1
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Kirouac GJ, Li S, Li S. Convergence of monosynaptic inputs from neurons in the brainstem and forebrain on parabrachial neurons that project to the paraventricular nucleus of the thalamus. Brain Struct Funct 2022; 227:2409-2437. [PMID: 35838792 PMCID: PMC9418111 DOI: 10.1007/s00429-022-02534-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 06/30/2022] [Indexed: 11/28/2022]
Abstract
The paraventricular nucleus of the thalamus (PVT) projects to areas of the forebrain involved in regulating behavior. Homeostatic challenges and salient cues activate the PVT and evidence shows that the PVT regulates appetitive and aversive responses. The brainstem is a source of afferents to the PVT and the present study was done to determine if the lateral parabrachial nucleus (LPB) is a relay for inputs to the PVT. Retrograde tracing experiments with cholera toxin B (CTB) demonstrate that the LPB contains more PVT projecting neurons than other regions of the brainstem including the catecholamine cell groups. The hypothesis that the LPB is a relay for signals to the PVT was assessed using an intersectional monosynaptic rabies tracing approach. Sources of inputs to LPB included the reticular formation; periaqueductal gray (PAG); nucleus cuneiformis; and superior and inferior colliculi. Distinctive clusters of input cells to LPB-PVT projecting neurons were also found in the dorsolateral bed nucleus of the stria terminalis (BSTDL) and the lateral central nucleus of the amygdala (CeL). Anterograde viral tracing demonstrates that LPB-PVT neurons densely innervate all regions of the PVT in addition to providing collateral innervation to the preoptic area, lateral hypothalamus, zona incerta and PAG but not the BSTDL and CeL. The paper discusses the anatomical evidence that suggests that the PVT is part of a network of interconnected neurons involved in arousal, homeostasis, and the regulation of behavioral states with forebrain regions potentially providing descending modulation or gating of signals relayed from the LPB to the PVT.
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Affiliation(s)
- Gilbert J Kirouac
- Department of Oral Biology, Dr. Gerald Niznick College of Dentistry, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Avenue, Winnipeg, MB, R3E 0W2, Canada. .,Departments of Psychiatry and Human Anatomy and Cell Sciences, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, R3E 0W2, Canada.
| | - Sa Li
- Department of Oral Biology, Dr. Gerald Niznick College of Dentistry, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Avenue, Winnipeg, MB, R3E 0W2, Canada
| | - Shuanghong Li
- Department of Oral Biology, Dr. Gerald Niznick College of Dentistry, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Avenue, Winnipeg, MB, R3E 0W2, Canada
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2
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Presto P, Neugebauer V. Sex Differences in CGRP Regulation and Function in the Amygdala in a Rat Model of Neuropathic Pain. Front Mol Neurosci 2022; 15:928587. [PMID: 35726298 PMCID: PMC9206543 DOI: 10.3389/fnmol.2022.928587] [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: 04/25/2022] [Accepted: 05/12/2022] [Indexed: 12/02/2022] Open
Abstract
The amygdala has emerged as a key player in the emotional response to pain and pain modulation. The lateral and capsular regions of the central nucleus of the amygdala (CeA) represent the “nociceptive amygdala” due to their high content of neurons that process pain-related information. These CeA divisions are the targets of the spino-parabrachio-amygdaloid pain pathway, which is the predominant source of calcitonin gene-related peptide (CGRP) within the amygdala. Changes in lateral and capsular CeA neurons have previously been observed in pain models, and synaptic plasticity in these areas has been linked to pain-related behavior. CGRP has been demonstrated to play an important role in peripheral and spinal mechanisms, and in pain-related amygdala plasticity in male rats in an acute arthritis pain model. However, the role of CGRP in chronic neuropathic pain-related amygdala function and behaviors remains to be determined for both male and female rats. Here we tested the hypothesis that the CGRP1 receptor is involved in neuropathic pain-related amygdala activity, and that blockade of this receptor can inhibit neuropathic pain behaviors in both sexes. CGRP mRNA expression levels in the CeA of male rats were upregulated at the acute stage of the spinal nerve ligation (SNL) model of neuropathic pain, whereas female rats had significantly higher CGRP and CGRP receptor component expression at the chronic stage. A CGRP1 receptor antagonist (CGRP 8-37) administered into the CeA in chronic neuropathic rats reduced mechanical hypersensitivity (von Frey and paw compression tests) in both sexes but showed female-predominant effects on emotional-affective responses (ultrasonic vocalizations) and anxiety-like behaviors (open field test). CGRP 8-37 inhibited the activity of CeA output neurons assessed with calcium imaging in brain slices from chronic neuropathic pain rats. Together, these findings may suggest that CGRP1 receptors in the CeA are involved in neuropathic pain-related amygdala activity and contribute to sensory aspects in both sexes but to emotional-affective pain responses predominantly in females. The sexually dimorphic function of CGRP in the amygdala would make CGRP1 receptors a potential therapeutic target for neuropathic pain relief, particularly in females in chronic pain conditions.
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Affiliation(s)
- Peyton Presto
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Volker Neugebauer
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, United States
- Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, United States
- Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX, United States
- *Correspondence: Volker Neugebauer
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3
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Li JN, Chen K, Sheets PL. Topographic organization underlies intrinsic and morphological heterogeneity of central amygdala neurons expressing corticotropin-releasing hormone. J Comp Neurol 2022; 530:2286-2303. [PMID: 35579999 PMCID: PMC9283236 DOI: 10.1002/cne.25332] [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: 06/30/2021] [Revised: 04/08/2022] [Accepted: 04/13/2022] [Indexed: 11/30/2022]
Abstract
The central nucleus of the amygdala (CeA) network consists of a heterogeneous population of inhibitory GABAergic neurons distributed across distinct subregions. While the specific roles for molecularly defined CeA neurons have been extensively studied, our understanding of functional heterogeneity within classes of molecularly distinct CeA neurons remains incomplete. In addition, manipulation of genetically defined CeA neurons has produced inconsistent behavioral results potentially due to broad targeting across CeA subregions. Therefore, elucidating heterogeneity within molecularly defined neurons in subdivisions of the CeA is pivotal for gaining a complete understanding of how CeA circuits function. Here, we used a multifaceted approach involving transgenic reporter mice, brain slice electrophysiology, and neuronal morphology to dissect the heterogeneity of corticotropin‐releasing hormone (CRH) neurons in topographically distinct subregions of the CeA. Our results revealed that intrinsic and morphological properties of CRH‐expressing (CRH+) neurons in the lateral (CeL) and medial (CeM) subdivisions of the CeA were significantly different. We found that CeL‐CRH+ neurons are relatively homogeneous in morphology and firing profile. Conversely, CeM‐CRH+ neurons displayed heterogeneous electrophysiological and morphological phenotypes. Overall, these results show phenotypic differences between CRH+ neurons in CeL and CeM.
