, the stomach and esophagus are much more dependent upon extrinsic neural inputs, particularly from parasympathetic and sympathetic pathways. The sympathetic nervous system exerts a predominantly inhibitory effect upon GI muscle and provides a tonic inhibitory influence over mucosal secretion while, at the same time, regulates GI blood flow via neurally mediated vasoconstriction. The parasympathetic nervous system, in contrast, exerts both excitatory and inhibitory control over gastric and intestinal tone and motility. Although GI functions are controlled by the autonomic nervous system and occur, by and large, independently of conscious perception, it is clear that the higher CNS centers influence homeostatic control as well as cognitive and behavioral functions. This review will describe the basic neural circuitry of extrinsic inputs to the GI tract as well as the major CNS nuclei that innervate and modulate the activity of these pathways. The role of CNS-centered reflexes in the regulation of GI functions will be discussed as will modulation of these reflexes under both physiological and pathophysiological conditions. Finally, future directions within the field will be discussed in terms of important questions that remain to be resolved and advances in technology that may help provide these answers.
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Affiliation(s)
- Kirsteen N Browning
- Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, Pennsylvania
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Chen YB, Huang FS, Fen B, Yin JB, Wang W, Li YQ. Inhibitory effects of endomorphin-2 on excitatory synaptic transmission and the neuronal excitability of sacral parasympathetic preganglionic neurons in young rats. Front Cell Neurosci 2015; 9:206. [PMID: 26074773 PMCID: PMC4446531 DOI: 10.3389/fncel.2015.00206] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 05/12/2015] [Indexed: 01/23/2023] Open
Abstract
The function of the urinary bladder is partly controlled by parasympathetic preganglionic neurons (PPNs) of the sacral parasympathetic nucleus (SPN). Our recent work demonstrated that endomorphin-2 (EM-2)-immunoreactive (IR) terminals form synapses with μ-opioid receptor (MOR)-expressing PPNs in the rat SPN. Here, we examined the effects of EM-2 on excitatory synaptic transmission and the neuronal excitability of the PPNs in young rats (24–30 days old) using a whole-cell patch-clamp approach. PPNs were identified by retrograde labeling with the fluorescent tracer tetramethylrhodamine-dextran (TMR). EM-2 (3 μM) markedly decreased both the amplitude and the frequency of the spontaneous and miniature excitatory postsynaptic currents (sEPSCs and mEPSCs) of PPNs. EM-2 not only decreased the resting membrane potentials (RMPs) in 61.1% of the examined PPNs with half-maximal response at the concentration of 0.282 μM, but also increased the rheobase current and reduced the repetitive action potential firing of PPNs. Analysis of the current–voltage relationship revealed that the EM-2-induced current was reversed at −95 ± 2.5 mV and was suppressed by perfusion of the potassium channel blockers 4-aminopyridine (4-AP) or BaCl2 or by the addition of guanosine 5′-[β-thio]diphosphate trilithium salt (GDP-β-S) to the pipette solution, suggesting the involvement of the G-protein-coupled inwardly rectifying potassium (GIRK) channel. The above EM-2-invoked inhibitory effects were abolished by the MOR selective antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), indicating that the effects of EM-2 on PPNs were mediated by MOR via pre- and/or post-synaptic mechanisms. EM-2 activated pre- and post-synaptic MORs, inhibiting excitatory neurotransmitter release from the presynaptic terminals and decreasing the excitability of PPNs due to hyperpolarization of their membrane potentials, respectively. These inhibitory effects of EM-2 on PPNs at the spinal cord level may explain the mechanism of action of morphine treatment and morphine-induced bladder dysfunction in the clinic.
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Affiliation(s)
- Ying-Biao Chen
- Department of Anatomy, Histology and Embryology, Fujian Medical University Fuzhou, China
| | - Fen-Sheng Huang
- Department of Anatomy, Histology and Embryology and K. K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China ; Division of Medical Biophysics, Institute of Neuroscience and Physiology, Göteborg University Göteborg, Sweden
| | - Ban Fen
- Department of Anatomy, Histology and Embryology and K. K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Jun-Bin Yin
- Department of Anatomy, Histology and Embryology and K. K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Wei Wang
- Department of Anatomy, Histology and Embryology, Fujian Medical University Fuzhou, China
| | - Yun-Qing Li
- Department of Anatomy, Histology and Embryology, Fujian Medical University Fuzhou, China ; Department of Anatomy, Histology and Embryology and K. K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China ; Collaborative Innovation Center for Brain Science, Fudan University Shanghai, China
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Henderson G. The μ-opioid receptor: an electrophysiologist's perspective from the sharp end. Br J Pharmacol 2014; 172:260-7. [PMID: 24640948 DOI: 10.1111/bph.12633] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 12/02/2013] [Accepted: 12/10/2013] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Morphine, the prototypical opioid analgesic drug, produces its behavioural effects primarily through activation of μ-opioid receptors expressed in neurones of the central and peripheral nervous systems. This perspective provides a historical view of how, over the past 40 years, the use of electrophysiological recording techniques has helped to reveal the molecular mechanisms by which acute and chronic activation of μ-opioid receptors by morphine and other opioid drugs modify neuronal function. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.
