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Amygdala Intercalated Cells: Gate Keepers and Conveyors of Internal State to the Circuits of Emotion. J Neurosci 2022; 42:9098-9109. [PMID: 36639901 PMCID: PMC9761677 DOI: 10.1523/jneurosci.1176-22.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/19/2022] [Accepted: 10/16/2022] [Indexed: 01/09/2023] Open
Abstract
Generating adaptive behavioral responses to emotionally salient stimuli requires evaluation of complex associations between multiple sensations, the surrounding context, and current internal state. Neural circuits within the amygdala parse this emotional information, undergo synaptic plasticity to reflect learned associations, and evoke appropriate responses through their projections to the brain regions orchestrating these behaviors. Information flow within the amygdala is regulated by the intercalated cells (ITCs), which are densely packed clusters of GABAergic neurons that encircle the basolateral amygdala (BLA) and provide contextually relevant feedforward inhibition of amygdala nuclei, including the central and BLA. Emerging studies have begun to delineate the unique contribution of each ITC cluster and establish ITCs as key loci of plasticity in emotional learning. In this review, we summarize the known connectivity and function of individual ITC clusters and explore how different neuromodulators conveying internal state act via ITC gates to shape emotionally motivated behavior. We propose that the behavioral state-dependent function of ITCs, their unique genetic profile, and rich expression of neuromodulator receptors make them potential therapeutic targets for disorders, such as anxiety, schizophrenia spectrum, and addiction.
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2
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Limoges A, Yarur HE, Tejeda HA. Dynorphin/kappa opioid receptor system regulation on amygdaloid circuitry: Implications for neuropsychiatric disorders. Front Syst Neurosci 2022; 16:963691. [PMID: 36276608 PMCID: PMC9579273 DOI: 10.3389/fnsys.2022.963691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/18/2022] [Indexed: 11/13/2022] Open
Abstract
Amygdaloid circuits are involved in a variety of emotional and motivation-related behaviors and are impacted by stress. The amygdala expresses several neuromodulatory systems, including opioid peptides and their receptors. The Dynorphin (Dyn)/kappa opioid receptor (KOR) system has been implicated in the processing of emotional and stress-related information and is expressed in brain areas involved in stress and motivation. Dysregulation of the Dyn/KOR system has also been implicated in various neuropsychiatric disorders. However, there is limited information about the role of the Dyn/KOR system in regulating amygdala circuitry. Here, we review the literature on the (1) basic anatomy of the amygdala, (2) functional regulation of synaptic transmission by the Dyn/KOR system, (3) anatomical architecture and function of the Dyn/KOR system in the amygdala, (4) regulation of amygdala-dependent behaviors by the Dyn/KOR system, and (5) future directions for the field. Future work investigating how the Dyn/KOR system shapes a wide range of amygdala-related behaviors will be required to increase our understanding of underlying circuitry modulation by the Dyn/KOR system. We anticipate that continued focus on the amygdala Dyn/KOR system will also elucidate novel ways to target the Dyn/KOR system to treat neuropsychiatric disorders.
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Affiliation(s)
- Aaron Limoges
- Unit on Neuromodulation and Synaptic Integration, Bethesda, MD, United States
- NIH-Columbia University Individual Graduate Partnership Program, National Institutes of Health, Bethesda, MD, United States
- Department of Biological Sciences, Columbia University, New York, NY, United States
| | - Hector E. Yarur
- Unit on Neuromodulation and Synaptic Integration, Bethesda, MD, United States
| | - Hugo A. Tejeda
- Unit on Neuromodulation and Synaptic Integration, Bethesda, MD, United States
- *Correspondence: Hugo A. Tejeda,
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3
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Reeves KC, Shah N, Muñoz B, Atwood BK. Opioid Receptor-Mediated Regulation of Neurotransmission in the Brain. Front Mol Neurosci 2022; 15:919773. [PMID: 35782382 PMCID: PMC9242007 DOI: 10.3389/fnmol.2022.919773] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/26/2022] [Indexed: 12/15/2022] Open
Abstract
Opioids mediate their effects via opioid receptors: mu, delta, and kappa. At the neuronal level, opioid receptors are generally inhibitory, presynaptically reducing neurotransmitter release and postsynaptically hyperpolarizing neurons. However, opioid receptor-mediated regulation of neuronal function and synaptic transmission is not uniform in expression pattern and mechanism across the brain. The localization of receptors within specific cell types and neurocircuits determine the effects that endogenous and exogenous opioids have on brain function. In this review we will explore the similarities and differences in opioid receptor-mediated regulation of neurotransmission across different brain regions. We discuss how future studies can consider potential cell-type, regional, and neural pathway-specific effects of opioid receptors in order to better understand how opioid receptors modulate brain function.
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Affiliation(s)
- Kaitlin C. Reeves
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Neuroscience, Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, United States
| | - Nikhil Shah
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Medical Scientist Training Program, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Braulio Muñoz
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Brady K. Atwood
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
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4
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Hein M, Ji G, Tidwell D, D'Souza P, Kiritoshi T, Yakhnitsa V, Navratilova E, Porreca F, Neugebauer V. Kappa opioid receptor activation in the amygdala disinhibits CRF neurons to generate pain-like behaviors. Neuropharmacology 2021; 185:108456. [PMID: 33444637 PMCID: PMC7887082 DOI: 10.1016/j.neuropharm.2021.108456] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/01/2021] [Accepted: 01/05/2021] [Indexed: 12/15/2022]
Abstract
Recent evidence suggests that kappa opioid receptors (KOR) in limbic brain regions such as the amygdala contribute to pain conditions, but underlying mechanisms remain to be determined. The amygdala is an important player in averse-affective aspects of pain and pain modulation. The central nucleus (CeA) serves output functions through projection neurons that include corticotropin releasing factor (CRF) expressing neurons. The CeA is also rich in KOR. Here we tested the novel hypothesis that KOR activation in the CeA generates pain-like behaviors through a mechanism that involves inhibition of synaptic inhibition (disinhibition) of CRF neurons. Intra-CeA administration of a KOR agonist (U-69,593) increased vocalizations of naïve rats to noxious stimuli, and induced anxiety-like behaviors in the open field test (OFT) and avoidance in the conditioned place preference test, without affecting mechanosensory thresholds. Optogenetic silencing of CeA-CRF neurons blocked the facilitatory effects of systemically applied U-69,593 in naïve rats. Patch-clamp recordings of CRF neurons in rat brain slices found that U-69,593 decreased feedforward inhibitory transmission evoked by optogenetic stimulation of parabrachial afferents, but had no effect on monosynaptic excitatory transmission. U-69,593 decreased frequency, but not amplitude, of inhibitory synaptic currents, suggesting a presynaptic action. Multiphoton imaging of CeA-CRF neurons in rat brain slices showed that U-69,593 increased calcium signals evoked by electrical stimulation of presumed parabrachial input. This study shows for the first time that KOR activation increases activity of amygdala CRF neurons through synaptic disinhibition, resulting in averse-affective pain-like behaviors. Blocking KOR receptors may therefore represent a novel therapeutic strategy.
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Affiliation(s)
- Matthew Hein
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Guangchen Ji
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Dalton Tidwell
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Preston D'Souza
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Takaki Kiritoshi
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Vadim Yakhnitsa
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Edita Navratilova
- Department of Pharmacology, Arizona Health Sciences Center, University of Arizona, Tucson, AZ, USA
| | - Frank Porreca
- Department of Pharmacology, Arizona Health Sciences Center, University of Arizona, Tucson, AZ, USA
| | - Volker Neugebauer
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
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5
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Tavassoli M, Ardjmand A. Pentylenetetrazol and Morphine Interaction in a State-dependent Memory Model: Role of CREB Signaling. Basic Clin Neurosci 2021; 11:557-572. [PMID: 33613894 PMCID: PMC7878041 DOI: 10.32598/bcn.11.4.1482.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 09/20/2018] [Accepted: 10/15/2019] [Indexed: 11/20/2022] Open
Abstract
Introduction: State-dependent (STD) memory is a process, in which the learned information can be optimally retrieved only when the subject is in the state similar to the encoding phase. This phenomenon has been widely studied with morphine. Several studies have reported that Pentylenetetrazole (PTZ) impairs memory in experimental animal models. Due to certain mechanistic interactions between morphine and PTZ, it is hypothesized that PTZ may interfere with the morphine-STD. The cyclic adenosine monophosphate Response Element-Binding (CREB) is considered as the main downstream marker for long-term memory. This study was designed to determine the possible interaction between PTZ and morphine STD and the presumable changes in CREB mRNA. Methods: In an Inhibitory Avoidance (IA) model, posttraining morphine (2.5, 5, and 7.5 mg/ kg-i.p.) was used. The pre-test morphine was evaluated for morphine-induced STD memory. Moreover, the effect of a pre-test PTZ (60 mg/kg-i.p.) was studied along with morphine STD. Locomotion testing was carried out using open-field. Eventually, using real-time-PCR, the CREB mRNA changes in the hippocampus were evaluated. Results: Posttraining MOR (7.5 mg/kg-i.p.) impaired IA memory (P<0.001). The pre-test injection of similar doses of morphine recovered the morphine-induced memory impairment (P<0.001). The pre-test PTZ impaired the IA memory recall (P<0.001); however, the pre-test PTZ along with morphine STD potentiated the morphine-induced STD (P<0.001). Alterations in CREB mRNA were observed in all groups. No difference was seen in the locomotor activity. Conclusion: Presumably, the certain interactive effect of PTZ on morphine-induced STD is mediated through gamma-aminobutyric acid and opioid systems via CREB signaling.
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Affiliation(s)
- Marziyeh Tavassoli
- Institute for Basic Sciences, Physiology Research Center, Kashan University of Medical Sciences, Kashan, Iran
| | - Abolfazl Ardjmand
- Institute for Basic Sciences, Physiology Research Center, Kashan University of Medical Sciences, Kashan, Iran.,Department of Physiology, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran
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6
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Cell-Type Specificity of Neuronal Excitability and Morphology in the Central Amygdala. eNeuro 2021; 8:ENEURO.0402-20.2020. [PMID: 33188006 PMCID: PMC7877473 DOI: 10.1523/eneuro.0402-20.2020] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 10/12/2020] [Indexed: 02/08/2023] Open
Abstract
Central amygdala (CeA) neurons expressing protein kinase Cδ (PKCδ+) or somatostatin (Som+) differentially modulate diverse behaviors. The underlying features supporting cell-type-specific function in the CeA, however, remain unknown. Using whole-cell patch-clamp electrophysiology in acute mouse brain slices and biocytin-based neuronal reconstructions, we demonstrate that neuronal morphology and relative excitability are two distinguishing features between Som+ and PKCδ+ neurons in the laterocapsular subdivision of the CeA (CeLC). Som+ neurons, for example, are more excitable, compact, and with more complex dendritic arborizations than PKCδ+ neurons. Cell size, intrinsic membrane properties, and anatomic localization were further shown to correlate with cell-type-specific differences in excitability. Lastly, in the context of neuropathic pain, we show a shift in the excitability equilibrium between PKCδ+ and Som+ neurons, suggesting that imbalances in the relative output of these cells underlie maladaptive changes in behaviors. Together, our results identify fundamentally important distinguishing features of PKCδ+ and Som+ cells that support cell-type-specific function in the CeA.