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Affiliation(s)
- Jun-Nan Li
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Department of Anesthesiology, Washington University Pain Center, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA.,Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Kevin Chen
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Zionsville Community High School, Zionsville, Indiana, USA
| | - Patrick L Sheets
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA
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4
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Shah T, Dunning JL, Contet C. At the heart of the interoception network: Influence of the parasubthalamic nucleus on autonomic functions and motivated behaviors. Neuropharmacology 2022; 204:108906. [PMID: 34856204 PMCID: PMC8688299 DOI: 10.1016/j.neuropharm.2021.108906] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 02/05/2023]
Abstract
The parasubthalamic nucleus (PSTN), a small nucleus located on the lateral edge of the posterior hypothalamus, has emerged in recent years as a highly interconnected node within the network of brain regions sensing and regulating autonomic function and homeostatic needs. Furthermore, the strong integration of the PSTN with extended amygdala circuits makes it ideally positioned to serve as an interface between interoception and emotions. While PSTN neurons are mostly glutamatergic, some of them also express neuropeptides that have been associated with stress-related affective and motivational dysfunction, including substance P, corticotropin-releasing factor, and pituitary adenylate-cyclase activating polypeptide. PSTN neurons respond to food ingestion and anorectic signals, as well as to arousing and distressing stimuli. Functional manipulation of defined pathways demonstrated that the PSTN serves as a central hub in multiple physiologically relevant networks and is notably implicated in appetite suppression, conditioned taste aversion, place avoidance, impulsive action, and fear-induced thermoregulation. We also discuss the putative role of the PSTN in interoceptive dysfunction and negative urgency. This review aims to synthesize the burgeoning preclinical literature dedicated to the PSTN and to stimulate interest in further investigating its influence on physiology and behavior.
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Affiliation(s)
- Tanvi Shah
- The Scripps Research Institute, Department of Molecular Medicine, La Jolla, CA, USA
| | - Jeffery L Dunning
- The Scripps Research Institute, Department of Molecular Medicine, La Jolla, CA, USA
| | - Candice Contet
- The Scripps Research Institute, Department of Molecular Medicine, La Jolla, CA, USA.
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5
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Tokunaga R, Takahashi Y, Touj S, Hotta H, Leblond H, Kato F, Piché M. Attenuation of widespread hypersensitivity to noxious mechanical stimuli by inhibition of GABAergic neurons of the right amygdala in a rat model of chronic back pain. Eur J Pain 2022; 26:911-928. [DOI: 10.1002/ejp.1921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 02/06/2022] [Indexed: 11/06/2022]
Affiliation(s)
- R. Tokunaga
- Department of Anatomy Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada G9A 5H7
- CogNAC Research Group Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada G9A 5H7
| | - Y. Takahashi
- Department of Neuroscience Jikei University School of Medicine Tokyo Japan
| | - S. Touj
- Department of Anatomy Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada G9A 5H7
- CogNAC Research Group Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada G9A 5H7
| | - H. Hotta
- Department of Autonomic Neuroscience Tokyo Metropolitan Institute of Gerontology Tokyo Japan
| | - H. Leblond
- Department of Anatomy Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada G9A 5H7
- CogNAC Research Group Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada G9A 5H7
| | - F. Kato
- Department of Neuroscience Jikei University School of Medicine Tokyo Japan
| | - M. Piché
- Department of Anatomy Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada G9A 5H7
- CogNAC Research Group Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada G9A 5H7
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6
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Jaramillo AA, Brown JA, Winder DG. Danger and distress: Parabrachial-extended amygdala circuits. Neuropharmacology 2021; 198:108757. [PMID: 34461068 DOI: 10.1016/j.neuropharm.2021.108757] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 08/04/2021] [Accepted: 08/18/2021] [Indexed: 12/21/2022]
Abstract
Our understanding of the role of the parabrachial nucleus (PBN) has evolved as technology has advanced, in part due to cell-specific studies and complex behavioral assays. This is reflected in the heterogeneous neuronal populations within the PBN to the extended amygdala (EA) circuits which encompass the bed nucleus of the stria terminalis (BNST) and central amygdala (CeA) circuitry, as they differentially modulate aspects of behavior in response to diverse threat-like contexts necessary for survival. Here we review how the PBN→CeA and PBN→BNST pathways differentially modulate fear-like behavior, innate and conditioned, through unique changes in neurotransmission in response to stress-inducing contexts. Furthermore, we hypothesize how in specific instances the PBN→CeA and PBN→BNST circuits are redundant and in part intertwined with their respective reciprocal projections. By deconstructing the interoceptive and exteroceptive components of affect- and stress related behavioral paradigms, evidence suggests that the PBN→CeA circuit modulates innate response to physical stimuli and fear conditioning. Conversely, the PBN→BNST circuit modulates distress-like stress in unpredictable contexts. Thereby, the PBN provides a pathway for alarming interoceptive and exteroceptive stimuli to be processed and relayed to the EA to induce stress-relevant affect. Additionally, we provide a framework for future studies to detail the cell-type specific intricacies of PBN→EA circuits in mediating behavioral responses to threats, and the relevance of the PBN in drug-use as it relates to threat and negative reinforcement. This article is part of the special Issue on 'Neurocircuitry Modulating Drug and Alcohol Abuse'.
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Affiliation(s)
- A A Jaramillo
- Vanderbilt University School of Medicine, Nashville, TN, USA; Dept. Mol. Phys. & Biophysics, USA; Vanderbilt Brain Institute, USA; Vanderbilt Center for Addiction Research, USA
| | - J A Brown
- Vanderbilt University School of Medicine, Nashville, TN, USA; Dept. Mol. Phys. & Biophysics, USA; Vanderbilt Brain Institute, USA; Vanderbilt Center for Addiction Research, USA; Department of Pharmacology, USA
| | - D G Winder
- Vanderbilt University School of Medicine, Nashville, TN, USA; Dept. Mol. Phys. & Biophysics, USA; Vanderbilt Brain Institute, USA; Vanderbilt Center for Addiction Research, USA; Department of Pharmacology, USA; Vanderbilt Kennedy Center, USA; Department of Psychiatry & Behavioral Sciences, USA.
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7
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Ito M, Nagase M, Tohyama S, Mikami K, Kato F, Watabe AM. The parabrachial-to-amygdala pathway provides aversive information to induce avoidance behavior in mice. Mol Brain 2021; 14:94. [PMID: 34167570 PMCID: PMC8223383 DOI: 10.1186/s13041-021-00807-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/10/2021] [Indexed: 11/10/2022] Open
Abstract
The neuronal circuitry for pain signals has been intensively studied for decades. The external lateral parabrachial nucleus (PB) was shown to play a crucial role in nociceptive information processing. Previous work, including ours, has demonstrated that stimulating the neuronal pathway from the PB to the central region of the amygdala (CeA) can substitute for an actual pain signal to drive an associative form of threat/fear memory formation. However, it is still unknown whether activation of the PB-CeA pathway can directly drive avoidance behavior, escape behavior, or only acts as strategic freezing behavior for later memory retrieval. To directly address this issue, we have developed a real-time Y-maze conditioning behavioral paradigm to examine avoidance behavior induced by optogenetic stimulation of the PB-CeA pathway. In this current study, we have demonstrated that the PB-CeA pathway carries aversive information that can directly trigger avoidance behavior and thereby serve as an alarm signal to induce adaptive behaviors for later decision-making.