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Affiliation(s)
- Graeme Henderson
- School of Physiology and Pharmacology, University of Bristol, Bristol, UK
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Zhang C, Tonsfeldt KJ, Qiu J, Bosch MA, Kobayashi K, Steiner RA, Kelly MJ, Rønnekleiv OK. Molecular mechanisms that drive estradiol-dependent burst firing of Kiss1 neurons in the rostral periventricular preoptic area. Am J Physiol Endocrinol Metab 2013; 305:E1384-97. [PMID: 24105416 PMCID: PMC3882370 DOI: 10.1152/ajpendo.00406.2013] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Kisspeptin (Kiss1) neurons in the rostral periventricular area of the third ventricle (RP3V) provide excitatory drive to gonadotropin-releasing hormone (GnRH) neurons to control fertility. Using whole cell patch clamp recording and single-cell (sc)RT-PCR techniques targeting Kiss1-CreGFP or tyrosine hydroxylase (TH)-EGFP neurons, we characterized the biophysical properties of these neurons and identified the critical intrinsic properties required for burst firing in 17β-estradiol (E2)-treated, ovariectomized female mice. One-fourth of the RP3V Kiss1 neurons exhibited spontaneous burst firing. RP3V Kiss1 neurons expressed a hyperpolarization-activated h-current (Ih) and a T-type calcium current (IT), which supported hyperpolarization-induced rebound burst firing. Under voltage clamp conditions, all Kiss1 neurons expressed a kinetically fast Ih that was augmented 3.4-fold by high (LH surge-producing)-E2 treatment. scPCR analysis of Kiss1 neurons revealed abundant expression of the HCN1 channel transcripts. Kiss1 neurons also expressed a Ni(2+)- and TTA-P2-sensitive IT that was augmented sixfold with high-E2 treatment. CaV3.1 mRNA was also highly expressed in these cells. Current clamp analysis revealed that rebound burst firing was induced in RP3V Kiss1 neurons in high-E2-treated animals, and the majority of Kiss1 neurons had a hyperpolarization threshold of -84.7 mV, which corresponded to the V½ for IT de-inactivation. Finally, Kiss1 neurons in the RP3V were hyperpolarized by μ- and κ-opioid and GABAB receptor agonists, suggesting that these pathways also contribute to rebound burst firing. Therefore, Kiss1 neurons in the RP3V express the critical channels and receptors that permit E2-dependent rebound burst firing and provide the biophysical substrate that drives the preovulatory surge of GnRH.
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Affiliation(s)
- Chunguang Zhang
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland Oregon
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Opiate-induced molecular and cellular plasticity of ventral tegmental area and locus coeruleus catecholamine neurons. Cold Spring Harb Perspect Med 2013; 2:a012070. [PMID: 22762025 DOI: 10.1101/cshperspect.a012070] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The study of neuronal adaptations induced by opiate drugs is particularly relevant today given their widespread prescription and nonprescription use. Although much is known about the acute actions of such drugs on the nervous system, a great deal of work remains to fully understand their chronic effects. Here, we focus on longer-lasting adaptations that occur in two catecholaminergic brain regions that mediate distinct behavioral actions of opiates: ventral tegmental area (VTA) dopaminergic neurons, important for drug reward, and locus coeruleus (LC) noradrenergic neurons, important for physical dependence and withdrawal. We focus on changes in cellular, synaptic, and structural plasticity in these brain regions that contribute to opiate dependence and addiction. Understanding the molecular determinants of this opiate-induced plasticity will be critical for the development of better treatments for opiate addiction and perhaps safer opiate drugs for medicinal use.
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Role of GIRK channels on the noradrenergic transmission in vivo: an electrophysiological and neurochemical study on GIRK2 mutant mice. Int J Neuropsychopharmacol 2013; 16:1093-104. [PMID: 23040084 DOI: 10.1017/s1461145712000971] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Dysfunctional noradrenergic transmission is related to several neuropsychiatric conditions, such as depression. Nowadays, the role of G protein-coupled inwardly rectifying potassium (GIRK)2 subunit containing GIRK channels controlling neuronal intrinsic excitability in vitro is well known. The aim of this study was to investigate the impact of GIRK2 subunit mutation on the central noradrenergic transmission in vivo. For that purpose, single-unit extracellular activity of locus coeruleus (LC) noradrenergic neurons and brain monoamine levels using the HPLC technique were measured in wild-type and GIRK2 mutant mice. Girk2 gene mutation induced significant differences among genotypes regarding burst activity of LC neurons. In fact, the proportion of neurons displaying burst firing was increased in GIRK2 heterozygous mice as compared to that recorded from wild-type mice. Furthermore, this augmentation was even greater in the homozygous genotype. However, neither the basal firing rate nor the coefficient of variation of LC neurons was different among genotypes. Noradrenaline and serotonin basal levels were altered in the dorsal raphe nucleus from GIRK2 heterozygous and homozygous mice, respectively. Furthermore, noradrenaline levels were increased in LC projecting areas such as the hippocampus and amygdale from homozygous mice, although not in the prefrontal cortex. Finally, potency of clonidine and morphine inhibiting LC activity was reduced in GIRK2 mutant mice, although the efficacy remained unchanged. Altogether, the present study supports the role of GIRK2 subunit-containing GIRK channels on the maintenance of tonic noradrenergic activity in vivo. Electric and neurochemical consequences derived from an altered GIRK2-dependent signalling could facilitate the understanding of the neurobiological basis of pathologies related to a dysfunctional monoaminergic transmission.