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7
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κ Opioid Receptor-Dynorphin Signaling in the Central Amygdala Regulates Conditioned Threat Discrimination and Anxiety. eNeuro 2021; 8:ENEURO.0370-20.2020. [PMID: 33323398 PMCID: PMC7877472 DOI: 10.1523/eneuro.0370-20.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/29/2020] [Accepted: 11/24/2020] [Indexed: 02/07/2023] Open
Abstract
Neuropeptides within the central nucleus of the amygdala (CeA) potently modulate neuronal excitability and have been shown to regulate conditioned threat discrimination and anxiety. Here, we investigated the role of κ opioid receptor (KOR) and its endogenous ligand dynorphin in the CeA for regulation of conditioned threat discrimination and anxiety-like behavior in mice. We demonstrate that reduced KOR expression through genetic inactivation of the KOR encoding gene, Oprk1, in the CeA results in increased anxiety-like behavior and impaired conditioned threat discrimination. In contrast, reduction of dynorphin through genetic inactivation of the dynorphin encoding gene, Pdyn, in the CeA has no effect on anxiety or conditioned threat discrimination. However, inactivation of Pdyn from multiple sources, intrinsic and extrinsic to the CeA phenocopies Oprk1 inactivation. These findings suggest that dynorphin inputs to the CeA signal through KOR to promote threat discrimination and dampen anxiety.
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8
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Zarrindast MR, Khakpai F. State-dependent memory and its modulation by different brain areas and neurotransmitters. EXCLI JOURNAL 2020; 19:1081-1099. [PMID: 33013265 PMCID: PMC7527511 DOI: 10.17179/excli2020-2612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 07/27/2020] [Indexed: 11/10/2022]
Abstract
The state-dependent memory defines as a state that the retrieval of recently obtained information may be potential if the subject exists in a similar physiological situation as for the period of the encoding stage. Studies revealed that exogenous and endogenous compounds could induce state-dependent memory. The state-dependent memory made it probable to differentiate the effects of drugs per se on learning from the effects due to alterations in drug state during the task. Studies proposed the role of regions beyond the limbic formation and illustrated that state-dependent memory produced by various neurotransmitter systems and pharmacological compounds. Our review of the literature revealed that: (a) re-administration of drugs on the same state induce state-dependent memory; (b) many neurotransmitters induce endogenous state-dependent memory; (c) there are cross state-dependent learning and memory between some drugs; (d) some sites of the brain including the CA1 areas of the hippocampus, central nucleus of the amygdala (CeA), septum, ventral tegmental area (VTA), and nucleus accumbens (NAC) are involved in state-dependent memory. See also Figure 1(Fig. 1).
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Affiliation(s)
- Mohammad-Reza Zarrindast
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Khakpai
- Cognitive and Neuroscience Research Center (CNRC), Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
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9
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Ji G, Neugebauer V. Kappa opioid receptors in the central amygdala modulate spinal nociceptive processing through an action on amygdala CRF neurons. Mol Brain 2020; 13:128. [PMID: 32948219 PMCID: PMC7501648 DOI: 10.1186/s13041-020-00669-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/09/2020] [Indexed: 12/11/2022] Open
Abstract
The amygdala plays an important role in the emotional-affective aspects of behaviors and pain, but can also modulate sensory aspect of pain ("nociception"), likely through coupling to descending modulatory systems. Here we explored the functional coupling of the amygdala to spinal nociception. We found that pharmacological activation of neurons in the central nucleus of the amygdala (CeA) increased the activity of spinal dorsal horn neurons; and this effect was blocked by optogenetic silencing of corticotropin releasing factor (CRF) positive CeA neurons. A kappa opioid receptor (KOR) agonist (U-69,593) was administered into the CeA by microdialysis. KOR was targeted because of their role in averse-affective behaviors through actions in limbic brain regions. Extracellular single-unit recordings were made of CeA neurons or spinal dorsal horn neurons in anesthetized transgenic Crh-Cre rats. Neurons responded more strongly to noxious than innocuous stimuli. U-69,593 increased the responses of CeA and spinal neurons to innocuous and noxious mechanical stimulation of peripheral tissues. The facilitatory effect of the agonist was blocked by optical silencing of CRF-CeA neurons though light activation of halorhodopsin expressed in these neurons by viral-vector. The CRF system in the amygdala has been implicated in aversiveness and pain modulation. The results suggest that the amygdala can modulate spinal nociceptive processing in a positive direction through CRF-CeA neurons and that KOR activation in the amygdala (CeA) has pro-nociceptive effects.
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Affiliation(s)
- Guangchen Ji
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, School of Medicine, 3601 4th St, Lubbock, TX, 79430-6592, USA
- Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Volker Neugebauer
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, School of Medicine, 3601 4th St, Lubbock, TX, 79430-6592, USA.
- Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
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10
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Affiliation(s)
- Marlene A Wilson
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, United States
- Columbia VA Health Care System, Columbia, SC, United States
| | - Alexander J McDonald
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, United States
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11
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Kissiwaa SA, Patel SD, Winters BL, Bagley EE. Opioids differentially modulate two synapses important for pain processing in the amygdala. Br J Pharmacol 2020; 177:420-431. [PMID: 31596498 PMCID: PMC6989950 DOI: 10.1111/bph.14877] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 08/04/2019] [Accepted: 08/09/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Pain is a subjective experience involving sensory discriminative and emotionally aversive components. Consistent with its role in pain processing and emotions, the amygdala modulates the aversive component of pain. The laterocapsular region of the central nucleus of the amygdala (CeLC) receives nociceptive information from the parabrachial nucleus (PB) and polymodal, including nociceptive, inputs from the basolateral nucleus of the amygdala (BLA). Opioids are strong analgesics and reduce both the sensory discriminative and the affective component of pain. However, it is unknown whether opioids regulate activity at the two nociceptive inputs to the amygdala. EXPERIMENTAL APPROACH Using whole-cell electrophysiology, optogenetics, and immunohistochemistry, we investigated whether opioids inhibit the rat PB-CeLC and BLA-CeLC synapses. KEY RESULTS Opioids inhibited glutamate release at the PB-CeLC and BLA-CeLC synapses. Opioid inhibition is via the μ-receptor at the PB-CeLC synapse, while at the BLA-CeLC synapse, inhibition is via μ-receptors in all neurons and via δ-receptors and κ-receptors in a subset of neurons. CONCLUSIONS AND IMPLICATIONS Agonists of μ-receptors inhibited two of the synaptic inputs carrying nociceptive information into the laterocapsular amygdala. Therefore, μ-receptor agonists, such as morphine, will inhibit glutamate release from PB and BLA in the CeLC, and this could serve as a mechanism through which opioids reduce the affective component of pain and pain-induced associative learning. The lower than expected regulation of BLA synaptic outputs by δ-receptors does not support the proposal that opioid receptor subtypes segregate into subnuclei of brain regions.
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MESH Headings
- Amygdala/drug effects
- Amygdala/metabolism
- Amygdala/physiopathology
- Analgesics, Opioid/pharmacology
- Animals
- Glutamic Acid/metabolism
- Male
- Neural Inhibition/drug effects
- Nociception/drug effects
- Nociceptive Pain/metabolism
- Nociceptive Pain/physiopathology
- Nociceptive Pain/prevention & control
- Optogenetics
- Pain Perception/drug effects
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/metabolism
- Synapses/drug effects
- Synapses/metabolism
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Affiliation(s)
- Sarah A. Kissiwaa
- Discipline of Pharmacology and Charles Perkins CentreThe University of SydneySydneyNSWAustralia
| | - Sahil D. Patel
- Discipline of Pharmacology and Charles Perkins CentreThe University of SydneySydneyNSWAustralia
| | - Bryony L. Winters
- Pain Management Research Institute, Kolling Institute of Medical ResearchThe University of Sydney, Royal North Shore HospitalSt LeonardsNSWAustralia
| | - Elena E. Bagley
- Discipline of Pharmacology and Charles Perkins CentreThe University of SydneySydneyNSWAustralia
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12
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Puryear CB, Brooks J, Tan L, Smith K, Li Y, Cunningham J, Todtenkopf MS, Dean RL, Sanchez C. Opioid receptor modulation of neural circuits in depression: What can be learned from preclinical data? Neurosci Biobehav Rev 2020; 108:658-678. [DOI: 10.1016/j.neubiorev.2019.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 12/14/2022]
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13
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Fu Y, Depue RA. A novel neurobehavioral framework of the effects of positive early postnatal experience on incentive and consummatory reward sensitivity. Neurosci Biobehav Rev 2019; 107:615-640. [DOI: 10.1016/j.neubiorev.2019.09.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 09/08/2019] [Accepted: 09/17/2019] [Indexed: 12/22/2022]
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14
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Carrero JP, Kaigler KF, Hartshorn GH, Fadel JR, Wilson MA. Mu opioid receptor regulation of glutamate efflux in the central amygdala in response to predator odor. Neurobiol Stress 2019; 11:100197. [PMID: 31832510 PMCID: PMC6888766 DOI: 10.1016/j.ynstr.2019.100197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/23/2019] [Accepted: 10/09/2019] [Indexed: 12/24/2022] Open
Abstract
The amygdala plays an important role in the responses to predator threat. Glutamatergic processes in amygdala regulate the behavioral responses to predator stress, and we have found that exposure to ferret odor activates glutamatergic neurons of the basolateral amygdala [BLA] which are known to project to the central amygdala [CeA]. Therefore, we tested if predator stress would increase glutamate release in the rat CeA using in vivo microdialysis, while monitoring behavioral responses during a 1 h exposure to ferret odor. Since injections of mu opioid receptor [MOR] agonists and antagonists into the CeA modulate behavioral responses to predator odor, we locally infused the MOR agonist DAMGO or the MOR antagonist CTAP into the CeA during predator stress to examine effects on glutamate efflux and behavior. We found that ferret odor exposure increased glutamate, but not GABA, efflux in the CeA, and this effect was attenuated by tetrodotoxin. Interestingly, increases in glutamate efflux elicited by ferret odor exposure were blocked by infusion of CTAP, but CTAP did not alter the behavioral responses during predator stress. DAMGO alone enhanced glutamate efflux, but did not modulate glutamate efflux during predator stress. These studies demonstrate that ferret odor exposure, like other stressors, enhances glutamate efflux in the CeA. Further, they suggest that activation of MOR in the CeA may help shape the defensive response to predator odor and other threats. Predator odor stress increased glutamate efflux in the central amygdala. Predator stress-induced increases in glutamate were blocked by a mu opioid receptor antagonist. Blocking glutamate efflux in the amygdala did not alter behavioral responses to predator odor. Infusion of a mu opioid receptor agonist also increased glutamate efflux in the central amygdala.