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Affiliation(s)
- Mariko Ito
- Department of Neuroscience, The Jikei University School of Medicine, Tokyo, Japan
- Institute of Clinical Medicine and Research, Research Center for Medical Sciences, The Jikei University School of Medicine, 163-1 Kashiwa-shita, Kashiwa, Chiba, 277-8567, Japan
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Masashi Nagase
- Institute of Clinical Medicine and Research, Research Center for Medical Sciences, The Jikei University School of Medicine, 163-1 Kashiwa-shita, Kashiwa, Chiba, 277-8567, Japan
| | - Suguru Tohyama
- Institute of Clinical Medicine and Research, Research Center for Medical Sciences, The Jikei University School of Medicine, 163-1 Kashiwa-shita, Kashiwa, Chiba, 277-8567, Japan
| | - Kaori Mikami
- Institute of Clinical Medicine and Research, Research Center for Medical Sciences, The Jikei University School of Medicine, 163-1 Kashiwa-shita, Kashiwa, Chiba, 277-8567, Japan
| | - Fusao Kato
- Department of Neuroscience, The Jikei University School of Medicine, Tokyo, Japan
| | - Ayako M Watabe
- Institute of Clinical Medicine and Research, Research Center for Medical Sciences, The Jikei University School of Medicine, 163-1 Kashiwa-shita, Kashiwa, Chiba, 277-8567, Japan.
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8
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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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9
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Wilson TD, Valdivia S, Khan A, Ahn HS, Adke AP, Martinez Gonzalez S, Sugimura YK, Carrasquillo Y. Dual and Opposing Functions of the Central Amygdala in the Modulation of Pain. Cell Rep 2020; 29:332-346.e5. [PMID: 31597095 PMCID: PMC6816228 DOI: 10.1016/j.celrep.2019.09.011] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 07/27/2019] [Accepted: 09/05/2019] [Indexed: 12/22/2022] Open
Abstract
Pain perception is essential for survival and can be amplified or suppressed by expectations, experiences, and context. The neural mechanisms underlying bidirectional modulation of pain remain largely unknown. Here, we demonstrate that the central nucleus of the amygdala (CeA) functions as a pain rheostat, decreasing or increasing pain-related behaviors in mice. This dual and opposing function of the CeA is encoded by opposing changes in the excitability of two distinct subpopulations of GABAergic neurons that receive excitatory inputs from the parabrachial nucleus (PB). Thus, cells expressing protein kinase C-delta (CeA-PKCδ) are sensitized by nerve injury and increase pain-related responses. In contrast, cells expressing somatostatin (CeA-Som) are inhibited by nerve injury and their activity drives antinociception. Together, these results demonstrate that the CeA can amplify or suppress pain in a cell-type-specific manner, uncovering a previously unknown mechanism underlying bidirectional control of pain in the brain. The brain can bidirectionally influence behavioral responses to painful stimuli. Wilson et al identify a cellular mechanism underlying a pain rheostat system within the forebrain, with activation of CeA-Som neurons attenuating pain-related responses and increases in the activity of CeA-PKCδ neurons promoting amplification of pain-related behaviors following injury.
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Affiliation(s)
- Torri D Wilson
- National Center of Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| | - Spring Valdivia
- National Center of Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| | - Aleisha Khan
- National Center of Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| | - Hye-Sook Ahn
- National Center of Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| | - Anisha P Adke
- National Center of Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| | - Santiago Martinez Gonzalez
- National Center of Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| | - Yae K Sugimura
- National Center of Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States
| | - Yarimar Carrasquillo
- National Center of Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, United States.
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10
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Bowen AJ, Chen JY, Huang YW, Baertsch NA, Park S, Palmiter RD. Dissociable control of unconditioned responses and associative fear learning by parabrachial CGRP neurons. eLife 2020; 9:e59799. [PMID: 32856589 PMCID: PMC7556873 DOI: 10.7554/elife.59799] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 08/28/2020] [Indexed: 12/14/2022] Open
Abstract
Parabrachial CGRP neurons receive diverse threat-related signals and contribute to multiple phases of adaptive threat responses in mice, with their inactivation attenuating both unconditioned behavioral responses to somatic pain and fear-memory formation. Because CGRPPBN neurons respond broadly to multi-modal threats, it remains unknown how these distinct adaptive processes are individually engaged. We show that while three partially separable subsets of CGRPPBN neurons broadly collateralize to their respective downstream partners, individual projections accomplish distinct functions: hypothalamic and extended amygdalar projections elicit assorted unconditioned threat responses including autonomic arousal, anxiety, and freezing behavior, while thalamic and basal forebrain projections generate freezing behavior and, unexpectedly, contribute to associative fear learning. Moreover, the unconditioned responses generated by individual projections are complementary, with simultaneous activation of multiple sites driving profound freezing behavior and bradycardia that are not elicited by any individual projection. This semi-parallel, scalable connectivity schema likely contributes to flexible control of threat responses in unpredictable environments.
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Affiliation(s)
- Anna J Bowen
- Department of Biochemistry, University of WashingtonSeattleUnited States
- Howard Hughes Medical Institute, University of WashingtonSeattleUnited States
- Graduate Program in Neuroscience, University of WashingtonSeattleUnited States
| | - Jane Y Chen
- Department of Biochemistry, University of WashingtonSeattleUnited States
- Howard Hughes Medical Institute, University of WashingtonSeattleUnited States
| | - Y Waterlily Huang
- Department of Biochemistry, University of WashingtonSeattleUnited States
- Howard Hughes Medical Institute, University of WashingtonSeattleUnited States
| | - Nathan A Baertsch
- Center for Integrative Brain Research, Seattle Children’s Research InstituteSeattleUnited States
| | - Sekun Park
- Department of Biochemistry, University of WashingtonSeattleUnited States
- Howard Hughes Medical Institute, University of WashingtonSeattleUnited States
| | - Richard D Palmiter
- Department of Biochemistry, University of WashingtonSeattleUnited States
- Howard Hughes Medical Institute, University of WashingtonSeattleUnited States
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11
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Raver C, Uddin O, Ji Y, Li Y, Cramer N, Jenne C, Morales M, Masri R, Keller A. An Amygdalo-Parabrachial Pathway Regulates Pain Perception and Chronic Pain. J Neurosci 2020; 40:3424-3442. [PMID: 32217613 PMCID: PMC7178908 DOI: 10.1523/jneurosci.0075-20.2020] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 02/07/2023] Open
Abstract
The parabrachial (PB) complex mediates both ascending nociceptive signaling and descending pain modulatory information in the affective/emotional pain pathway. We have recently reported that chronic pain is associated with amplified activity of PB neurons in a rat model of neuropathic pain. Here we demonstrate that similar activity amplification occurs in mice, and that this is related to suppressed inhibition to lateral parabrachial (LPB) neurons from the CeA in animals of either sex. Animals with pain after chronic constriction injury of the infraorbital nerve (CCI-Pain) displayed higher spontaneous and evoked activity in PB neurons, and a dramatic increase in after-discharges, responses that far outlast the stimulus, compared with controls. LPB neurons in CCI-Pain animals showed a reduction in inhibitory, GABAergic inputs. We show that, in both rats and mice, LPB contains few GABAergic neurons, and that most of its GABAergic inputs arise from CeA. These CeA GABA neurons express dynorphin, somatostatin, and/or corticotropin releasing hormone. We find that the efficacy of this CeA-LPB pathway is suppressed in chronic pain. Further, optogenetically stimulating this pathway suppresses acute pain, and inhibiting it, in naive animals, evokes pain behaviors. These findings demonstrate that the CeA-LPB pathway is critically involved in pain regulation, and in the pathogenesis of chronic pain.SIGNIFICANCE STATEMENT We describe a novel pathway, consisting of inhibition by dynorphin, somatostatin, and corticotropin-releasing hormone-expressing neurons in the CeA that project to the parabrachial nucleus. We show that this pathway regulates the activity of pain-related neurons in parabrachial nucleus, and that, in chronic pain, this inhibitory pathway is suppressed, and that this suppression is causally related to pain perception. We propose that this amygdalo-parabrachial pathway is a key regulator of both chronic and acute pain, and a novel target for pain relief.