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Glutamate input to noradrenergic neurons plays an essential role in the development of morphine dependence and psychomotor sensitization. Int J Neuropsychopharmacol 2012; 15:1457-71. [PMID: 22040728 DOI: 10.1017/s1461145711001568] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The brain's noradrenergic system is involved in the development of behaviours induced by drugs of abuse, e.g. dependence and withdrawal, and also reward or psychomotor effects. To investigate how noradrenergic system activity is controlled in the context associated with drug-induced behaviours, we generated a Cre/loxP mouse model in which the essential glutamate NMDA receptor subunit NR1 is ablated in cells expressing dopamine β-hydroxylase (Dbh). As a result, the noradrenergic cells in NR1DbhCre mice lack the NMDA receptor-dependent component of excitatory post-synaptic currents. The mutant mice displayed no obvious behavioural alterations, had unchanged noradrenaline content and mild increase in dopamine levels in the nucleus accumbens. Interestingly, NR1DbhCre animals did not develop morphine-induced psychomotor sensitization. However, when the morphine injections were preceded by treatment with RX821002, an antagonist of α2-adrenergic receptors, the development of sensitization was restored. Conversely, pretreatment with clonidine, an agonist of α2-adrenergic receptors, blocked development of sensitization in wild-type mice. We also found that while the development of tolerance to morphine was normal in mutant mice, withdrawal symptoms were attenuated. These data reveal that NMDA receptors on noradrenergic neurons regulate development of opiate dependence and psychomotor sensitization, by controlling drug-induced noradrenaline signalling.
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Honda H, Kawasaki Y, Baba H, Kohno T. The mu opioid receptor modulates neurotransmission in the rat spinal ventral horn. Anesth Analg 2012; 115:703-12. [PMID: 22584545 DOI: 10.1213/ane.0b013e318259393d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Opioids inhibit excitatory neurotransmission and produce antinociception through μ opioid receptors (MORs). Although MORs are expressed in the spinal ventral horn, their functions and effects are largely unknown. Therefore, we examined the neuromodulatory effects of μ opioids in spinal lamina IX neurons at the cellular level. METHODS The effects of the selective μ agonist [D-Ala(2),-N-Me-Phe(4), Gly(5)-ol]enkephalin (DAMGO) on synaptic transmission were examined in spinal lamina IX neurons of neonatal rats using the whole-cell patch-clamp technique. RESULTS DAMGO produced outward currents in 56% of the lamina IX neurons recorded, with a 50% effective concentration of 0.1 μM. Analysis of the current-voltage relationship revealed a reversal potential of approximately -86 mV. These currents were not blocked by tetrodotoxin but were inhibited by Ba(2+) or a selective μ antagonist. Moreover, the currents were suppressed by the addition of Cs(+) and tetraethylammonium or guanosine 5'-[β-thio]diphosphate trilithium salt to the pipette solution. In addition, DAMGO decreased the frequency of spontaneous excitatory and inhibitory postsynaptic currents, and these effects were unaltered by treatment with tetrodotoxin. CONCLUSION Our results suggest that DAMGO hyperpolarizes spinal lamina IX neurons by G protein-mediated activation of K(+) channels after activation of MORs. Furthermore, activation of MORs on presynaptic terminals reduces both excitatory and inhibitory transmitter release. Although traditionally opioids are not thought to affect motor function, the present study documents neuromodulatory effects of μ opioids in spinal lamina IX neurons, suggesting that MORs can influence motor activity.
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Affiliation(s)
- Hiroyuki Honda
- Division of Anesthesiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Banghart MR, Sabatini BL. Photoactivatable neuropeptides for spatiotemporally precise delivery of opioids in neural tissue. Neuron 2012; 73:249-59. [PMID: 22284180 PMCID: PMC3282187 DOI: 10.1016/j.neuron.2011.11.016] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2011] [Indexed: 12/19/2022]
Abstract
Neuropeptides activate G protein-coupled receptors to acutely modulate cellular excitability and synaptic transmission. However, due to the lack of reagents for precise delivery of peptides within dense brain tissue, the spatiotemporal scale over which neuropeptides act is unknown. To achieve rapid and spatially delimited delivery of neuropeptides in mammalian brain tissue, we developed photoactivatable analogs of two opioids: [Leu⁵]-enkephalin (LE) and the 8 amino acid form of Dynorphin A (Dyn-8). These peptides are functionally inactive prior to photolysis, and exposure to ultraviolet (UV) light causes clean release of LE and Dyn-8. Recordings from acute slices of rat locus coeruleus (LC) demonstrated that photorelease of LE activates mu opioid receptor-coupled K+ channels with kinetics that approach the limits imposed by G protein-mediated signaling. Temporally precise and spatially delimited photorelease revealed the kinetics and ionic nature of the mu opioid response and the mechanisms that determine the spatial profile of enkephalinergic volume transmission in LC.
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Affiliation(s)
- Matthew R. Banghart
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Bernardo L. Sabatini
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
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Belardetti F, Schacher S, Kandel ER, Siegelbaum SA. The growth cones of Aplysia sensory neurons: Modulation by serotonin of action potential duration and single potassium channel currents. Proc Natl Acad Sci U S A 2010; 83:7094-8. [PMID: 16593764 PMCID: PMC386659 DOI: 10.1073/pnas.83.18.7094] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Serotonin (5-HT) closes a specific K channel ("S") in the cell body of Aplysia sensory neurons, resulting in a slow excitatory postsynaptic potential and spike broadening. To determine whether the S channel is present and can be modulated in processes of the neuron other than the cell body, we studied the effects of 5-HT on growth cones of sensory neurons in culture by using the patch-clamp technique. Simultaneous application of 5-HT to the cell body and to the growth cones of sensory neurons produced, in both, a slow depolarization of approximately 5 mV. Also, 5-HT produced a lengthening of the duration of action potential in the growth cone and cell body by 20-30%. Similar effects were observed in isolated growth cones that had been severed from the rest of the neuron, implying that the growth cones contain all the molecular components (i.e., receptors, channels, cAMP cascade) necessary for 5-HT action. Cell-attached patch-clamp recordings demonstrated the presence of S channels in sensory neuron growth cones. Application of serotonin to the bath produced long-lasting all-or-none closures of these channels in a manner identical to the previously characterized action of 5-HT in the cell body. Thus, channel modulation is not restricted to the cell body and probably occurs throughout the sensory neuron. This strengthens the view that S-channel modulation may also occur at the sensory neuron presynaptic terminal, where it could play a role in the presynaptic facilitation produced by 5-HT.