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Affiliation(s)
- Jeffrey Parrilla Carrero
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29208, USA.,Columbia VA Health Care System, Columbia, SC, 29209, USA
| | - Kris F Kaigler
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29208, USA.,Columbia VA Health Care System, Columbia, SC, 29209, USA
| | - George H Hartshorn
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29208, USA.,Columbia VA Health Care System, Columbia, SC, 29209, USA
| | - Jim R Fadel
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29208, USA.,Columbia VA Health Care System, Columbia, SC, 29209, USA
| | - Marlene A Wilson
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, 29208, USA.,Columbia VA Health Care System, Columbia, SC, 29209, USA
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15
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Pedrón VT, Varani AP, Bettler B, Balerio GN. GABA B receptors modulate morphine antinociception: Pharmacological and genetic approaches. Pharmacol Biochem Behav 2019; 180:11-21. [PMID: 30851293 DOI: 10.1016/j.pbb.2019.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 02/28/2019] [Accepted: 02/28/2019] [Indexed: 10/27/2022]
Abstract
Previous studies in our laboratory showed an interaction between the GABAergic and opioid systems involved in the analgesic effect of baclofen (BAC). Furthermore, it is known that sex differences exist regarding various pharmacological responses of morphine (MOR) and they are related to an increased sensitivity to MOR effects in males. The aims of the present study were to evaluate the possible involvement of the GABAB receptors in the antinociceptive responses induced by MOR (1, 3 and 9 mg/kg, s.c.) administration using both pharmacological (BAC 2 mg/kg, i.p.; and 2-OH-saclofen, SAC 0.3 mg/kg, intra cisterna magna) and genetic approaches (GABAB1 knockout mice; GABAB1 KO) in mice of both sexes. In addition, we explored the alterations in c-Fos expression of different brain areas involved in the antinociceptive effect of MOR using both approaches. The pharmacological approach showed a higher dose-dependent antinociceptive effect of MOR in male mice compared to female mice. BAC and SAC pretreatment potentiated and attenuated the antinociceptive effect of MOR, respectively, in both sexes. The genetic approach revealed a dose-dependent antinociceptive effect of MOR in the wild type mice, but not in the GABAB1 KO mice and no sex differences were observed. Additionally, BAC and SAC pretreatment and the lack of GABAB1 subunit of the GABAB receptor prevented the changes observed in c-Fos expression in the cingulate cortex and nucleus accumbens of male mice. Our results suggest that the GABAB receptors are involved in the MOR antinociceptive effect of both male and female mice.
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Affiliation(s)
- Valeria T Pedrón
- CONICET - Universidad de Buenos Aires, Instituto de Investigaciones Farmacológicas (ININFA), Buenos Aires, Argentina
| | - Andrés P Varani
- CONICET - Universidad de Buenos Aires, Instituto de Investigaciones Farmacológicas (ININFA), Buenos Aires, Argentina
| | - Bernhard Bettler
- Department of Biomedicine, Institute of Physiology, Pharmazentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Graciela N Balerio
- CONICET - Universidad de Buenos Aires, Instituto de Investigaciones Farmacológicas (ININFA), Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Farmacología, Buenos Aires, Argentina.
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Dhull DK, Kumar A. Tramadol ameliorates behavioural, biochemical, mitochondrial and histological alterations in ICV-STZ-induced sporadic dementia of Alzheimer's type in rats. Inflammopharmacology 2017; 26:925-938. [PMID: 29249049 DOI: 10.1007/s10787-017-0431-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 12/06/2017] [Indexed: 12/23/2022]
Abstract
Alzheimer disease represents a major public health issue with limited therapeutic interventions. We explored the possibility of therapeutic approach by repurposing of tramadol in a sporadic animal model of Alzheimer's type. Streptozocin (STZ 3 mg/kg; bilaterally) was injected to male SD rats through intracerebroventricular (ICV) route. Drug treatment was started just after streptozocin administration and continued for 3 weeks. The rats were killed on the 21st day following the last behavioral test, and cytoplasmic fractions of the hippocampus and pre-frontal cortex were prepared for the quantification of acetylcholinesterase, oxidative stress parameter, mitochondrial enzymes activity and histological examination. Tramadol (5, 10 and 20 mg/kg, i.p.) was used as a treatment drug, and memantine (10 mg/kg, i.p.) was used as a standard. Tramadol significantly attenuated behavioral, biochemical, mitochondrial and histological alterations at low (5 mg/kg) and intermediate (10 mg/kg) dose, suggesting its neuroprotective potential in ICV-STZ-treated rats. Further, the neuroprotective effect of tramadol (10 mg/kg) was comparable to memantine (10 mg/kg). In conclusion, our results indicate the effectiveness of tramadol in preventing ICV-STZ-induced cognitive impairment as well as mito-oxidative stress. Further, these findings reveal the possibility of MOR agonist as a therapeutic approach for sporadic Alzheimer disease.
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Affiliation(s)
- Dinesh K Dhull
- Pharmacology Division, University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Study (UGC-CAS), Panjab University, Chandigarh, 160014, India
| | - Anil Kumar
- Pharmacology Division, University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Study (UGC-CAS), Panjab University, Chandigarh, 160014, India.
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Yan JB, Hu ZH. [µ-opioid receptors in the central nucleus of the amygdala mediate sodium intake in rats]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2017; 37:1195-1200. [PMID: 28951361 PMCID: PMC6765484 DOI: 10.3969/j.issn.1673-4254.2017.09.09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Indexed: 06/07/2023]
Abstract
OBJECTIVE To investigate the opioidergic mechanism of the central nucleus of the amygdala (CeA) for regulating sodium appetite in rats. METHDOS Using the elaborate invasive cerebral cannulation and brain microinjection method, we observed the effects of bilateral intra-CeA injections of DAMGO (a selective µ-opioid receptor agonist) and CTAP (a highly selective µ-opioid receptor antagonist), either alone or in combination, on NaCl solution (0.3 mol/L) and water intake by rats in different models of Na+ ingestion. RESULTS In the two-bottle tests, bilateral injections of DAMGO at 1, 2, and 4 nmol into the CeA induced a dose-related increase of NaCl and water intake in rats treated with water deprivation with partial rehydration (WD-PR), and pretreatment with 0.5, 1, and 2 nmol CTAP injected into the CeA significantly suppressed DAMGO-induced NaCl and water intake in a dose-dependent manner: in the one-bottle tests, bilateral injections of DAMGO (2 noml) into the CeA had no effect on water intake of the rats. In rats with subcutaneous injection of furosemide (FURO) combined with captopril (CAP) (FURO+CAP), bilateral intra-CeA injections of DAMGO (2 nmol) caused increased NaCl and water intake in the two-bottle tests, but such effects were suppressed by pretreatment with CTAP injection into the CeA; in the one-bottle tests, bilateral intra-CeA injections of DAMGO had no effect on water intake of the rats. CONCLUSION µ-opioid receptors in the CeA are involved in the excitatory regulation of sodium appetite to mediate sodium intake. µ-opioid receptor antagonists are expected to be targets for developing inhibitors of sodium appetite.
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Affiliation(s)
- Jun-Bao Yan
- Department of Physiology, Medical College of Henan University of Science and Technology, Luoyang 471023, China.E-mail:
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18
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Enkephalins: Endogenous Analgesics with an Emerging Role in Stress Resilience. Neural Plast 2017; 2017:1546125. [PMID: 28781901 PMCID: PMC5525068 DOI: 10.1155/2017/1546125] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/15/2017] [Accepted: 05/24/2017] [Indexed: 12/20/2022] Open
Abstract
Psychological stress is a state of mental or emotional strain or tension that results from adverse or demanding circumstances. Chronic stress is well known to induce anxiety disorders and major depression; it is also considered a risk factor for Alzheimer's disease. Stress resilience is a positive outcome that is associated with preserved cognition and healthy aging. Resilience presents psychological and biological characteristics intrinsic to an individual conferring protection against the development of psychopathologies in the face of adversity. How can we promote or improve resilience to chronic stress? Numerous studies have proposed mechanisms that could trigger this desirable process. The roles of enkephalin transmission in the control of pain, physiological functions, like respiration, and affective disorders have been studied for more than 30 years. However, their role in the resilience to chronic stress has received much less attention. This review presents the evidence for an emerging involvement of enkephalin signaling through its two associated opioid receptors, μ opioid peptide receptor and δ opioid peptide receptor, in the natural adaptation to stressful lifestyles.
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Differential effects of naloxone on rewarding electrical stimulation of the central nucleus of the amygdala and parabrachial complex in a place preference study. Brain Res Bull 2016; 124:182-9. [PMID: 27173444 DOI: 10.1016/j.brainresbull.2016.04.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 04/11/2016] [Accepted: 04/28/2016] [Indexed: 12/29/2022]
Abstract
The central nucleus of the amygdala (CeA) is considered to be involved in different affective, sensory, regulatory, and acquisition processes. This study analyzed whether electrical stimulation of the PB-CeA system induces preferences in a concurrent place preference (cPP) task, as observed after stimulation of the parabrachial-insular cortex (PB-IC) axis. It also examined whether the rewarding effects are naloxone-dependent. The results show that electrical stimulation of the CeA and external lateral parabrachial subnucleus (LPBe) induces consistent preference behaviors in a cPP task. However, subcutaneous administration of an opiate antagonist (naloxone; 4mg/ml/kg) blocked the rewarding effect of the parabrachial stimulation but not that of the amygdala stimulation. These results are interpreted in the context of multiple brain reward systems that appear to differ both anatomically and neurochemically, notably with respect to the opiate system.
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20
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Maire JJ, Close LN, Heinricher MM, Selden NR. Distinct pathways for norepinephrine- and opioid-triggered antinociception from the amygdala. Eur J Pain 2016; 20:206-14. [PMID: 25847835 PMCID: PMC4593714 DOI: 10.1002/ejp.708] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND The amygdala has an important role in pain and pain modulation. We showed previously in animal studies that α2 -adrenoreceptor activation in the central nucleus of the amygdala (CeA) mediates hypoalgesia produced by restraint stress, and that direct application of an α2 -agonist in this region produces analgesia. AIMS In the present animal experiments, we investigated the pathways through which α2 -sensitive systems in the CeA produce behavioural analgesia. The CeA has dense connections to a descending pain modulatory network, centred in the midbrain periaqueductal grey (PAG) and the rostral ventromedial medulla (RVM), which is implicated in various forms of stress-related hypoalgesia and which mediates the antinociceptive effect of morphine applied in the basolateral amygdala. We investigated whether this circuit mediates the hypoalgesic effects of α2 -adrenergic agonist administration into the CeA as well as the contribution of endogenous opioids and cannabinoids. We also tested the possibility that activation of α2 -receptors in the CeA produces antinociception by recruitment of noradrenergic pathways projecting to the spinal cord. RESULTS Hypoalgesia resulting from bilateral application of the α2 -adrenergic agonist clonidine in the CeA was not reversed by chemical inactivation of the RVM or by systemic injections of naloxone (μ-opioid antagonist) or rimonabant (CB1 antagonist). By contrast, spinal α2 -receptor blockade (intrathecal idazoxan) completely prevented the hypoalgesic effect of clonidine in the CeA, and unmasked a small but significant hyperalgesia. CONCLUSION In rats, adrenergic actions in the CeA mediating hypoalgesia require spinal adrenergic neurotransmission but not the PAG-RVM pain modulatory network, or opiate or cannabinoid systems.