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Affiliation(s)
- Charles Raver
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Olivia Uddin
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Yadong Ji
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland 21201
| | - Ying Li
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Nathan Cramer
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Carleigh Jenne
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Marisela Morales
- Neuronal Networks Section, Intramural Research Program, National Institute on Drug Abuse, Baltimore, Maryland 21224
| | - Radi Masri
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland 21201
| | - Asaf Keller
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
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12
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Li JN, Sheets PL. Spared nerve injury differentially alters parabrachial monosynaptic excitatory inputs to molecularly specific neurons in distinct subregions of the central amygdala. Pain 2020; 161:166-176. [PMID: 31479066 PMCID: PMC6940027 DOI: 10.1097/j.pain.0000000000001691] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 08/21/2019] [Accepted: 08/21/2019] [Indexed: 12/02/2022]
Abstract
Dissecting the organization of circuit pathways involved in pain affect is pivotal for understanding behavior associated with noxious sensory inputs. The central nucleus of the amygdala (CeA) comprises distinct populations of inhibitory GABAergic neurons expressing a wide range of molecular markers. CeA circuits are associated with aversive learning and nociceptive responses. The CeA receives nociceptive signals directly from the parabrachial nucleus (PBn), contributing to the affective and emotional aspects of pain. Although the CeA has emerged as an important node in pain processing, key questions remain regarding the specific targeting of PBn inputs to different CeA subregions and cell types. We used a multifaceted approach involving transgenic reporter mice, viral vector-mediated optogenetics, and brain slice electrophysiology to delineate cell-type-specific functional organization of the PBn-CeA pathway. Whole-cell patch clamp recordings of molecularly defined CeA neurons while optogenetically driving long-range inputs originating from PBn revealed the direct monosynaptic excitatory inputs from PBn neurons to 3 major subdivisions of the CeA: laterocapsular (CeC), lateral (CeL), and medial (CeM). Direct monosynaptic excitatory inputs from PBn targeted both somatostatin-expressing (SOM+) and corticotropin-releasing hormone expressing (CRH+) neurons in the CeA. We find that monosynaptic PBn input is preferentially organized to molecularly specific neurons in distinct subdivisions of the CeA. The spared nerve injury model of neuropathic pain differentially altered PBn monosynaptic excitatory input to CeA neurons based on molecular identity and topographical location within the CeA. These results provide insight into the functional organization of affective pain pathways and how they are altered by chronic pain.
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Affiliation(s)
- Jun-Nan Li
- 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
| | - Patrick L. Sheets
- 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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13
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Pain-Associated Neural Plasticity in the Parabrachial to Central Amygdala Circuit : Pain Changes the Brain, and the Brain Changes the Pain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1099:157-166. [PMID: 30306523 DOI: 10.1007/978-981-13-1756-9_14] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
In addition to the canonical spino-thalamo-cortical pathway, lines of recently accumulated anatomical and physiological evidence suggest that projections originating in nociception-specific neurons in lamina I of the dorsal horn or the spinal nucleus of the trigeminal nerve to the lateral parabrachial nucleus (LPB) and then to the central amygdala (CeA) play essential roles in the nociception-emotion link and its tightening in chronic pain. With recent advances in the artificial manipulation of central neuronal activity, such as those with optogenetics, it is now possible to address many unanswered questions regarding the molecular and cellular mechanisms underlying the plastic changes in this pathway and their role in the pain chronification process.
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14
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Kappa opioid signaling in the central nucleus of the amygdala promotes disinhibition and aversiveness of chronic neuropathic pain. Pain 2019; 160:824-832. [PMID: 30681985 DOI: 10.1097/j.pain.0000000000001458] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chronic pain is associated with neuroplastic changes in the amygdala that may promote hyper-responsiveness to mechanical and thermal stimuli (allodynia and hyperalgesia) and/or enhance emotional and affective consequences of pain. Stress promotes dynorphin-mediated signaling at the kappa opioid receptor (KOR) in the amygdala and mechanical hypersensitivity in rodent models of functional pain. Here, we tested the hypothesis that KOR circuits in the central nucleus of the amygdala (CeA) undergo neuroplasticity in chronic neuropathic pain resulting in increased sensory and affective pain responses. After spinal nerve ligation (SNL) injury in rats, pretreatment with a long-acting KOR antagonist, nor-binaltorphimine (nor-BNI), subcutaneously or through microinjection into the right CeA, prevented conditioned place preference (CPP) to intravenous gabapentin, suggesting that nor-BNI eliminated the aversiveness of ongoing pain. By contrast, systemic or intra-CeA administration of nor-BNI had no effect on tactile allodynia in SNL animals. Using whole-cell patch-clamp electrophysiology, we found that nor-BNI decreased synaptically evoked spiking of CeA neurons in brain slices from SNL but not sham rats. This effect was mediated through increased inhibitory postsynaptic currents, suggesting tonic disinhibition of CeA output neurons due to increased KOR activity as a possible mechanism promoting ongoing aversive aspects of neuropathic pain. Interestingly, this mechanism is not involved in SNL-induced mechanical allodynia. Kappa opioid receptor antagonists may therefore represent novel therapies for neuropathic pain by targeting aversive aspects of ongoing pain while preserving protective functions of acute pain.