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Affiliation(s)
- F Belardetti
- Howard Hughes Medical Institute, Columbia University, 722 West 168 Street, New York, NY 10032
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Lal A, Oku Y, Hülsmann S, Okada Y, Miwakeichi F, Kawai S, Tamura Y, Ishiguro M. Dual oscillator model of the respiratory neuronal network generating quantal slowing of respiratory rhythm. J Comput Neurosci 2010; 30:225-40. [PMID: 20544264 PMCID: PMC3058346 DOI: 10.1007/s10827-010-0249-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Revised: 03/10/2010] [Accepted: 05/24/2010] [Indexed: 11/28/2022]
Abstract
We developed a dual oscillator model to facilitate the understanding of dynamic interactions between the parafacial respiratory group (pFRG) and the preBötzinger complex (preBötC) neurons in the respiratory rhythm generation. Both neuronal groups were modeled as groups of 81 interconnected pacemaker neurons; the bursting cell model described by Butera and others [model 1 in Butera et al. (J Neurophysiol 81:382–397, 1999a)] were used to model the pacemaker neurons. We assumed (1) both pFRG and preBötC networks are rhythm generators, (2) preBötC receives excitatory inputs from pFRG, and pFRG receives inhibitory inputs from preBötC, and (3) persistent Na+ current conductance and synaptic current conductances are randomly distributed within each population. Our model could reproduce 1:1 coupling of bursting rhythms between pFRG and preBötC with the characteristic biphasic firing pattern of pFRG neurons, i.e., firings during pre-inspiratory and post-inspiratory phases. Compatible with experimental results, the model predicted the changes in firing pattern of pFRG neurons from biphasic expiratory to monophasic inspiratory, synchronous with preBötC neurons. Quantal slowing, a phenomena of prolonged respiratory period that jumps non-deterministically to integer multiples of the control period, was observed when the excitability of preBötC network decreased while strengths of synaptic connections between the two groups remained unchanged, suggesting that, in contrast to the earlier suggestions (Mellen et al., Neuron 37:821–826, 2003; Wittmeier et al., Proc Natl Acad Sci USA 105(46):18000–18005, 2008), quantal slowing could occur without suppressed or stochastic excitatory synaptic transmission. With a reduced excitability of preBötC network, the breakdown of synchronous bursting of preBötC neurons was predicted by simulation. We suggest that quantal slowing could result from a breakdown of synchronized bursting within the preBötC.
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Affiliation(s)
- Amit Lal
- Department of Physiology, Hyogo College of Medicine, Nishinomiya, Hyogo, 663-8501, Japan
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Van Bockstaele EJ, Reyes BAS, Valentino RJ. The locus coeruleus: A key nucleus where stress and opioids intersect to mediate vulnerability to opiate abuse. Brain Res 2010; 1314:162-74. [PMID: 19765557 PMCID: PMC3274960 DOI: 10.1016/j.brainres.2009.09.036] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 08/19/2009] [Accepted: 09/10/2009] [Indexed: 12/29/2022]
Abstract
The interaction between the stress axis and endogenous opioid systems has gained substantial clinical attention as it is increasingly recognized that stress predisposes to opiate abuse. For example, stress has been implicated as a risk factor in vulnerability to the initiation and maintenance of opiate abuse and is thought to play an important role in relapse in subjects with a history of abuse. Numerous reports indicating that stress alters individual sensitivity to opiates suggest that prior stress can influence the pharmacodynamics of opiates that are used in clinical settings. Conversely, the effects of opiates on different components of the stress axis can impact on individual responsivity to stressors and potentially predispose individuals to stress-related psychiatric disorders. One site at which opiates and stress substrates may interact to have global effects on behavior is within the locus coeruleus (LC), the major brain norepinephrine (NE)-containing nucleus. This review summarizes our current knowledge regarding the anatomical and neurochemical afferent regulation of the LC. It then presents physiological studies demonstrating opposing interactions between opioids and stress-related neuropeptides in the LC and summarizes results showing that chronic morphine exposure sensitizes the LC-NE system to corticotropin releasing factor and stress. Finally, new evidence for novel presynaptic actions of kappa-opioids on LC afferents is provided that adds another dimension to our model of how this central NE system is co-regulated by opioids and stress-related peptides.
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Affiliation(s)
- E J Van Bockstaele
- Department of Neurosurgery, Thomas Jefferson University, Farber Institute for Neurosciences, 900 Walnut Street, Suite 400, Philadelphia, PA 19107, USA.
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Hibino H, Inanobe A, Furutani K, Murakami S, Findlay I, Kurachi Y. Inwardly rectifying potassium channels: their structure, function, and physiological roles. Physiol Rev 2010; 90:291-366. [PMID: 20086079 DOI: 10.1152/physrev.00021.2009] [Citation(s) in RCA: 1074] [Impact Index Per Article: 76.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Inwardly rectifying K(+) (Kir) channels allow K(+) to move more easily into rather than out of the cell. They have diverse physiological functions depending on their type and their location. There are seven Kir channel subfamilies that can be classified into four functional groups: classical Kir channels (Kir2.x) are constitutively active, G protein-gated Kir channels (Kir3.x) are regulated by G protein-coupled receptors, ATP-sensitive K(+) channels (Kir6.x) are tightly linked to cellular metabolism, and K(+) transport channels (Kir1.x, Kir4.x, Kir5.x, and Kir7.x). Inward rectification results from pore block by intracellular substances such as Mg(2+) and polyamines. Kir channel activity can be modulated by ions, phospholipids, and binding proteins. The basic building block of a Kir channel is made up of two transmembrane helices with cytoplasmic NH(2) and COOH termini and an extracellular loop which folds back to form the pore-lining ion selectivity filter. In vivo, functional Kir channels are composed of four such subunits which are either homo- or heterotetramers. Gene targeting and genetic analysis have linked Kir channel dysfunction to diverse pathologies. The crystal structure of different Kir channels is opening the way to understanding the structure-function relationships of this simple but diverse ion channel family.