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Affiliation(s)
- J J Maire
- Department of Neurological Surgery, Oregon Health & Science University, Portland, USA
| | - L N Close
- Department of Neurological Surgery, Oregon Health & Science University, Portland, USA
| | - M M Heinricher
- Department of Neurological Surgery, Oregon Health & Science University, Portland, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, USA
| | - N R Selden
- Department of Neurological Surgery, Oregon Health & Science University, Portland, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, USA
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Chan P, Lutfy K. Molecular Changes in Opioid Addiction: The Role of Adenylyl Cyclase and cAMP/PKA System. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 137:203-27. [PMID: 26810003 DOI: 10.1016/bs.pmbts.2015.10.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
For centuries, opiate analgesics have had a considerable presence in the treatment of moderate to severe pain. While effective in providing analgesia, opiates are notorious in exerting many undesirable adverse reactions. The receptor targets and the intracellular effectors of opioids have largely been identified. Furthermore, much of the mechanisms underlying the development of tolerance, dependence, and withdrawal have been delineated. Thus, there is a focus on developing novel compounds or strategies in mitigating or avoiding the development of tolerance, dependence, and withdrawal. This review focuses on the adenylyl cyclase and cyclic adenosine 3,5-monophosphate (cAMP)/protein kinase A (AC/cAMP/PKA) system as the central player in mediating the acute and chronic effects of opioids. This chapter also reviews the neuronal adaptive changes in the locus coeruleus, amygdala, periaqueductal gray, and ventral tegmental area induced by acute and chronic actions of opioid because these neuronal adaptive changes in these regions may underlie the behavioral changes observed in opiate users and abusers.
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Affiliation(s)
- Patrick Chan
- Department of Pharmacy and Pharmacy Administration, Western University of Health Sciences, College of Pharmacy, Pomona, California, USA.
| | - Kabirullah Lutfy
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, USA
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22
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μ-Opioid Receptor-Mediated Inhibition of Intercalated Neurons and Effect on Synaptic Transmission to the Central Amygdala. J Neurosci 2015; 35:7317-25. [PMID: 25972162 DOI: 10.1523/jneurosci.0204-15.2015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The amygdala is a key region for the processing of information underlying fear, anxiety, and fear extinction. Within the local neuronal networks of the amygdala, a population of inhibitory, intercalated neurons (ITCs) modulates the flow of information among various nuclei of amygdala, including the basal nucleus (BA) and the centromedial nucleus (CeM) of the amygdala. These ITCs have been shown to be important during fear extinction and are target of a variety of neurotransmitters and neuropeptides. Here we provide evidence that the activation of μ-opioid receptors (MORs) by the specific agonist DAMGO ([D-Ala2,N-Me-Phe4,Gly5-ol]-Enkephalin) hyperpolarizes medially located ITCs (mITCs) in acute brain slices of mice. Moreover, we use whole-cell patch-clamp recordings in combination with local electrical stimulation or glutamate uncaging to analyze the effect of MOR activation on local microcircuits. We show that the GABAergic transmission between mITCs and CeM neurons is attenuated by DAMGO, whereas the glutamatergic transmission on CeM neurons and mITCs is unaffected. Furthermore, MOR activation induced by theta burst stimulation in BA suppresses plastic changes of feedforward inhibitory transmission onto CeM neurons as revealed by the MOR antagonist CTAP d-Phe-Cys-Tyr-d-Trp-Arg-Thr-Pen-Thr-NH2. In summary, the mITCs constitute a target for the opioid system, and therefore, the activation of MOR in ITCs might play a central role in the modulation of the information processing between the basolateral complex of the amygdala and central nuclei of the amygdala.
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Abstract
A limbic brain area, the amygdala plays a key role in emotional responses and affective states and disorders such as learned fear, anxiety, and depression. The amygdala has also emerged as an important brain center for the emotional-affective dimension of pain and for pain modulation. Hyperactivity in the laterocapsular division of the central nucleus of the amygdala (CeLC, also termed the "nociceptive amygdala") accounts for pain-related emotional responses and anxiety-like behavior. Abnormally enhanced output from the CeLC is the consequence of an imbalance between excitatory and inhibitory mechanisms. Impaired inhibitory control mediated by a cluster of GABAergic interneurons in the intercalated cell masses (ITC) allows the development of glutamate- and neuropeptide-driven synaptic plasticity of excitatory inputs from the brainstem (parabrachial area) and from the lateral-basolateral amygdala network (LA-BLA, site of integration of polymodal sensory information). BLA hyperactivity also generates abnormally enhanced feedforward inhibition of principal cells in the medial prefrontal cortex (mPFC), a limbic cortical area that is strongly interconnected with the amygdala. Pain-related mPFC deactivation results in cognitive deficits and failure to engage cortically driven ITC-mediated inhibitory control of amygdala processing. Impaired cortical control allows the uncontrolled persistence of amygdala pain mechanisms.
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Affiliation(s)
- Volker Neugebauer
- Department of Pharmacology and Neuroscience, Center for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX, 79430-6592, USA,
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24
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Hayes DJ, Duncan NW, Xu J, Northoff G. A comparison of neural responses to appetitive and aversive stimuli in humans and other mammals. Neurosci Biobehav Rev 2014; 45:350-68. [PMID: 25010558 DOI: 10.1016/j.neubiorev.2014.06.018] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 04/29/2014] [Accepted: 06/27/2014] [Indexed: 11/30/2022]
Abstract
Distinguishing potentially harmful or beneficial stimuli is necessary for the self-preservation and well-being of all organisms. This assessment requires the ongoing valuation of environmental stimuli. Despite much work on the processing of aversive- and appetitive-related brain signals, it is not clear to what degree these two processes interact across the brain. To help clarify this issue, this report used a cross-species comparative approach in humans (i.e. meta-analysis of imaging data) and other mammals (i.e. targeted review of functional neuroanatomy in rodents and non-human primates). Human meta-analysis results suggest network components that appear selective for appetitive (e.g. ventromedial prefrontal cortex, ventral tegmental area) or aversive (e.g. cingulate/supplementary motor cortex, periaqueductal grey) processing, or that reflect overlapping (e.g. anterior insula, amygdala) or asymmetrical, i.e. apparently lateralized, activity (e.g. orbitofrontal cortex, ventral striatum). However, a closer look at the known value-related mechanisms from the animal literature suggests that all of these macroanatomical regions are involved in the processing of both appetitive and aversive stimuli. Differential spatiotemporal network dynamics may help explain similarities and differences in appetitive- and aversion-related activity.
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Affiliation(s)
- Dave J Hayes
- Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, 1145 Carling Avenue, Ottawa, Canada; Toronto Western Research Institute, Brain, Imaging and Behaviour - Systems Neuroscience, University of Toronto, Division of Neurosurgery, 399 Bathurst Street, Toronto, Canada.
| | - Niall W Duncan
- Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, 1145 Carling Avenue, Ottawa, Canada; Department of Biology, University of Carleton, 1125 Colonel By Drive, Ottawa, Canada; Centre for Cognition and Brain Disorders, Hangzhou Normal University, 276 Lishui Lu, Hangzhou, China
| | - Jiameng Xu
- Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, 1145 Carling Avenue, Ottawa, Canada
| | - Georg Northoff
- Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, 1145 Carling Avenue, Ottawa, Canada; Centre for Cognition and Brain Disorders, Hangzhou Normal University, 276 Lishui Lu, Hangzhou, China; Taipei Medical University, Shuang Ho Hospital, Brain and Consciousness Research Center, Graduate Institute of Humanities in Medicine, Taipei, Taiwan; National Chengchi University, Research Center for Mind, Brain and Learning, Taipei, Taiwan
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25
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Bajo M, Madamba SG, Roberto M, Siggins GR. Acute morphine alters GABAergic transmission in the central amygdala during naloxone-precipitated morphine withdrawal: role of cyclic AMP. Front Integr Neurosci 2014; 8:45. [PMID: 24926240 PMCID: PMC4044973 DOI: 10.3389/fnint.2014.00045] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Accepted: 05/14/2014] [Indexed: 01/23/2023] Open
Abstract
The central amygdala (CeA) plays an important role in opioid addiction. Therefore, we examined the effects of naloxone-precipitated morphine withdrawal (WD) on GABAergic transmission in rat CeA neurons using whole-cell recordings with naloxone in the bath. The basal frequency of miniature inhibitory postsynaptic currents (mIPSCs) increased in CeA neurons from WD compared to placebo rats. Acute morphine (10 μ M) had mixed effects (≥20% change from baseline) on mIPSCs in placebo and WD rats. In most CeA neurons (64%) from placebo rats, morphine significantly decreased mIPSC frequency and amplitude. In 32% of placebo neurons, morphine significantly increased mIPSC amplitudes but had no effect on mIPSC frequency. In WD rats, acute morphine significantly increased mIPSC frequency but had no effect on mIPSC amplitude in 41% of CeA neurons. In 45% of cells, acute morphine significantly decreased mIPSC frequency and amplitude. Pre-treatment with the cyclic AMP inhibitor (R)-adenosine, cyclic 3',5'-(hydrogenphosphorothioate) triethylammonium (RP), prevented acute morphine-induced potentiation of mIPSCs. Pre-treatment of slices with the Gi/o G-protein subunit inhibitor pertussis toxin (PTX) did not prevent the acute morphine-induced enhancement or inhibition of mIPSCs. PTX and RP decreased basal mIPSC frequencies and amplitudes only in WD rats. The results suggest that inhibition of GABAergic transmission in the CeA by acute morphine is mediated by PTX-insensitive mechanisms, although PTX-sensitive mechanisms cannot be ruled out for non-morphine responsive cells; by contrast, potentiation of GABAergic transmission is mediated by activated cAMP signaling that also mediates the increased basal GABAergic transmission in WD rats. Our data indicate that during the acute phase of WD, the CeA opioid and GABAergic systems undergo neuroadaptative changes conditioned by a previous chronic morphine exposure and dependence.