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15
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Pavlenko D, Akiyama T. Why does stress aggravate itch? A possible role of the amygdala. Exp Dermatol 2019; 28:1439-1441. [PMID: 30991457 DOI: 10.1111/exd.13941] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 04/10/2019] [Indexed: 11/30/2022]
Abstract
Stress is the exacerbating factor of itch across patients with chronic itch due to different origins. However, the precise mechanisms behind stress-induced exacerbation of itch remain unknown. Chronic stress induces hyperexcitability of the amygdala, the centre of emotional processing. Recent findings on the itch neuronal pathways support a pivotal role of the amygdala for itch processing. We hypothesized that itch is enhanced by stress through hyperexcitation of the amygdala. Modulation of amygdala activity, therefore, may have therapeutic potential in the treatment of chronic itch.
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Affiliation(s)
- Darya Pavlenko
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, Miami Itch Center, University of Miami, Miami, Florida
| | - Tasuku Akiyama
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, Miami Itch Center, University of Miami, Miami, Florida
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16
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17
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Cell-type specific parallel circuits in the bed nucleus of the stria terminalis and the central nucleus of the amygdala of the mouse. Brain Struct Funct 2019; 224:1067-1095. [PMID: 30610368 DOI: 10.1007/s00429-018-01825-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 12/24/2018] [Indexed: 12/29/2022]
Abstract
The central extended amygdala (EAc) is a forebrain macrosystem which has been widely implicated in reward, fear, anxiety, and pain. Its two key structures, the lateral bed nucleus of the stria terminalis (BSTL) and the central nucleus of the amygdala (CeA), share similar mesoscale connectivity. However, it is not known whether they also share similar cell-specific neuronal circuits. We addressed this question using tract-tracing and immunofluorescence to reveal the EAc microcircuits involving two neuronal populations expressing either protein kinase C delta (PKCδ) or somatostatin (SOM). PKCδ and SOM are expressed predominantly in the dorsal BSTL (BSTLD) and in the lateral/capsular parts of CeA (CeL/C). We found that, in both BSTLD and CeL/C, PKCδ+ cells are the main recipient of extra-EAc inputs from the lateral parabrachial nucleus (LPB), while SOM+ cells constitute the main source of long-range projections to extra-EAc targets, including LPB and periaqueductal gray. PKCδ+ cells can also integrate inputs from the basolateral nucleus of the amygdala or insular cortex. Within EAc, PKCδ+, but not SOM+ neurons, serve as the major source of inputs to the ventral BSTL and to the medial part of CeA. However, both cell types can be involved in mutual connections between BSTLD and CeL/C. These results unveil the pivotal positions of PKCδ+ and SOM+ neurons in organizing parallel cell-specific neuronal circuits within CeA and BSTL, but also between them, which further reinforce the notion of EAc as a structural and functional macrosystem.
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18
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Miyazawa Y, Takahashi Y, Watabe AM, Kato F. Predominant synaptic potentiation and activation in the right central amygdala are independent of bilateral parabrachial activation in the hemilateral trigeminal inflammatory pain model of rats. Mol Pain 2018; 14:1744806918807102. [PMID: 30270724 PMCID: PMC6243415 DOI: 10.1177/1744806918807102] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Nociceptive signals originating in the periphery are conveyed to the brain through specific afferent and ascending pathways. The spino-(trigemino-)parabrachio-amygdaloid pathway is one of the principal pathways mediating signals from nociception-specific ascending neurons to the central amygdala, a limbic structure involved in aversive signal-associated emotional responses, including the emotional aspects of pain. Recent studies suggest that the right and left central amygdala play distinct roles in the regulation of nociceptive responses. Using a latent formalin inflammatory pain model of the rat, we analyzed the right-left differences in synaptic potentiation at the synapses formed between the fibers from the lateral parabrachial nucleus and central amygdala neurons as well as those in the c-Fos expression in the lateral parabrachial nucleus, central amygdala, and the basolateral/lateral amygdala after formalin injection to either the right or left side of the rat upper lip. Although the single-sided formalin injection caused a significant bilateral increase in c-Fos-expressing neurons in the lateral parabrachial nucleus with slight projection-side dependence, the increase in the amplitude of postsynaptic excitatory currents and the number of c-Fos-expressing neurons in the central amygdala occurred predominantly on the right side regardless of the side of the inflammation. Although there was no significant correlation in the number of c-Fos-expressing neurons between the lateral parabrachial nucleus and central amygdala in the formalin-injected animals, these numbers were significantly correlated between the basolateral amygdala and central amygdala. It is thus concluded that the lateral parabrachial nucleus-central amygdala synaptic potentiation reported in various pain models is not a simple Hebbian plasticity in which raised inputs from the lateral parabrachial nucleus cause lateral parabrachial nucleus-central amygdala potentiation but rather an integrative and adaptive response involving specific mechanisms in the right central amygdala.
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Affiliation(s)
- Yuta Miyazawa
- 1 Department of Neuroscience, Jikei University School of Medicine, Tokyo, Japan.,2 Center for Neuroscience of Pain, Jikei University School of Medicine, Tokyo, Japan
| | - Yukari Takahashi
- 1 Department of Neuroscience, Jikei University School of Medicine, Tokyo, Japan.,2 Center for Neuroscience of Pain, Jikei University School of Medicine, Tokyo, Japan
| | - Ayako M Watabe
- 2 Center for Neuroscience of Pain, Jikei University School of Medicine, Tokyo, Japan.,3 Institute of Clinical Medicine and Research, Jikei University School of Medicine, Tokyo, Japan
| | - Fusao Kato
- 1 Department of Neuroscience, Jikei University School of Medicine, Tokyo, Japan.,2 Center for Neuroscience of Pain, Jikei University School of Medicine, Tokyo, Japan
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19
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Pautrat A, Rolland M, Barthelemy M, Baunez C, Sinniger V, Piallat B, Savasta M, Overton PG, David O, Coizet V. Revealing a novel nociceptive network that links the subthalamic nucleus to pain processing. eLife 2018; 7:36607. [PMID: 30149836 PMCID: PMC6136891 DOI: 10.7554/elife.36607] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 08/06/2018] [Indexed: 12/13/2022] Open
Abstract
Pain is a prevalent symptom of Parkinson's disease, and is effectively treated by deep brain stimulation of the subthalamic nucleus (STN). However, the link between pain and the STN remains unclear. In the present work, using in vivo electrophysiology in rats, we report that STN neurons exhibit complex tonic and phasic responses to noxious stimuli. We also show that nociception is altered following lesions of the STN, and characterize the role of the superior colliculus and the parabrachial nucleus in the transmission of nociceptive information to the STN, physiologically from both structures and anatomically in the case of the parabrachial nucleus. We show that STN nociceptive responses are abnormal in a rat model of PD, suggesting their dependence on the integrity of the nigrostriatal dopaminergic system. The STN-linked nociceptive network that we reveal is likely to be of considerable clinical importance in neurological diseases involving a dysfunction of the basal ganglia.