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Affiliation(s)
- Hiroshi Hibino
- Department of Pharmacology, Graduate School of Medicine and The Center for Advanced Medical Engineering and Informatics, Osaka University, Osaka 565-0871, Japan
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Torrecilla M, Quillinan N, Williams JT, Wickman K. Pre- and postsynaptic regulation of locus coeruleus neurons after chronic morphine treatment: a study of GIRK-knockout mice. Eur J Neurosci 2008; 28:618-24. [PMID: 18702733 DOI: 10.1111/j.1460-9568.2008.06348.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
While the acute inhibitory effect of opioids on locus coeruleus (LC) neurons is mediated primarily by the activation of G protein-gated inwardly-rectifying K(+) (GIRK) channels, the 3'-5'-cyclic adenosine monophosphate (cAMP) system has been implicated in the effects of chronic morphine exposure. Presently, the impact of chronic morphine treatment on GIRK-dependent and GIRK-independent mechanisms underlying the opioid-induced inhibition of LC neurons is unclear. Here, opioid-induced postsynaptic inhibition was studied in LC neurons from wild-type and GIRK2/GIRK3(-/-) mice at baseline and following chronic morphine treatment. The postsynaptic inhibition of LC neurons caused by the opioid agonist [Met](5) enkephalin (ME) was unaffected by chronic morphine treatment in mice of either genotype. Furthermore, chronic morphine treatment had no effect on the forskolin augmentation of the ME-induced current in wild-type LC neurons and only a minor effect on the ME-induced current in LC neurons from GIRK2/GIRK3(-/-) mice. Chronic morphine treatment did, however, lead to an increased frequency of spontaneous excitatory postsynaptic currents (EPSCs) in the LC. Interestingly, while forskolin augmented the EPSC frequency similarly in untreated and morphine-treated wild-type mice, as well as untreated GIRK2/GIRK3(-/-) mice, it failed to increase the frequency of EPSCs in morphine-treated GIRK2/GIRK3(-/-) mice. Altogether, the findings suggest that chronic morphine treatment exerts little impact on ion channels and signaling pathways that mediate the postsynaptic inhibitory effects of opioids but does enhance excitatory neurotransmission in the mouse LC.
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Affiliation(s)
- Maria Torrecilla
- Vollum Institute, Oregon Health Sciences University, Portland, OR, USA
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Reyes BAS, Drolet G, Van Bockstaele EJ. Dynorphin and stress-related peptides in rat locus coeruleus: contribution of amygdalar efferents. J Comp Neurol 2008; 508:663-75. [PMID: 18381633 PMCID: PMC3277290 DOI: 10.1002/cne.21683] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The interaction between the stress axis and endogenous opioid systems has gained substantial attention, because it is increasingly recognized that stress alters individual sensitivity to opiates. One site at which opiates and stress substrates may interact to have global effects on behavior is within the locus coeruleus (LC). We have previously described interactions of several opioid peptides [e.g., proopiomelanocortin, enkephalin (ENK)] with the stress-related peptide corticotropin-releasing factor (CRF) in the LC. To examine further the interactions among dynorphin (DYN), ENK, and CRF in the LC, sections were processed for detection of DYN and CRF or DYN and ENK in rat brain. DYN- and CRF-containing axon terminals overlapped noradrenergic dendrites in this region. Dual immunoelectron microscopy showed coexistence of DYN and CRF; 35% of axon terminals containing DYN were also immunoreactive for CRF. In contrast, few axon terminals contained both DYN and ENK. A potential DYN/CRF afferent is the central nucleus of the amygdala (CeA). Dual in situ hybridization showed that, in CeA neurons, 31% of DYN mRNA-positive cells colocalized with CRF mRNA, whereas 53% of CRF mRNA-containing cells colocalized with DYN mRNA. Finally, to determine whether limbic DYN afferents target the LC, the CeA was electrolytically lesioned. Light-level densitometry of DYN labeling in the LC showed a significant decrease in immunoreactivity on the side of the lesion. Taken together, these data indicate that DYN- and CRF-labeled axon terminals, most likely arising from amygdalar sources, are positioned dually to affect LC function, whereas DYN and ENK function in parallel.