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Affiliation(s)
- Michal Bajo
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute La Jolla, CA, USA
| | - Samuel G Madamba
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute La Jolla, CA, USA
| | - Marisa Roberto
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute La Jolla, CA, USA
| | - George R Siggins
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute La Jolla, CA, USA
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Bérubé P, Poulin JF, Laforest S, Drolet G. Enkephalin knockdown in the basolateral amygdala reproduces vulnerable anxiety-like responses to chronic unpredictable stress. Neuropsychopharmacology 2014; 39:1159-68. [PMID: 24213354 PMCID: PMC3957109 DOI: 10.1038/npp.2013.316] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/16/2013] [Accepted: 10/18/2013] [Indexed: 12/29/2022]
Abstract
The endogenous enkephalins (ENKs) are potential candidates participating in the naturally occurring variations in coping styles and determining the individual capacities for adaptation during chronic stress exposure. Here we demonstrate that there is a large variance in individual behavioral, as well as in physiological outcomes, in a population of Sprague-Dawley rats subjected to 3 weeks of chronic unpredictable stress (CUS). Separation of resilient and vulnerable subpopulations reveals specific long-term neuroadaptation in the ENKergic brain circuits. ENK mRNA expression was greatly reduced in the posterior basolateral nucleus of amygdala (BLAp) in vulnerable individuals. In contrast, ENK mRNA levels were similar in resilient and control (unstressed) individuals. Another group of rats were used for lentiviral-mediated knockdown of ENK to assess whether a decrease of ENK expression in the BLAp reproduces the behavioral disturbances found in vulnerable individuals. ENK knockdown specifically located in the BLAp was sufficient to increase anxiety in the behavioral tests, such as social interaction and elevated plus maze when compared with control individuals. These results show that specific neuroadaptation mediated by the ENKergic neurotransmission in the BLAp is a key regulator of resilience, whereas a decrease of the ENK in the BLAp is a maladaptation mechanism, which mediates the behavioral dichotomy observed between vulnerable and resilient following 3 weeks of CUS.
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Affiliation(s)
- Patrick Bérubé
- Centre de recherche du CHU de Québec, Axe Neurosciences, Université Laval, Quebec, QC, Canada
| | - Jean-François Poulin
- Centre de recherche du CHU de Québec, Axe Neurosciences, Université Laval, Quebec, QC, Canada
| | - Sylvie Laforest
- Centre de recherche du CHU de Québec, Axe Neurosciences, Université Laval, Quebec, QC, Canada
| | - Guy Drolet
- Centre de recherche du CHU de Québec, Axe Neurosciences, Université Laval, Quebec, QC, Canada,Centre de recherche du CHU de Québec, Axe Neurosciences, Université Laval, CHUL P-09800, 2705 Laurier, Québec, QC, Canada G1V 4G2. Tel: +418 525 4444, ext. 47979, Fax: +418 654 2753, E-mail:
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27
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Yan JB, Sun HL, Wang Q, Chen K, Sun B, Song L, Yan W, Zhao XL, Zhao SR, Zhang Y, Qiao H, Hu B, Yan JQ. Natriorexigenic effect of DAMGO is decreased by blocking AT1 receptors in the central nucleus of the amygdala. Neuroscience 2013; 262:9-20. [PMID: 24389419 DOI: 10.1016/j.neuroscience.2013.12.046] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 12/20/2013] [Accepted: 12/21/2013] [Indexed: 11/17/2022]
Abstract
μ-Opioid receptor (μ-OR) activation with agonist [D-Ala², N-Me-Phe⁴, Gly⁵-ol]-enkephalin (DAMGO) in the central nucleus of the amygdala (CeA) induces sodium (0.3M NaCl) intake in rats. The purpose of this study was to examine the effects of pre-injections of losartan (AT1 angiotensin receptor antagonist) into the CeA on 0.3 M NaCl and water intake induced by DAMGO injected bilaterally in the same area in rats submitted to water deprivation-partial rehydration (WD-PR) and in rats treated with the diuretic furosemide (FURO) combined with a low dose of the angiotensin-converting enzyme inhibitor captopril (CAP) injected subcutaneously (FURO/CAP). Male Sprague-Dawley rats with stainless steel cannulas implanted bilaterally into the CeA were used. In WD-PR rats, bilateral injections of DAMGO (2 nmol in 0.5 μL) into the CeA induced 0.3 M NaCl and water intake, and pre-treatment with losartan (108 nmol in 0.5 μL) injected into the CeA reduced 0.3 M NaCl and water intake induced by DAMGO. In FURO/CAP rats, pre-treatment with losartan (108 nmol in 0.5 μL) injected into the CeA attenuated the increase in 0.3M NaCl and water intake induced by DAMGO (2 nmol in 0.5 μL) injected into the same site. The results suggest that the natriorexigenic effect of DAMGO injected into the CeA is facilitated by endogenous angiotensin II acting on AT1 receptors in the CeA, which drives rats to ingest large amounts of hypertonic NaCl.
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Affiliation(s)
- J-B Yan
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China; Department of Physiology, Medical College of Henan University of Science and Technology, 263# Kaiyuan Avenue, Luoyang, Henan 471023, PR China
| | - H-L Sun
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China; Department of Oral Biology, Xi'an Jiaotong University College of Stomatology, 98# Xiwu Road, Xi'an, Shaanxi 710004, PR China
| | - Q Wang
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - K Chen
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - B Sun
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - L Song
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - W Yan
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - X-L Zhao
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - S-R Zhao
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - Y Zhang
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - H Qiao
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - B Hu
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China
| | - J-Q Yan
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China; Department of Oral Biology, Xi'an Jiaotong University College of Stomatology, 98# Xiwu Road, Xi'an, Shaanxi 710004, PR China.
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28
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Stuth EAE, Stucke AG, Zuperku EJ. Effects of anesthetics, sedatives, and opioids on ventilatory control. Compr Physiol 2013; 2:2281-367. [PMID: 23720250 DOI: 10.1002/cphy.c100061] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This article provides a comprehensive, up to date summary of the effects of volatile, gaseous, and intravenous anesthetics and opioid agonists on ventilatory control. Emphasis is placed on data from human studies. Further mechanistic insights are provided by in vivo and in vitro data from other mammalian species. The focus is on the effects of clinically relevant agonist concentrations and studies using pharmacological, that is, supraclinical agonist concentrations are de-emphasized or excluded.
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Affiliation(s)
- Eckehard A E Stuth
- Medical College of Wisconsin, Anesthesia Research Service, Zablocki VA Medical Center, Milwaukee, Wisconsin, USA.
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29
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Gilpin NW, Roberto M, Koob GF, Schweitzer P. Kappa opioid receptor activation decreases inhibitory transmission and antagonizes alcohol effects in rat central amygdala. Neuropharmacology 2013; 77:294-302. [PMID: 24157490 DOI: 10.1016/j.neuropharm.2013.10.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 09/19/2013] [Accepted: 10/08/2013] [Indexed: 12/30/2022]
Abstract
Activation of the kappa opioid receptor (KOR) system mediates negative emotional states and considerable evidence suggests that KOR and their natural ligand, dynorphin, are involved in ethanol dependence and reward. The central amygdala (CeA) plays a major role in alcohol dependence and reinforcement. Dynorphin peptide and gene expression are activated in the amygdala during acute and chronic administration of alcohol, but the effects of activation or blockade of KOR on inhibitory transmission and ethanol effects have not been studied. We used the slice preparation to investigate the physiological role of KOR and interaction with ethanol on GABA(A) receptor-mediated synaptic transmission. Superfusion of dynorphin or U69593 onto CeA neurons decreased evoked inhibitory postsynaptic potentials (IPSPs) in a concentration-dependent manner, an effect prevented by the KOR antagonist norbinaltorphimine (norBNI). Applied alone, norBNI increased GABAergic transmission, revealing a tonic endogenous activity at KOR. Paired-pulse analysis suggested a presynaptic KOR mechanism. Superfusion of ethanol increased IPSPs and pretreatment with KOR agonists diminished the ethanol effect. Surprisingly, the ethanol-induced augmentation of IPSPs was completely obliterated by KOR blockade. Our results reveal an important role of the dynorphin/KOR system in the regulation of inhibitory transmission and mediation of ethanol effects in the CeA.
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Affiliation(s)
- Nicholas W Gilpin
- Department of Physiology, Louisiana State University, Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70130, USA
| | - Marisa Roberto
- Committee on the Neurobiology of Addictive Disorders & Pearson Center for Alcoholism and Addiction Research, SP30 2400, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - George F Koob
- Committee on the Neurobiology of Addictive Disorders & Pearson Center for Alcoholism and Addiction Research, SP30 2400, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Paul Schweitzer
- Committee on the Neurobiology of Addictive Disorders & Pearson Center for Alcoholism and Addiction Research, SP30 2400, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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30
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Kang-Park M, Kieffer BL, Roberts AJ, Siggins GR, Moore SD. κ-Opioid receptors in the central amygdala regulate ethanol actions at presynaptic GABAergic sites. J Pharmacol Exp Ther 2013; 346:130-7. [PMID: 23587526 DOI: 10.1124/jpet.112.202903] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Human and animal studies indicate that κ-opioid receptors (KORs) are involved in ethanol drinking and dependence (Xuei et al., 2006; Walker and Koob, 2008; Walker et al., 2011). Using in vitro single-cell recording techniques in mouse brain slices, we examined the physiologic effects of KOR activation in the central amygdala (CeA) on GABAergic neurotransmission and its interaction with acute ethanol. A selective KOR agonist (U69593, 1 μM) diminished evoked GABAergic inhibitory postsynaptic currents (IPSCs) by 18% (n = 10), whereas blockade of KORs with a selective antagonist (nor-binaltorphimine, 1 μM) augmented the baseline evoked GABAergic IPSCs by 14% (P < 0.01; n = 34), suggesting that the KOR system contributes to tonic inhibition of GABAergic neurotransmission in the CeA. In addition, the enhancement by acute ethanol of GABAergic IPSC amplitudes was further augmented by pharmacologic blockade of KORs, from 14% (n = 36) to 27% (n = 26; P < 0.01), or by genetic deletion of KORs, from 14% in wild-type mice (n = 19) to 34% in KOR knockout mice (n = 13; P < 0.01). Subsequent experiments using tetrodotoxin to block activity-dependent neurotransmission suggest that KORs regulate GABA release at presynaptic sites. Our data support the idea that KORs modulate GABAergic synaptic responses and ethanol effects as one of multiple opioid system-dependent actions of ethanol in the CeA, possibly in a circuit-specific manner.