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Affiliation(s)
- Arnaud Pautrat
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Marta Rolland
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Margaux Barthelemy
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Christelle Baunez
- Institut de Neurosciences de la Timone, Aix-Marseille Université, Marseille, France
| | - Valérie Sinniger
- Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France.,Service d'Hépato-Gastroentérologie, CHU Grenoble Alpes, Grenoble, France
| | - Brigitte Piallat
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Marc Savasta
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Paul G Overton
- Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Olivier David
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Veronique Coizet
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
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20
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Kawai Y. Differential Ascending Projections From the Male Rat Caudal Nucleus of the Tractus Solitarius: An Interface Between Local Microcircuits and Global Macrocircuits. Front Neuroanat 2018; 12:63. [PMID: 30087599 PMCID: PMC6066510 DOI: 10.3389/fnana.2018.00063] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/11/2018] [Indexed: 11/18/2022] Open
Abstract
To integrate and broadcast neural information, local microcircuits and global macrocircuits interact within certain specific nuclei of the central nervous system. The structural and functional architecture of this interaction was determined for the caudal nucleus of the tractus solitarius (NTS) at the level of the area postrema (AP), a relay station of peripheral viscerosensory information that is processed and conveyed to brain regions concerned with autonomic-affective and other interoceptive reflexive functions. Axon collaterals of most small NTS cells (soma <150 μm2) establish excitatory or inhibitory local microcircuits likely to control the activity of nearby NTS cells and to transfer peripheral signals to efferent projection neurons. At least two types of cells that constitute efferent pathways from the caudal NTS (cNTS) were distinguished: (1) a greater numbers of small cells, seemingly forming local excitatory microcircuits via recurrent axon collaterals, that project specifically and unidirectionally to the lateral parabrachial nucleus; and (2) a much smaller numbers of cells likely to establish multiple global connections, mostly via the medial forebrain bundle (MFB) or the dorsal longitudinal fascicle (DLF), with a wide range of brain regions, including the ventrolateral medulla (VLM), hypothalamus, central nucleus of the amygdala (ACe), bed nucleus of the stria terminalis (BNST), spinal cord dorsal horn, brainstem reticular formation, locus coeruleus (LC), periaqueductal gray (PAG) and periventricular diencephalon (including the epithalamus). The evidence presented here suggests that distinct cNTS cell types distinguished by projection pattern and related structural and functional features participate differentially in the computation of viscerosensory information and coordination of global macro-networks in a highly organized manner.
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Affiliation(s)
- Yoshinori Kawai
- Department of Anatomy, Jikei University School of Medicine, Tokyo, Japan.,Center for Neuroscience of Pain, Jikei University School of Medicine, Tokyo, Japan
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21
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Holmes NM, Crane JW, Tang M, Fam J, Westbrook RF, Delaney AJ. α 2-adrenoceptor-mediated inhibition in the central amygdala blocks fear-conditioning. Sci Rep 2017; 7:11712. [PMID: 28916748 PMCID: PMC5601913 DOI: 10.1038/s41598-017-12115-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/25/2017] [Indexed: 11/16/2022] Open
Abstract
The central amygdala is critical for the acquisition and expression of fear memories. This region receives a dense innervation from brainstem noradrenergic cell groups and has a high level of α2-adrenoceptor expression. Using whole-cell electrophysiological recordings from rat brain slices, we characterise the role of pre-synaptic α2-adrenoceptor in modulating discrete inhibitory and excitatory connections within both the lateral and medial division of the central amygdala. The selective α2-adrenoceptor agonist clonidine blocked the excitatory input from the pontine parabrachial neurons onto neurons of the lateral central amygdala. In addition, clonidine blocked inhibitory connections from the medial paracapsular intercalated cell mass onto both lateral and medial central amygdala neurons. To examine the behavioural consequence of α2-adrenoceptor-mediated inhibition of these inputs, we infused clonidine into the central amygdala prior to contextual fear-conditioning. In contrast to vehicle-infused rats, clonidine-infused animals displayed reduced levels of freezing 24 hours after training, despite showing no difference in freezing during the training session. These results reveal a role for α2-adrenoceptors within the central amygdala in the modulation of synaptic transmission and the formation of fear-memories. In addition, they provide further evidence for a role of the central amygdala in fear-memory formation.
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Affiliation(s)
- N M Holmes
- School of Psychology, University of New South Wales, Sydney, NSW, 2052, Australia
| | - J W Crane
- School of Biomedical Sciences, Charles Sturt University, Orange, NSW, 2800, Australia
| | - M Tang
- School of Psychology, University of New South Wales, Sydney, NSW, 2052, Australia
| | - J Fam
- School of Psychology, University of New South Wales, Sydney, NSW, 2052, Australia
| | - R F Westbrook
- School of Psychology, University of New South Wales, Sydney, NSW, 2052, Australia
| | - A J Delaney
- School of Biomedical Sciences, Charles Sturt University, Orange, NSW, 2800, Australia.
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22
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Shinohara K, Watabe AM, Nagase M, Okutsu Y, Takahashi Y, Kurihara H, Kato F. Essential role of endogenous calcitonin gene-related peptide in pain-associated plasticity in the central amygdala. Eur J Neurosci 2017; 46:2149-2160. [PMID: 28833700 PMCID: PMC5698701 DOI: 10.1111/ejn.13662] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 08/04/2017] [Accepted: 08/14/2017] [Indexed: 12/16/2022]
Abstract
The role of the neuropeptide calcitonin gene‐related peptide (CGRP) is well established in nociceptive behaviors. CGRP is highly expressed in the projection pathway from the parabrachial nucleus to the laterocapsular region of the central amygdala (CeC), which plays a critical role in relaying nociceptive information. The CeC is a key structure in pain behavior because it integrates and modulates nociceptive information along with other sensory signals. Previous studies have demonstrated that blockade of the amygdalar CGRP‐signaling cascade attenuates nociceptive behaviors in pain models, while CGRP application facilitates amygdalar synaptic transmission and induces pain behaviors. Despite these lines of evidence, it remains unclear whether endogenous CGRP is involved in the development of nociceptive behaviors accompanied with amygdalar plasticity in a peripheral inflammation model in vivo. To directly address this, we utilized a previously generated CGRP knockout (KO) mouse to longitudinally study formalin‐induced plasticity and nociceptive behavior. We found that synaptic potentiation in the right PB‐CeC pathway that was observed in wild‐type mice was drastically attenuated in the CGRP KO mice 6 h post‐inflammation, when acute nociceptive behavior was no longer observed. Furthermore, the bilateral tactile allodynia 6 h post‐inflammation was significantly decreased in the CGRP KO mice. In contrast, the acute nociceptive behavior immediately after the formalin injection was reduced only at 20–25 min post‐injection in the CGRP KO mice. These results suggest that endogenous CGRP contributes to peripheral inflammation‐induced synaptic plasticity in the amygdala, and this plasticity may underlie the exaggerated nociception–emotion linkage in pain chronification.