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Affiliation(s)
- B A S Reyes
- Department of Neurosurgery, Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
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Rutten M, Govindaswami M, Oeltgen P, Sonneborn JS. Post-treatment with the novel deltorphin E, a delta2-opioid receptor agonist, increases recovery and survival after severe hemorrhagic shock in behaving rats. Shock 2008; 29:42-8. [PMID: 17621254 DOI: 10.1097/shk.0b013e31805cdb70] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Deltorphin E was investigated as a pharmaceutical intervention in the ischemic hemorrhagic model. To monitor the hemodynamic biomarkers mean arterial pressure (MAP) and heart rate (HR) and to facilitate i.v. injections, rats were surgically fitted with femoral artery and vein catheters under anesthesia. After removal of 48% of total blood volume (range, 12-15 mL), posthemorrhage i.v. injections of 5.5-mg/kg deltorphin E were found to significantly (P < 0.05) increase maximum MAP, pulse pressure, and survival after hemorrhage, whereas lactic acid concentration was decreased when compared with saline injections. The results for the 5.5-mg/kg deltorphin E-treated animals versus saline controls showed the following values (expressed as mean +/- SEM): maximum MAP, 58 +/- 7 vs. 35 +/- 9 mmHg, respectively; lactic acid, 6.5 +/- 1.25 vs. 8.9 +/- 0.12 mmol/L, respectively; pulse pressure, 47.9 +/- 0.55 vs. 38.3 +/- 0.44 mmHg, respectively; and at least a fourfold increase in survival, 331 +/- 18 vs. 50 +/- 8 min, respectively. Heart rate in deltorphin E-treated groups was not significantly different from that in saline-treated groups (maximum HR, 396 +/- 40 vs. 425 +/- 94 bpm, respectively). Using logistic analysis, deltorphin E did not significantly alter the baroreflex sensitivity. However, a significant deltorphin E dose-dependent correlation was found between survival time and lactic acid production. Increased pulse pressure was also correlated with survival. Glibenclamide, a potassium-sensitive adenosine triphosphate-sensitive channel blocker, did not interfere with the positive effects of deltorphin E. Only the antagonists tested, known to affect delta(2)-opioid receptors, interfered with the deltorphin E survival benefit after hemorrhage. As a conclusion, deltorphin E is an effective pharmaceutical intervention in severe hemorrhagic shock and, perhaps, in other ischemic shock scenarios when administered after the onset of stress. Therefore, deltorphin E may have clinical potential.
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Affiliation(s)
- Mikal Rutten
- Zoology and Physiology Department Graduate Program, University of Wyoming, Laramie, Wyoming 8207, USA
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Valentino RJ, Van Bockstaele E. Convergent regulation of locus coeruleus activity as an adaptive response to stress. Eur J Pharmacol 2008; 583:194-203. [PMID: 18255055 DOI: 10.1016/j.ejphar.2007.11.062] [Citation(s) in RCA: 383] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 10/01/2007] [Accepted: 11/14/2007] [Indexed: 11/26/2022]
Abstract
Although hypothalamic-pituitary-adrenal axis activation is generally considered to be the hallmark of the stress response, many of the same stimuli that initiate this response also activate the locus coeruleus-norepinephrine system. Given its functional attributes, the parallel engagement of the locus coeruleus-norepinephrine system with the hypothalamic-pituitary-adrenal axis serves to coordinate endocrine and cognitive limbs of the stress response. The elucidation of stress-related afferents to the locus coeruleus and the electrophysiological characterization of these inputs are revealing how the activity of this system is fine-tuned by stressors to facilitate adaptive cognitive responses. Emerging from these studies, is a picture of complex interactions between the stress-related neuropeptide, corticotropin-releasing factor (CRF), endogenous opioids and the excitatory amino acid neurotransmitter, glutamate. The net effect of these interactions is to adjust the activity and reactivity of the locus coeruleus-norepinephrine system such that state of arousal and processing of sensory stimuli are modified to facilitate adaptive behavioral responses to stressors. This review begins with an introduction to the basic anatomical and physiological characteristics of locus coeruleus neurons. The concept that locus coeruleus neurons operate through two activity modes, i.e., tonic vs. phasic, that determine distinct behavioral strategies is emphasized in light of its relevance to stress. Anatomical and physiological evidence are then presented suggesting that interactions between stress-related neurotransmitters that converge on locus coeruleus neurons regulate shifts between these modes of discharge in response to the challenge of a stressor. This review focuses specifically on the locus coeruleus because it is the major source of norepinephrine to the forebrain and has been implicated in behavioral and cognitive aspects of stress responses.
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Affiliation(s)
- Rita J Valentino
- The Children's Hospital of Philadelphia, 402C Abramson Building, Osler Cr., Philadelphia, PA 19104, United States.
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Jose X, Pineda JC, Rodriguez C, Mendoza E, Galarraga E, Bargas J, Barral J. Delta opioids reduce the neurotransmitter release probability by enhancing transient (KV4) K+-currents in corticostriatal synapses as evaluated by the paired pulse protocol. Neurosci Lett 2007; 414:150-4. [PMID: 17197081 DOI: 10.1016/j.neulet.2006.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 11/28/2006] [Accepted: 12/08/2006] [Indexed: 11/17/2022]
Abstract
Field recordings were used to determine the influence of delta-opioid receptor activation on corticostriatal synaptic transmission. Application of the selective delta-opioid receptor agonist, [Tyr-D-Pen-Gly-Phe-D-Pen]-enkephalin (DPDPE, 1 microM), decreased the amplitude of the field-excitatory synaptic potential and at the same time increased the paired pulse ratio (PPR) suggesting a presynaptic site of action. This response reversed rapidly when DPDPE was washed and blocked by 1 nM of the selective delta-receptor antagonist naltrindole. Neither omega-conotoxin GVIA (1 microM) nor omega-agatoxin TK (400 nM), blockers of N- and P/Q-type Ca2+-channels, respectively, nor TEA (1 mM), blocker of some classes of K+-channels, occluded the effects of DPDPE. Instead, 1 mM 4-AP or 400 microM Ba2+ occluded completely the effects of DPDPE. Therefore, the results suggest that the modulation by delta opioids at corticostriatal terminals is mediated by transient (KV4) K+-conductances.