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Affiliation(s)
- Maenghee Kang-Park
- Department of Psychiatry, Duke University Medical Center, and Research Service, Veterans Administration Medical Center, Durham, North Carolina 27705, USA
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31
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Yan J, Li J, Yan J, Sun H, Wang Q, Chen K, Sun B, Wei X, Song L, Zhao X, Wei S, Han L. Activation of μ-opioid receptors in the central nucleus of the amygdala induces hypertonic sodium intake. Neuroscience 2013; 233:28-43. [DOI: 10.1016/j.neuroscience.2012.12.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/13/2012] [Accepted: 12/15/2012] [Indexed: 12/29/2022]
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32
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Poulin JF, Bérubé P, Laforest S, Drolet G. Enkephalin knockdown in the central amygdala nucleus reduces unconditioned fear and anxiety. Eur J Neurosci 2013; 37:1357-67. [DOI: 10.1111/ejn.12134] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 12/07/2012] [Accepted: 12/13/2012] [Indexed: 12/25/2022]
Affiliation(s)
- Jean-François Poulin
- Centre de recherche du CHU de Québec, Axe Neurosciences, Université Laval; Québec; QC; Canada
| | - Patrick Bérubé
- Centre de recherche du CHU de Québec, Axe Neurosciences, Université Laval; Québec; QC; Canada
| | - Sylvie Laforest
- Centre de recherche du CHU de Québec, Axe Neurosciences, Université Laval; Québec; QC; Canada
| | - Guy Drolet
- Centre de recherche du CHU de Québec, Axe Neurosciences, Université Laval; Québec; QC; Canada
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33
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Anderson EM, Neubert JK, Caudle RM. Long-term changes in reward-seeking following morphine withdrawal are associated with altered N-methyl-D-aspartate receptor 1 splice variants in the amygdala. Neuroscience 2012; 223:45-55. [PMID: 22863572 DOI: 10.1016/j.neuroscience.2012.07.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 07/11/2012] [Accepted: 07/20/2012] [Indexed: 12/23/2022]
Abstract
The NR1 subunit of the NMDA receptor can be alternatively spliced by the insertion or removal of the N1, C1, C2, or C2' regions. Morphine dependence and withdrawal were previously demonstrated to lower N1 and C2' in the accumbens and lower N1, C1, and C2' in the amygdala (AMY). Withdrawal has also been demonstrated to increase motivational and anxiety/stress behaviors in rats. We tested the hypothesis that NR1 splicing would be associated with these behaviors during an extended withdrawal period of 2 months. Motivation was measured using an operant orofacial assay at non-aversive temperatures (37°C) while anxiety and stress were measured by examining this behavior at aversive temperatures (46°C). Lower C1 and C2 expression levels were observed in the AMY in a subset of the population of withdrawn rats even after 2 months of morphine withdrawal. These subsets were associated with a hypersensitivity to adverse conditions which may reflect long-term alterations in the withdrawn population.
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Affiliation(s)
- E M Anderson
- Department of Neuroscience, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, FL 32610, USA.
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34
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Mahler SV, Berridge KC. What and when to "want"? Amygdala-based focusing of incentive salience upon sugar and sex. Psychopharmacology (Berl) 2012; 221:407-26. [PMID: 22167254 PMCID: PMC3444284 DOI: 10.1007/s00213-011-2588-6] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2011] [Accepted: 11/10/2011] [Indexed: 12/19/2022]
Abstract
RATIONALE Amygdala-related circuitry helps translate learned Pavlovian associations into appetitive and aversive motivation, especially upon subsequent encounters with cues. OBJECTIVES We asked whether μ-opioid stimulation via microinjections of the specific agonist D-Ala(2), N-MePhe(4), Gly-ol)-enkephalin (DAMGO) in central nucleus of amygdala (CeA), or the adjacent basolateral amygdala (BLA) would magnify sucrose or sex "wanting", guided by available cues. MATERIALS AND METHODS CeA or BLA DAMGO enhancement of cue-triggered "wanting" was assessed using Pavlovian to instrumental transfer (PIT). Unconditioned food "wanting" was measured via intake, and male sexual "wanting" for an estrous female was measured in a sexual approach test. Sucrose hedonic taste "liking" was measured in a taste reactivity test. RESULTS CeA (but not BLA) DAMGO increased the intensity of phasic peaks in instrumental sucrose seeking stimulated by Pavlovian cues over precue levels in PIT, while suppressing seeking at other moments. CeA DAMGO also enhanced food intake, as well as sexual approach and investigation of an estrous female by males. DAMGO "wanting" enhancements were localized to CeA, as indicated by "Fos plume"-based anatomical maps for DAMGO causation of behavioral effects. Despite increasing "wanting", CeA DAMGO decreased the hedonic impact or "liking" for sucrose in a taste reactivity paradigm. CONCLUSIONS CeA μ-opioid stimulation specifically enhances incentive salience, which is dynamically guided to food or sex by available cues.
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Affiliation(s)
- Stephen V. Mahler
- University of Michigan, Department of Psychology,Medical University of South Carolina, Department of Neurosciences
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35
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DiFeliceantonio AG, Berridge KC. Which cue to 'want'? Opioid stimulation of central amygdala makes goal-trackers show stronger goal-tracking, just as sign-trackers show stronger sign-tracking. Behav Brain Res 2012; 230:399-408. [PMID: 22391118 PMCID: PMC3322261 DOI: 10.1016/j.bbr.2012.02.032] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 02/10/2012] [Accepted: 02/18/2012] [Indexed: 10/28/2022]
Abstract
Pavlovian cues that have been paired with reward can gain incentive salience. Drug addicts find drug cues motivationally attractive and binge eaters are attracted by food cues. But the level of incentive salience elicited by a cue re-encounter still varies across time and brain states. In an animal model, cues become attractive and 'wanted' in an 'autoshaping' paradigm, where different targets of incentive salience emerge for different individuals. Some individuals (sign-trackers) find a predictive discrete cue attractive while others find a reward contiguous goal cue more attractive (location where reward arrives: goal-trackers). Here we assessed whether central amygdala mu opioid receptor stimulation enhances the phasic incentive salience of the goal-cue for goal-trackers during moments of predictive cue presence (expressed in both approach and consummatory behaviors to goal cue), just as it enhances the attractiveness of the predictive cue target for sign-trackers. Using detailed video analysis we measured the approaches, nibbles, sniffs, and bites directed at their preferred target for both sign-trackers and goal-trackers. We report that DAMGO microinjections in central amygdala made goal-trackers, like sign-trackers, show phasic increases in appetitive nibbles and sniffs directed at the goal-cue expressed selectively whenever the predictive cue was present. This indicates enhancement of incentive salience attributed by both goal trackers and sign-trackers, but attributed in different directions: each to their own target cue. For both phenotypes, amygdala opioid stimulation makes the individual's prepotent cue into a stronger motivational magnet at phasic moments triggered by a CS that predicts the reward UCS.
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36
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Beckerman MA, Glass MJ. The NMDA-NR1 receptor subunit and the mu-opioid receptor are expressed in somatodendritic compartments of central nucleus of the amygdala neurons projecting to the bed nucleus of the stria terminalis. Exp Neurol 2011; 234:112-26. [PMID: 22227057 DOI: 10.1016/j.expneurol.2011.12.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 12/02/2011] [Accepted: 12/14/2011] [Indexed: 12/26/2022]
Abstract
The pathway between the central nucleus of the amygdala (CeA) and the bed nucleus of the stria terminalis (BNST) is emerging as a critical mediator of stress-related affective processes. Evidence also indicates that exposure to drugs of abuse, like opioids, is associated with NMDA-type glutamate receptor-dependent plasticity in the CeA and BNST. However, there is little evidence that NMDA receptors are expressed in CeA neurons projecting to the BNST, or are required for opioid-induced BNST neural activation. Immunoelectron microscopy, tract tracing, and conditional gene deletion technology were used to investigate the synaptic organization of the NMDA receptor and the mu-opioid receptor (μOR) in the CeA-BNST pathway. By dual labeling electron microscopy, numerous CeA-BNST projection neurons expressed the NMDA-NR1 receptor subunit (NR1) or μOR. By triple labeling, it was also found that NR1 and μOR were co-expressed in some CeA-BNST projection neurons. Despite being colocalized in somato-dendritic compartments of CeA neurons, NR1 and μOR were rarely expressed in their axonal terminations in the BNST. Deleting the NR1 gene in CeA neurons resulted in a reduction of morphine-induced Fos protein labeling in the ventral BNST. In summary, NR1 and μOR are coexpressed in somatodendritic sites of CeA neurons, including those projecting to the BNST. In addition, expression of the NR1 gene in CeA neurons is required for morphine-induced BNST neural activation. Thus, postsynaptic NMDA receptors and μORs are positioned for the co-modulation of CeA projection neurons to the BNST, which may provide a synaptic substrate for stress-induced emotional processes critically involved in opioid addictive behaviors.
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Affiliation(s)
- Marc A Beckerman
- Department of Neurology, Weill Cornell Medical College, New York, NY 10065, USA
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37
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Abstract
The opioid system plays a crucial role in the neural modulation of anxiety. The involvement of opioid ligands and receptors in physiological and dysfunctional forms of anxiety is supported by findings from a wide range of preclinical and clinical studies, including clinical trials, experimental research, and neuroimaging, genetic, and epidemiological data. In this review we provide a summary of studies from a variety of research disciplines to elucidate the role of the opioid system in the neurobiology of anxiety. First, we report data from preclinical studies using animal models to examine the modulatory role of central opioid system on defensive responses conducive to fear and anxiety. Second, we summarize the human literature providing evidence that clinical and experimental human studies are consistent with preclinical models. The implication of these data is that activation of the opioid system leads to anxiolytic responses both in healthy subjects and in patients suffering from anxiety disorders. The role of opioids in suppressing anxiety may serve as an adaptive mechanism, collocated in the general framework of opioid neurotransmission blunting acute negative and distressing affective responses.
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Affiliation(s)
- A Colasanti
- Neuropsychopharmacology Unit, Centre for Pharmacology and Therapeutics, Division of Experimental Medicine, Imperial College London, London, UK.
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38
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Bajo M, Roberto M, Madamba SG, Siggins GR. Neuroadaptation of GABAergic transmission in the central amygdala during chronic morphine treatment. Addict Biol 2011; 16:551-64. [PMID: 21182569 PMCID: PMC3117063 DOI: 10.1111/j.1369-1600.2010.00269.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We investigated possible alterations of pharmacologically-isolated, evoked GABA(A) inhibitory postsynaptic potentials (eIPSPs) and miniature GABA(A) inhibitory postsynaptic currents (mIPSCs) in the rat central amygdala (CeA) elicited by acute application of µ-opioid receptor (MOR) agonists (DAMGO and morphine; 1 µM) and by chronic morphine treatment with morphine pellets. The acute activation of MORs decreased the amplitudes of eIPSPs, increased paired-pulse facilitation (PPF) of eIPSPs and decreased the frequency (but not the amplitude) of mIPSCs in a majority of CeA neurons, suggesting that acute MOR-dependent modulation of this GABAergic transmission is mediated predominantly via presynaptic inhibition of GABA release. We observed no significant changes in the membrane properties, eIPSPs, PPF or mIPSCs of CeA neurons during chronic morphine treatment compared to CeA of naïve or sham rats. Superfusion of the MOR antagonist CTOP (1 µM) increased the mean amplitude of eIPSPs in a majority of CeA neurons to the same degree in both naïve/sham and morphine-treated rats, suggesting a tonic activation of MORs in both conditions. Superfusion of DAMGO decreased eIPSP amplitudes and the frequency of mIPSCs equally in both naïve/sham and morphine-treated rats but decreased the amplitude of mIPSCs only in morphine treated rats, an apparent postsynaptic action. Our combined findings suggest the development of tolerance of the CeA GABAergic system to inhibitory effects of acute activation of MORs on presynaptic GABA release and possible alteration of MOR-dependent postsynaptic mechanisms that may represent important neuroadaptations of the GABAergic and MOR systems during chronic morphine treatment.