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Affiliation(s)
- Kei Shinohara
- Department of Neuroscience, Jikei University School of Medicine, Minato-ku, Tokyo, Japan.,Department of Orthopaedic Surgery, Jikei University School of Medicine, Minato-ku, Tokyo, Japan.,Center for Neuroscience of Pain, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Ayako M Watabe
- Department of Neuroscience, Jikei University School of Medicine, Minato-ku, Tokyo, Japan.,Center for Neuroscience of Pain, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Masashi Nagase
- Department of Neuroscience, Jikei University School of Medicine, Minato-ku, Tokyo, Japan.,Center for Neuroscience of Pain, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Yuya Okutsu
- Department of Neuroscience, Jikei University School of Medicine, Minato-ku, Tokyo, Japan.,Department of Orthopaedic Surgery, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Yukari Takahashi
- Department of Neuroscience, Jikei University School of Medicine, Minato-ku, Tokyo, Japan.,Center for Neuroscience of Pain, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Hiroki Kurihara
- Department of Molecular Cell Biology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Fusao Kato
- Department of Neuroscience, Jikei University School of Medicine, Minato-ku, Tokyo, Japan.,Center for Neuroscience of Pain, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
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23
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Yeganeh F, Nasimi A, Hatam M. Interaction of GABA and norepinephrine in the lateral division of the bed nucleus of the stria terminals in anesthetized rat, correlating single-unit and cardiovascular responses. Neuroscience 2017; 356:255-264. [PMID: 28576724 DOI: 10.1016/j.neuroscience.2017.05.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/18/2017] [Accepted: 05/23/2017] [Indexed: 12/23/2022]
Abstract
The bed nucleus of the stria terminalis (BST) consists of multiple anatomically distinct nuclei. The lateral division, which receives dense noradrenergic innervation, has been implicated in cardiovascular regulation and modulation of responses to stress. This study is performed to identify the cardiovascular and single-unit responses of the lateral BST to norepinephrine (NE), involved adrenoceptors, and possible interaction with GABAergic system of the BST in urethane-anesthetized rats. NE, adrenoreceptor antagonists, and GABAA antagonist were microinjected into the lateral division of BST, while arterial pressure (AP), heart rate (HR), and single-unit responses were simultaneously recorded. NE microinjected into the lateral division of BST produced depressor and bradycardic responses. The decrease in AP and HR to NE was blocked by prazosin, an α1-adrenoreceptor antagonist, but not by yohimbine, an α2 antagonist. Furthermore, injections of the GABAA receptor antagonist, bicuculline methiodide (BMI), into the lateral BST abolished the NE-induced depressor and bradycardic responses. We also observed single-unit responses consisting of excitatory and inhibitory responses correlated with cardiovascular function to the microinjection of NE. In conclusion, these data provide the first evidence that microinjection of NE in the lateral division of BST produces depressor and bradycardic responses in urethane-anesthetized rat. The depressor and bradycardiac response are mediated by local α1- but not α2-adrenoceptors. α1-AR activates the GABAergic system within the BST, which in turn produces depressor and bradycardic responses.
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Affiliation(s)
- Fahimeh Yeganeh
- Dept. of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ali Nasimi
- Dept. of Physiology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Masoumeh Hatam
- Dept. of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran.
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24
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Li Z, Yin P, Chen J, Jin S, Liu J, Luo F. CaMKIIα may modulate fentanyl-induced hyperalgesia via a CeLC-PAG-RVM-spinal cord descending facilitative pain pathway in rats. PLoS One 2017; 12:e0177412. [PMID: 28489932 PMCID: PMC5425219 DOI: 10.1371/journal.pone.0177412] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 04/26/2017] [Indexed: 11/30/2022] Open
Abstract
Each of the lateral capsular division of central nucleus of amygdala(CeLC), periaqueductal gray (PAG), rostral ventromedial medulla(RVM) and spinal cord has been proved to contribute to the development of opioid-induced hyperalgesia(OIH). Especially, Ca2+/calmodulin-dependent protein kinase IIα (CaMKIIα) in CeLC and spinal cord seems to play a key role in OIH modulation. However, the pain pathway through which CaMKIIα modulates OIH is not clear. The pathway from CeLC to spinal cord for this modulation was explored in the present study. Mechanical and thermal hyperalgesia were tested by von Frey test or Hargreaves test, respectively. CaMKIIα activity (phospho-CaMKIIα, p-CaMKIIα) was evaluated by western blot analysis. CaMKIIα antagonist (KN93) was micro-infused into CeLC, spinal cord or PAG, respectively, to evaluate its effect on behavioral hyperalgesia and p-CaMKIIα expression in CeLC, PAG, RVM and spinal cord. Then the underlying synaptic mechanism was explored by recording miniature excitatory postsynaptic currents (mEPSCs) on PAG slices using whole-cell voltage-clamp methods. Results showed that inhibition of CeLC, PAG or spinal CaMKIIα activity respectively by KN93, reversed both mechanical and thermal hyperalgesia. Microinjection of KN93 into CeLC decreased p-CaMKIIα expression in CeLC, PAG, RVM and spinal cord; while intrathecal KN93 can only block spinal but not CeLC CaMKIIα activity. KN93 injected into PAG just decreased p-CaMKIIα expression in PAG, RVM and spinal cord, but not in the CeLC. Similarly, whole-cell voltage-clamp recording found the frequency and amplitude of mEPSCs in PAG cells were decreased by KN93 added in PAG slice or micro-infused into CeLC in vivo. These results together with previous findings suggest that CaMKIIα may modulate OIH via a CeLC-PAG-RVM-spinal cord descending facilitative pain pathway.
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Affiliation(s)
- Zhen Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Pingping Yin
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian Chen
- The Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science, State Ethnic Affairs Commission, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, China
| | - Shenglan Jin
- Department of Anesthesiology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jieqiong Liu
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fang Luo
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Activation of the Extracellular Signal-Regulated Kinase in the Amygdale Modulates Fentanyl-Induced Hypersensitivity in Rats. THE JOURNAL OF PAIN 2016; 18:188-199. [PMID: 27838497 DOI: 10.1016/j.jpain.2016.10.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 10/08/2016] [Accepted: 10/24/2016] [Indexed: 11/23/2022]
Abstract
Opioid-induced hyperalgesia (OIH) is one of the major problems associated with use of opioids in perioperative and chronic pain management. The mechanism underlying this paradoxical phenomenon needs to be fully elucidated. Laterocapsular division of the central nucleus of amygdale (CeLC) has emerged as an important brain center for pain modulation, so we hypothesize that the activation of extracellular signal-regulated kinase (ERK) in CeLC may modulate OIH through strengthening synaptic transmission between neurons in the CeLC. Phospho-ERK in CeLC was first found to be increased significantly in OIH rats induced by repeated subcutaneous injection of fentanyl. Blockade of this fentanyl-induced ERK activation by microinjection of U0126, an ERK inhibitor, into the CeLC reversed the behavioral hypersensitivity in a dose-dependent manner. In vitro whole-cell recordings evaluating the change in synaptic transmission found that the frequency as well as amplitude of miniature excitatory postsynaptic currents recorded on CeLC neurons from OIH rats were fundamentally increased and were completely reversed by acutely applied U0126 (10 μM in the recording well). In vivo microinjection of U0126 into the CeLC reversed the spinal long-term potentiation in OIH rats. These results showed that fentanyl-induced hypersensitivity may occur partly through the mechanism of ERK activation and followed by the strengthening of synaptic transmission in CeLC neurons. PERSPECTIVE This study provides evidence that ERK in the laterocapsular division of the CeLC is a key contributor to the development of fentanyl-induced hypersensitivity. Targeting the superspinal central CeLC can inhibit spinal long-term potentiation and alleviate behavioral hyperreflexia induced by fentanyl.