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MESH Headings
- Analgesics, Opioid/pharmacology
- Animals
- Calcium Channel Blockers/pharmacology
- Cerebral Cortex/drug effects
- Cerebral Cortex/metabolism
- Corpus Striatum/drug effects
- Corpus Striatum/metabolism
- Electric Stimulation
- Enkephalin, D-Penicillamine (2,5)-/pharmacology
- Excitatory Postsynaptic Potentials/drug effects
- Excitatory Postsynaptic Potentials/physiology
- Male
- Narcotic Antagonists/pharmacology
- Neural Pathways/drug effects
- Neural Pathways/metabolism
- Neurotransmitter Agents/metabolism
- Opioid Peptides/metabolism
- Organ Culture Techniques
- Potassium Channel Blockers/pharmacology
- Presynaptic Terminals/drug effects
- Presynaptic Terminals/metabolism
- Rats
- Rats, Wistar
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Shal Potassium Channels/agonists
- Shal Potassium Channels/antagonists & inhibitors
- Shal Potassium Channels/metabolism
- Synaptic Transmission/drug effects
- Synaptic Transmission/physiology
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Affiliation(s)
- Xochitl Jose
- Neurociencias, FES Iztacala, Universidad Nacional Autónoma de México, Mexico
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Pecoraro N, Dallman MF, Warne JP, Ginsberg AB, Laugero KD, la Fleur SE, Houshyar H, Gomez F, Bhargava A, Akana SF. From Malthus to motive: how the HPA axis engineers the phenotype, yoking needs to wants. Prog Neurobiol 2006; 79:247-340. [PMID: 16982128 DOI: 10.1016/j.pneurobio.2006.07.004] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Revised: 07/17/2006] [Accepted: 07/24/2006] [Indexed: 01/28/2023]
Abstract
The hypothalamo-pituitary-adrenal (HPA) axis is the critical mediator of the vertebrate stress response system, responding to environmental stressors by maintaining internal homeostasis and coupling the needs of the body to the wants of the mind. The HPA axis has numerous complex drivers and highly flexible operating characterisitics. Major drivers include two circadian drivers, two extra-hypothalamic networks controlling top-down (psychogenic) and bottom-up (systemic) threats, and two intra-hypothalamic networks coordinating behavioral, autonomic, and neuroendocrine outflows. These various networks jointly and flexibly control HPA axis output of periodic (oscillatory) functions and a range of adventitious systemic or psychological threats, including predictable daily cycles of energy flow, actual metabolic deficits over many time scales, predicted metabolic deficits, and the state-dependent management of post-prandial responses to feeding. Evidence is provided that reparation of metabolic derangement by either food or glucocorticoids results in a metabolic signal that inhibits HPA activity. In short, the HPA axis is intimately involved in managing and remodeling peripheral energy fluxes, which appear to provide an unidentified metabolic inhibitory feedback signal to the HPA axis via glucocorticoids. In a complementary and perhaps a less appreciated role, adrenocortical hormones also act on brain to provide not only feedback, but feedforward control over the HPA axis itself and its various drivers, as well as coordinating behavioral and autonomic outflows, and mounting central incentive and memorial networks that are adaptive in both appetitive and aversive motivational modes. By centrally remodeling the phenotype, the HPA axis provides ballistic and predictive control over motor outflows relevant to the type of stressor. Evidence is examined concerning the global hypothesis that the HPA axis comprehensively induces integrative phenotypic plasticity, thus remodeling the body and its governor, the brain, to yoke the needs of the body to the wants of the mind. Adverse side effects of this yoking under conditions of glucocorticoid excess are discussed.
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Affiliation(s)
- Norman Pecoraro
- Department of Physiology, University of California, San Francisco, CA 94143-0444, United States.
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Illes P. Modulation of transmitter and hormone release by multiple neuronal opioid receptors. Rev Physiol Biochem Pharmacol 2005; 112:139-233. [PMID: 2573137 DOI: 10.1007/bfb0027497] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Reyes BAS, Valentino RJ, Xu G, Van Bockstaele EJ. Hypothalamic projections to locus coeruleus neurons in rat brain. Eur J Neurosci 2005; 22:93-106. [PMID: 16029199 DOI: 10.1111/j.1460-9568.2005.04197.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Locus coeruleus (LC) neurons respond to autonomic and visceral stimuli and discharge in parallel with peripheral sympathetic nerves. The present study characterized the synaptic organization of hypothalamic afferents with catecholaminergic neurons in the LC using electron microscopy. Peroxidase labeling of axon terminals that were anterogradely labeled from the paraventricular nucleus (PVN) was combined with gold-silver labeling of tyrosine hydroxylase in the LC. Approximately 19% of the anterogradely labeled axon terminals formed synaptic specializations with tyrosine hydroxylase-immunoreactive dendrites in the LC. Retrograde transport from the LC combined with immunocytochemical detection of enkephalin and corticotropin-releasing factor (CRF) suggested that most of the LC-projecting PVN neurons (30%) were CRF immunoreactive and few (2%) were enkephalin immunoreactive. Finally, dual retrograde tracing from the LC and median eminence revealed that PVN neurons that project to the LC are a population distinct from that projecting to the median eminence. The present data suggest that a population of hypothalamic neurons is poised to directly modulate the activity of LC neurons and may integrate autonomic responses in brain by influencing LC neurons. Moreover, PVN neurons that use CRF as a neurohormone are distinct from those that use CRF as a neuromodulator to impact on the LC.
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Affiliation(s)
- Beverly A S Reyes
- Department of Neurosurgery, Farber Institute for Neurosciences, Thomas Jefferson University, 900 Walnut Street, Suite 400, Philadelphia, PA 19107, USA.