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MESH Headings
- Amygdala/drug effects
- Amygdala/physiology
- Analgesics, Opioid/pharmacology
- Animals
- Drug Tolerance
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Inhibitory Postsynaptic Potentials/drug effects
- Inhibitory Postsynaptic Potentials/physiology
- Male
- Miniature Postsynaptic Potentials/drug effects
- Miniature Postsynaptic Potentials/physiology
- Morphine/pharmacology
- Narcotics/pharmacology
- Neurons/drug effects
- Neurons/physiology
- Patch-Clamp Techniques
- Rats
- Rats, Sprague-Dawley
- Receptors, GABA-A/drug effects
- Receptors, GABA-A/physiology
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/physiology
- Somatostatin/analogs & derivatives
- Somatostatin/pharmacology
- Synaptic Transmission/drug effects
- Synaptic Transmission/physiology
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Affiliation(s)
- Michal Bajo
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, California, USA
| | - Marisa Roberto
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California, USA
| | - Samuel G. Madamba
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, California, USA
| | - George Robert Siggins
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, California, USA
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39
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Knoll AT, Muschamp JW, Sillivan SE, Ferguson D, Dietz DM, Meloni EG, Carroll FI, Nestler EJ, Konradi C, Carlezon WA. Kappa opioid receptor signaling in the basolateral amygdala regulates conditioned fear and anxiety in rats. Biol Psychiatry 2011; 70:425-33. [PMID: 21531393 PMCID: PMC3150294 DOI: 10.1016/j.biopsych.2011.03.017] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 03/07/2011] [Accepted: 03/10/2011] [Indexed: 10/18/2022]
Abstract
BACKGROUND The kappa opioid receptor (KOR) system contributes to the prodepressive and aversive consequences of stress and is implicated in the facilitation of conditioned fear and anxiety in rodents. Here, we sought to identify neural circuits that mediate KOR system effects on fear and anxiety in rats. METHODS We assessed whether fear conditioning induces plasticity in KOR or dynorphin (the endogenous KOR ligand) messenger RNA (mRNA) expression in the basolateral (BLA) and central (CeA) nuclei of the amygdala, hippocampus, or striatum. We then assessed whether microinfusions of the KOR antagonist JDTic (0-10 μg/side) into the BLA or CeA affect the expression of conditioned fear or anxiety. Finally, we examined whether fear extinction induces plasticity in KOR mRNA expression that relates to the quality of fear extinction. RESULTS Fear conditioning upregulated KOR mRNA in the BLA by 65% and downregulated it in the striatum by 22%, without affecting KOR levels in the CeA or hippocampus, or dynorphin levels in any region. KOR antagonism in either the BLA or CeA decreased conditioned fear in the fear-potentiated startle paradigm, whereas KOR antagonism in the BLA, but not the CeA, produced anxiolytic-like effects in the elevated plus maze. Effective fear extinction was associated with a 67% reduction in KOR mRNA in the BLA. CONCLUSIONS These findings suggest that fear conditioning and extinction dynamically regulate KOR expression in the BLA and provide evidence that the BLA and CeA are important neural substrates mediating the anxiolytic-like effects of KOR antagonists in models of fear and anxiety.
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MESH Headings
- Amygdala/drug effects
- Amygdala/metabolism
- Animals
- Anxiety/metabolism
- Conditioning, Psychological/drug effects
- Conditioning, Psychological/physiology
- Corpus Striatum/drug effects
- Corpus Striatum/metabolism
- Disease Models, Animal
- Dynorphins/physiology
- Extinction, Psychological/physiology
- Fear/drug effects
- Fear/physiology
- Gene Expression Regulation/physiology
- Hippocampus/drug effects
- Hippocampus/metabolism
- Male
- Maze Learning/drug effects
- Maze Learning/physiology
- Microinjections
- Piperidines/administration & dosage
- Piperidines/pharmacology
- Rats
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/biosynthesis
- Receptors, Opioid, kappa/physiology
- Reflex, Startle/drug effects
- Reflex, Startle/physiology
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Tetrahydroisoquinolines/administration & dosage
- Tetrahydroisoquinolines/pharmacology
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Affiliation(s)
- Allison T. Knoll
- Behavioral Genetics Laboratory, Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478 (ATK, JWM, EGM, WAC)
| | - John W. Muschamp
- Behavioral Genetics Laboratory, Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478 (ATK, JWM, EGM, WAC)
| | | | - Deveroux Ferguson
- Fishberg Department of Neuroscience, Mount Sinai School of Medicine, New York, NY, 10029 (DF, DMD, EJN)
| | - David M. Dietz
- Fishberg Department of Neuroscience, Mount Sinai School of Medicine, New York, NY, 10029 (DF, DMD, EJN)
| | - Edward G. Meloni
- Behavioral Genetics Laboratory, Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478 (ATK, JWM, EGM, WAC)
| | - F. Ivy Carroll
- Research Triangle Institute, Organic and Medicinal Chemistry, Research Triangle Park, NC 27709 (FIC)
| | - Eric J. Nestler
- Fishberg Department of Neuroscience, Mount Sinai School of Medicine, New York, NY, 10029 (DF, DMD, EJN)
| | - Christine Konradi
- Department of Pharmacology and Psychiatry, Vanderbilt University, Nashville, TN 37232 (CK)
| | - William A. Carlezon
- Behavioral Genetics Laboratory, Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478 (ATK, JWM, EGM, WAC)
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40
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Scavone JL, Asan E, Van Bockstaele EJ. Unraveling glutamate-opioid receptor interactions using high-resolution electron microscopy: implications for addiction-related processes. Exp Neurol 2011; 229:207-13. [PMID: 21459090 DOI: 10.1016/j.expneurol.2011.03.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 03/11/2011] [Accepted: 03/21/2011] [Indexed: 11/24/2022]
Abstract
Adaptive responses in glutamate and opioid receptor systems in limbic circuits are emerging as a critical component of the neural plasticity induced by chronic use of abused substances. The present commentary reviews findings from neuroanatomical studies, with superior spatial resolution, that support a cellular basis for prominent interactions of glutamate and opioid receptor systems in preclinical models of drug addiction. The review begins by highlighting the advantages of high-resolution electron microscopic immunohistochemistry for unraveling receptor interactions at the synapse. With an emphasis on a recent publication describing the anatomical relationship between the μ-opioid receptor (MOR) and the AMPA-GluR2 subunit (Beckerman, M. A., and Glass, M. J., 2011. Ultrastructural relationship between the AMPA-GluR2 receptor subunit and the mu-opioid receptor in the mouse central nucleus of the amygdala. Exp Neurol), we review the anatomical evidence for opioid-induced neural plasticity of glutamate receptors in selected brain circuits that are key integrative substrates in the brain's motivational system. The findings stress the importance of glutamate-opioid interactions as important neural mediators of adaptations to chronic use of abused drugs, particularly within the amygdaloid complex.
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Affiliation(s)
- Jillian L Scavone
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
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41
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Ardjmand A, Rezayof A, Zarrindast MR. Involvement of central amygdala NMDA receptor mechanism in morphine state-dependent memory retrieval. Neurosci Res 2011; 69:25-31. [DOI: 10.1016/j.neures.2010.09.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 08/25/2010] [Accepted: 09/14/2010] [Indexed: 12/11/2022]
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42
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Chieng B, Christie MJ. Somatostatin and nociceptin inhibit neurons in the central nucleus of amygdala that project to the periaqueductal grey. Neuropharmacology 2010; 59:425-30. [PMID: 20541564 DOI: 10.1016/j.neuropharm.2010.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 06/01/2010] [Accepted: 06/02/2010] [Indexed: 01/08/2023]
Abstract
The central nucleus of amygdala (CeA) plays an important role in modulation of the descending antinociceptive pathways. Using whole-cell patch clamp recordings from brain slices, we found that CeA neurons responded to the endogenous ligands somatostatin (SST) and nociceptin/orphanin FQ (OFQ) via an increased K-conductance. Co-application with selective antagonists suggested that SST and OFQ act on SSTR2 and ORL1 receptors, respectively. Taking account of anatomical localisation of recorded neurons, the present study showed that many responsive neurons were located within the medial subdivision of CeA and all CeA projection neurons to the midbrain periaqueductal grey invariably responded to these peptides. Randomly selected agonist-responsive neurons in CeA predominantly classified physiologically as low-threshold spiking neurons. The similarity of SST, OFQ and, as previously reported, opioid responsiveness in a sub-population of CeA neurons suggests converging roles of these peptides to inhibit the activity of projections from CeA to vlPAG, and potentially similar antinociceptive actions in this pathway.
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Affiliation(s)
- Billy Chieng
- Brain & Mind Research Institute, University of Sydney, 100 Mallett St, Camperdown, NSW 2050, Australia.
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The endocannabinoid system tonically regulates inhibitory transmission and depresses the effect of ethanol in central amygdala. Neuropsychopharmacology 2010; 35:1962-72. [PMID: 20463657 PMCID: PMC2904853 DOI: 10.1038/npp.2010.70] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The central amygdala (CeA) has a major role in alcohol dependence and reinforcement, and behavioral and neurochemical evidence suggests a role for the endocannabinoid (eCB) system in ethanol binging and dependence. We used a slice preparation to investigate the physiological role of cannabinoids and their interaction with ethanol on inhibitory synaptic transmission in CeA. Superfusion of the cannabinoid receptor (CB1) agonist WIN55212-2 (WIN2) onto CeA neurons decreased evoked GABA(A) receptor-mediated inhibitory postsynaptic potentials (IPSPs) in a concentration-dependent manner, an effect prevented by the CB1 antagonists Rimonabant (SR141716, SR1) and AM251. SR1 or AM251 applied alone augmented IPSPs, revealing a tonic eCB activity that decreased inhibitory transmission in CeA. Paired-pulse analysis suggested a presynaptic CB1 mechanism. Intracellular BAPTA abolished the ability of AM251 to augment IPSPs, demonstrating the eCB-driven nature and postsynaptic origin of the tonic CB1-dependent control of GABA release. Superfusion of ethanol increased IPSPs and addition of WIN2 reversed the ethanol effect. Similarly, previous superfusion of WIN2 prevented subsequent ethanol effects on GABAergic transmission. The ethanol-induced augmentation of IPSPs was additive to CB1 blockade, ruling out a participation of CB1 in the action of acute ethanol. Our study points to an important role of CB1 in CeA in which the eCBs tonically regulate neuronal activity, and suggests a potent mechanism for modulating CeA tone during challenge with ethanol.
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Rassouli Y, Rezayof A, Zarrindast MR. Role of the central amygdala GABA-A receptors in morphine state-dependent memory. Life Sci 2010; 86:887-93. [DOI: 10.1016/j.lfs.2010.04.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 04/07/2010] [Accepted: 04/12/2010] [Indexed: 10/19/2022]
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Glass MJ. The role of functional postsynaptic NMDA receptors in the central nucleus of the amygdala in opioid dependence. VITAMINS AND HORMONES 2010; 82:145-66. [PMID: 20472137 DOI: 10.1016/s0083-6729(10)82008-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Activation of ionotropic N-methyl-D-aspartate (NMDA)-type glutamate receptors in limbic system nuclei, such as the central nucleus of the amygdala (CeA), plays an essential role in autonomic, behavioral, and affective processes that are profoundly impacted by exposure to opioids. However, the heterogeneous ultrastructural distribution of the NMDA receptor, its complex pharmacology, and the paucity of genetic models have hampered the development of linkages between functional amygdala NMDA receptors and opioid dependence. To overcome these shortcomings, high-resolution imaging and molecular pharmacology were used to (1) Identify the ultrastructural localization of the essential NMDA-NR1 receptor (NR1) subunit and its relationship to the mu-opioid receptor (microOR), the major cellular target of abused opioids like morphine, in the CeA and (2) Determine the effect of CeA NR1 deletion on the physical, and particularly, psychological aspects of opioid dependence. Combined immunogold and immuoperoxidase electron microscopic analysis showed that NR1 was prominently expressed in postsynaptic (i.e., somata, dendrites) locations of CeA neurons, where they were also frequently colocalized with the microOR. A spatial-temporal deletion of NR1 in postsynaptic sites of CeA neurons was produced by local microinjection of a neurotropic recombinant adeno-associated virus (rAAV), expressing the green fluorescent protein (GFP) reporter and Cre recombinase (rAAV-GFP-Cre), in adult "floxed" NR1 (fNR1) mice. Mice with deletion of NR1 in the CeA showed no obvious impairments in sensory, motor, or nociceptive function. In addition, when administered chronic morphine, these mice also displayed an acute physical withdrawal syndrome precipitated by naloxone. However, opioid-dependent CeA NR1 knockout mice failed to exhibit a conditioned place aversion induced by naloxone-precipitated withdrawal. These results indicate that postsynaptic NMDA receptor activity in central amygdala neurons is required for the expression of a learned affective behavior associated with opioid withdrawal. The neurogenetic dissociation of physical and psychological properties of opioid dependence demonstrates the value of combined ultrastructural analysis and molecular pharmacology in clarifying the neurobiological mechanisms subserving opioid-mediated plasticity.
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Affiliation(s)
- Michael J Glass
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, USA
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Lu HC, Hsieh JC, Lu CL, Niddam DM, Wu YT, Yeh TC, Cheng CM, Chang FY, Lee SD. Neuronal correlates in the modulation of placebo analgesia in experimentally-induced esophageal pain: a 3T-fMRI study. Pain 2009; 148:75-83. [PMID: 19962240 DOI: 10.1016/j.pain.2009.10.012] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 09/05/2009] [Accepted: 10/15/2009] [Indexed: 10/20/2022]
Abstract
Visceral pain/discomfort is the cardinal complaints and treatment targets for functional gastrointestinal disorders (FGID). However, effective treatment for such pain is limited and often associated with high placebo effects. The mechanisms of placebo effects in visceral pain are unclear. We used functional neuroimaging to study the central representations of the placebo effect and its anticipation during esophageal pain in healthy adults. Fourteen subjects were enrolled. Pain extent, psychophysical inventories [Pain Catastrophizing Scale (PAS), visual analogue scale (VAS) and short-form McGill questionnaire], and brain activity upon placebo intervention and upon anticipation were assessed in response to esophageal balloon distension. Large reductions of pain extent, VAS rating, short-form McGill questionnaire scores, and brain activity in the visceral pain matrix [thalamus, somatosensory cortices, insula, prefrontal cortex (PFC), anterior cingulate cortex] were observed upon placebo treatment. The aforementioned brain areas and the bilateral amygdala were significantly correlated with decreased pain extent and VAS in response to placebo. The ventral lateral PFC (VLPFC) was associated with increased activity during anticipation of visceral pain. PAS cannot predict the placebo effect in visceral pain. In conclusion, pronounced placebo analgesia was coupled with prominent changes of brain activity in visceral pain matrix, which are thus likely involved in high placebo efficacy during the treatment of visceral pain in FGID. VLPFC activation during the anticipation of placebo analgesia suggests top-down control in the modulation of pain experience.
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Affiliation(s)
- Hsueh-Chieh Lu
- Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan Department of Internal Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan Department of Biomedical Imaging and Radiological Sciences, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei, Taiwan Division of Gastroenterology, Taipei Veterans General Hospital, Taipei, Taiwan Integrated Brain Research Laboratory, Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan
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Ultrastructural relationship between N-methyl-D-aspartate-NR1 receptor subunit and mu-opioid receptor in the mouse central nucleus of the amygdala. Neuroscience 2009; 163:857-67. [PMID: 19607886 DOI: 10.1016/j.neuroscience.2009.07.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 07/09/2009] [Accepted: 07/10/2009] [Indexed: 12/23/2022]
Abstract
The central nucleus of the amygdala (CeA) is an important neuroanatomical substrate of emotional processes that are critically involved in addictive behaviors. Glutamate and opioid systems in the CeA play significant roles in neural plasticity and addictive processes, however the cellular sites of interaction between agonists of N-methyl-d-aspartate (NMDA) and mu-opioid receptors (muOR) in the CeA are unknown. Dual labeling immunocytochemistry was used to determine the ultrastructural relationship between the essential NMDA-NR1 receptor subunit and muOR in the CeA. It was found that over 80% of NR1-labeled profiles were dendrites while less than 10% were axons. In the case of muOR-labeled profiles, approximately 60% were dendritic, and over 35% were axons. Despite their somewhat distinctive patterns of cellular location, numerous dual-labeled profiles were observed. Approximately 80% of these were dendritic, and less than 10% were axonal. Moreover, many dual-labeled dendritic profiles were contacted by axon terminals receiving asymmetric-type synapses indicative of excitatory signaling. These results indicate that NMDA and muORs are strategically localized in dendrites, including those receiving excitatory synapses, of central amygdala neurons. Thus, postsynaptic co-modulation of central amygdala neurons may be a key cellular substrate mediating glutamate and opioid interaction on neural signaling and plasticity associated with normal and pathological emotional processes associated with addictive behaviors.
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Bie B, Zhu W, Pan ZZ. Ethanol-induced delta-opioid receptor modulation of glutamate synaptic transmission and conditioned place preference in central amygdala. Neuroscience 2009; 160:348-58. [PMID: 19258026 PMCID: PMC2669697 DOI: 10.1016/j.neuroscience.2009.02.049] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 02/18/2009] [Accepted: 02/22/2009] [Indexed: 12/15/2022]
Abstract
Alcoholism involves compulsive behaviors of alcohol drinking, which is thought to be related at least initially to the rewarding effect of alcohol. It has been shown that mu-opioid receptors play an essential role in drug reward and dependence for many drugs of abuse including alcohol, but the function of delta-opioid receptors (DOR) in drug reward remains largely unknown at present. Previous animal studies using systemic approaches with DOR antagonists or DOR knockout animals have yielded inconsistent results, showing a decrease, an increase or no change in alcohol consumption and behaviors of alcohol reward after DOR inhibition or deletion. In the present study, we used ethanol-conditioned rats to investigate adaptive DOR function in neurons of the central nucleus of the amygdala (CeA), a key brain site for alcohol reward and addiction. We found that functional DOR was absent in glutamate synapses of CeA neurons from control rats, but it emerged and inhibited glutamate synaptic currents in CeA neurons from rats displaying ethanol-induced behavior of conditioned place preference (CPP). Analysis of paired-pulse ratios and miniature glutamate synaptic currents revealed that the recruited DOR was present on glutamatergic presynaptic terminals. Similar induction of functional DOR was also found on GABA synapses. Furthermore, microinjection of a DOR antagonist into the CeA reversed ethanol-induced CPP behavior in rats in vivo. These results suggest that repeated alcohol exposure recruits new functional DOR on CeA glutamate and GABA synapses, which may be involved in the expression or maintenance of ethanol-induced CPP behavior.
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Affiliation(s)
- Bihua Bie
- Department of Anesthesiology and Pain Medicine, The University of Texas-MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030
| | - Wei Zhu
- Department of Anesthesiology and Pain Medicine, The University of Texas-MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030
| | - Zhizhong Z. Pan
- Department of Anesthesiology and Pain Medicine, The University of Texas-MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030
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Rezayof A, Khajehpour L, Zarrindast M. The amygdala modulates morphine-induced state-dependent memory retrieval via muscarinic acetylcholine receptors. Neuroscience 2009; 160:255-63. [DOI: 10.1016/j.neuroscience.2009.02.069] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 02/26/2009] [Accepted: 02/28/2009] [Indexed: 10/21/2022]
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GABA and opioid mechanisms of the central amygdala underlie the withdrawal-potentiated startle from acute morphine. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:334-44. [PMID: 19150477 DOI: 10.1016/j.pnpbp.2008.12.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 11/25/2008] [Accepted: 12/17/2008] [Indexed: 11/23/2022]
Abstract
Anxiety is an affective symptom common to withdrawal from acute or chronic opiate treatment. Although the potentiation of the acoustic startle reflex has been proposed as an index of increased anxiety, there are variable effects of the opiate withdrawal on the startle reflex in chronic dependence models. On the other hand, withdrawal from acute morphine treatment consistently potentiates the acoustic startle reflex, a response that seems to be mediated by the central nucleus of the amygdala (CeA). However, the underlying neurochemical mechanisms have not been elucidated yet. In the present study, we firstly made a comparison between the effects of the withdrawal from both acute and chronic treatments with morphine on the motor activity and the anxiety-like behavior of rats tested in two experimental models, the acoustic startle reflex and the open-field tests. Our second objective was to investigate the role of GABAergic and opioid mechanisms of the CeA in the modulation of the withdrawal-potentiated startle as a measure of anxiety induced by morphine withdrawal. For the production of chronic dependence, rats received morphine injections (10 mg/kg; s.c.) twice daily during 10 days. Forty-eight hours after the interruption of this treatment, independent groups were probed in the startle reflex and open-field tests. For the acute dependence model, groups of rats were tested in the open field and startle tests under control conditions and under withdrawal from a single injection of morphine (10 mg/kg; s.c.) precipitated by naltrexone injections (0.1 mg/kg; s.c.). The results obtained showed that withdrawal from chronic and acute morphine treatments produced anxiety-like behavior in the open field test, although the anxiogenic-like effects could not be dissociated from the motor effects in the acute dependence model. On the other hand, only the withdrawal from acute morphine treatment significantly potentiated the startle response. Next, we examined the effects of intra-CeA microinjections of muscimol-a GABA(A) receptors agonist-and DAMGO-a mu-opioid receptors agonist-on the potentiated startle induced by acute morphine withdrawal. The results obtained showed that intra-CeA injections of muscimol (1 nmol) and DAMGO (0.5 and 1 nmol) significantly inhibited this response. These findings suggest that the acute dependence model is more suitable to study the aversive effects of morphine withdrawal on the acoustic startle response than the chronic opiate dependence model. Besides, mechanisms mediated by mu- and GABA(A)-receptors in the CeA appear to exert an inhibitory influence on the anxiety-like behavior induced by withdrawal from acute morphine treatment.
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