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Guang W, Wang H, Su T, Weinstein IB, Wang JB. Role of mPKCI, a Novel μ-Opioid Receptor Interactive Protein, in Receptor Desensitization, Phosphorylation, and Morphine-Induced Analgesia. Mol Pharmacol 2004. [DOI: 10.1124/mol.66.5.1285] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Abstract
Functional interactions between G protein-coupled receptors (GPCRs) are widely reported whereas the mechanisms underlying these interactions remain unclear. A rapidly growing literature suggests that many GPCRs form heteromeric complexes and that these complexes may possess pharmacological and functional properties that differ from their respective parent receptors. In order to investigate the functional relationship between co-localized GPCRs in intact, native CNS neurons, we used intracellular recording techniques in locus coeruleus (LC) slices. The LC consists of a homogenous population of cells, all of which co-express micro-opioid and alpha(2A)-adrenergic receptors (microOR and alpha(2A)ARs, respectively). Co-administration of microOR and alpha(2A)AR agonists in vivo results in synergistic interactions in analgesic assays and heteromeric microOR-alpha(2A)AR complexes have been detected in HEK-293 co-expressing the two receptors. The LC is therefore an excellent model system to explore these interactions. Dose-response and isobolographic analysis of agonist-induced hyperpolarization in individual LC neurons revealed that the interaction between these receptors was not synergistic but additive. This result suggests that co-localized microOR and alpha(2)ARs are either not physically associated in these neurons or that heteromer formation may not fully explain the microOR-alpha(2A)AR synergistic interactions reported following agonist administration in vivo.
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MESH Headings
- Action Potentials/drug effects
- Action Potentials/physiology
- Adrenergic alpha-Agonists/pharmacology
- Animals
- Animals, Newborn
- Dose-Response Relationship, Drug
- Drug Synergism
- In Vitro Techniques
- Locus Coeruleus/drug effects
- Locus Coeruleus/metabolism
- Narcotics/pharmacology
- Neural Inhibition/drug effects
- Neural Inhibition/physiology
- Neurons/drug effects
- Neurons/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/metabolism
- Receptors, G-Protein-Coupled/drug effects
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/metabolism
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Affiliation(s)
- Laura S Stone
- Department of Neuroscience, University of Minnesota, 6-145 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, USA.
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Faber ESL, Sah P. Opioids inhibit lateral amygdala pyramidal neurons by enhancing a dendritic potassium current. J Neurosci 2004; 24:3031-9. [PMID: 15044542 PMCID: PMC6729839 DOI: 10.1523/jneurosci.4496-03.2004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Pyramidal neurons in the lateral amygdala discharge trains of action potentials that show marked spike frequency adaptation, which is primarily mediated by activation of a slow calcium-activated potassium current. We show here that these neurons also express an alpha-dendrotoxin- and tityustoxin-Kalpha-sensitive voltage-dependent potassium current that plays a key role in the control of spike discharge frequency. This current is selectively targeted to the primary apical dendrite of these neurons. Activation of micro-opioid receptors by application of morphine or d-Ala(2)-N-Me-Phe(4)-Glycol(5)-enkephalin (DAMGO) potentiates spike frequency adaptation by enhancing the alpha-dendrotoxin-sensitive potassium current. The effects of micro-opioid agonists on spike frequency adaptation were blocked by inhibiting G-proteins with N-ethylmaleimide (NEM) and by blocking phospholipase A(2). Application of arachidonic acid mimicked the actions of DAMGO or morphine. These results show that micro-opioid receptor activation enhances spike frequency adaptation in lateral amygdala neurons by modulating a voltage-dependent potassium channel containing Kv1.2 subunits, through activation of the phospholipase A(2)-arachidonic acid-lipoxygenases cascade.
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Affiliation(s)
- E S Louise Faber
- Division of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra ACT 2601, Australia
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Popper P, Cristobal R, Wackym PA. Expression and distribution of μ opioid receptors in the inner ear of the rat. Neuroscience 2004; 129:225-33. [PMID: 15489044 DOI: 10.1016/j.neuroscience.2004.08.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2004] [Indexed: 10/26/2022]
Abstract
Opioid peptides have demonstrated modulatory effects on the vestibular afferent discharge and are putative vestibular efferent neuromodulators. The distribution of their receptors in the mammalian vestibular epithelia is not known. We used reverse transcriptase-polymerase chain reaction (RT-PCR), in situ hybridization, Western blots and immunohistochemistry to study the expression of mu opioid receptor (MOR) in the Scarpa's ganglia and cristae ampullares of rats. MOR transcript was only detected in the somata of the vestibular afferent neurons. MOR-like immunoreactivity was observed in the somata of vestibular afferents and in nerve terminals in the cristae ampullares epithelia both in the center and peripheral regions. Double labeling of cristae sections with the MOR1 antibody in combination with antibodies against calretinin (a marker for vestibular afferents terminating in calices) and peripherin (a marker for afferents terminating in boutons), respectively showed that MOR1 immunoreactivity was in calyx, dimorphic and bouton vestibular afferents. MOR immunoreactivity was not detected in vestibular efferent fibers identified with choline acetyltransferase immunohistochemistry. These results indicate that MOR may mediate effects of vestibular efferents on afferents.
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Affiliation(s)
- P Popper
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, WI 53226, USA.
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50
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Abstract
Opioids have been used and abused by humans for centuries. The mu opioid receptor represents the high affinity binding site for opioid narcotics with high abuse liability such as morphine, codeine and fentanyl. Heroin (diacetylmorphine), a semi-synthetic derivative of morphine, crosses the blood-brain barrier more readily than morphine due to its increased hydrophobicity. Once in the brain heroin is hydrolyzed to morphine, which acts at the mu opioid receptor and results in euphoria, thus conferring the reinforcing properties of heroin. Using molecular biology techniques, the mu opioid receptors from several species have been cloned. This article reviews recent progress in this area, with respect to the two major cellular functions of the mu opioid receptor: reduction of intracellular cAMP concentration by inhibiting adenylyl cyclase activity, and inhibition of neuronal firing by modulating membrane ion channels.
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Affiliation(s)
- L Yu
- Department of Medical and Molecualr Genetics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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