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Li Z, Li C, Yin P, Wang ZJ, Luo F. Inhibition of CaMKIIα in the Central Nucleus of Amygdala Attenuates Fentanyl-Induced Hyperalgesia in Rats. J Pharmacol Exp Ther 2016; 359:82-9. [PMID: 27451410 DOI: 10.1124/jpet.116.233817] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 07/18/2016] [Indexed: 12/21/2022] Open
Abstract
Opioid-induced hyperalgesia (OIH) is a less-studied phenomenon that has been reported in both preclinical and clinical studies. Although the underlying cause is not entirely understood, OIH is a real-life problem that affects millions of patients on a daily basis. Research has implicated the important contribution of Ca(2+)/calmodulin-dependent protein kinase IIα (CaMKIIα) to OIH at the level of spinal nociceptors. To expand our understanding of the entire brain circuitry driving OIH, in this study we investigated the role of CaMKIIα in the laterocapcular division of the central amygdala (CeLC), the conjunctive point between the spinal cord and rostro-ventral medulla. OIH was produced by repeated fentanyl administration in the rat. Correlating with the development of mechanical allodynia and thermal hyperalgesia, CaMKIIα activity was significantly elevated in the CeLC in OIH. In addition, the frequency and amplitude of spontaneous miniature excitatory postsynaptic currents (mEPSCs) in CeLC neurons were significantly increased in OIH. 2-[N-(2-hidroxyethyl)-N-(4-methoxy-benzenesulfonyl)]-amino-N-(4-chlorocinnamyl)-N-methylbenzylamine, a CaMKIIα inhibitor, dose dependently reversed sensory hypersensitivity, activation of CeLC CaMKIIα, and mEPSCs in OIH. Taken together, our data for the first time implicate a critical role of CeLC CaMKIIα in OIH.
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Affiliation(s)
- Zhen Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (Z.L., P.Y, F.L.); Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science, State Ethnic Affairs Commission, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, China (C. L.); and Department of Biopharmaceutical Sciences and Cancer Center, University of Illinois, Chicago, Illinois (Z.J.W)
| | - Chenhong Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (Z.L., P.Y, F.L.); Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science, State Ethnic Affairs Commission, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, China (C. L.); and Department of Biopharmaceutical Sciences and Cancer Center, University of Illinois, Chicago, Illinois (Z.J.W)
| | - Pingping Yin
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (Z.L., P.Y, F.L.); Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science, State Ethnic Affairs Commission, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, China (C. L.); and Department of Biopharmaceutical Sciences and Cancer Center, University of Illinois, Chicago, Illinois (Z.J.W)
| | - Zaijie Jim Wang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (Z.L., P.Y, F.L.); Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science, State Ethnic Affairs Commission, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, China (C. L.); and Department of Biopharmaceutical Sciences and Cancer Center, University of Illinois, Chicago, Illinois (Z.J.W)
| | - Fang Luo
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (Z.L., P.Y, F.L.); Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science, State Ethnic Affairs Commission, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, China (C. L.); and Department of Biopharmaceutical Sciences and Cancer Center, University of Illinois, Chicago, Illinois (Z.J.W)
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Sugimura YK, Takahashi Y, Watabe AM, Kato F. Synaptic and network consequences of monosynaptic nociceptive inputs of parabrachial nucleus origin in the central amygdala. J Neurophysiol 2016; 115:2721-39. [PMID: 26888105 PMCID: PMC4922599 DOI: 10.1152/jn.00946.2015] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/15/2016] [Indexed: 01/04/2023] Open
Abstract
A large majority of neurons in the superficial layer of the dorsal horn projects to the lateral parabrachial nucleus (LPB). LPB neurons then project to the capsular part of the central amygdala (CeA; CeC), a key structure underlying the nociception-emotion link. LPB-CeC synaptic transmission is enhanced in various pain models by using electrical stimulation of putative fibers of LPB origin in brain slices. However, this approach has limitations for examining direct monosynaptic connections devoid of directly stimulating fibers from other structures and local GABAergic neurons. To overcome these limitations, we infected the LPB of rats with an adeno-associated virus vector expressing channelrhodopsin-2 and prepared coronal and horizontal brain slices containing the amygdala. We found that blue light stimulation resulted in monosynaptic excitatory postsynaptic currents (EPSCs), with very small latency fluctuations, followed by a large polysynaptic inhibitory postsynaptic current in CeC neurons, regardless of the firing pattern type. Intraplantar formalin injection at 24 h before slice preparation significantly increased EPSC amplitude in late firing-type CeC neurons. These results indicate that direct monosynaptic glutamatergic inputs from the LPB not only excite CeC neurons but also regulate CeA network signaling through robust feed-forward inhibition, which is under plastic modulation in response to persistent inflammatory pain.
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Affiliation(s)
- Yae K Sugimura
- Department of Neuroscience, The Jikei University School of Medicine, Minato, Tokyo, Japan; Center for Neuroscience of Pain, The Jikei University School of Medicine, Minato, Tokyo, Japan; Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Yukari Takahashi
- Department of Neuroscience, The Jikei University School of Medicine, Minato, Tokyo, Japan; Center for Neuroscience of Pain, The Jikei University School of Medicine, Minato, Tokyo, Japan
| | - Ayako M Watabe
- Department of Neuroscience, The Jikei University School of Medicine, Minato, Tokyo, Japan; Center for Neuroscience of Pain, The Jikei University School of Medicine, Minato, Tokyo, Japan; Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan; and Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Fusao Kato
- Department of Neuroscience, The Jikei University School of Medicine, Minato, Tokyo, Japan; Center for Neuroscience of Pain, The Jikei University School of Medicine, Minato, Tokyo, Japan; Nagoya University Graduate School of Medicine, Nagoya, Japan
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Delaney AJ, Crane JW. Presynaptic GABAB receptors reduce transmission at parabrachial synapses in the lateral central amygdala by inhibiting N-type calcium channels. Sci Rep 2016; 6:19255. [PMID: 26755335 PMCID: PMC4709695 DOI: 10.1038/srep19255] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 12/07/2015] [Indexed: 11/20/2022] Open
Abstract
The nocioceptive information carried by neurons of the pontine parabrachial nucleus to neurons of the lateral division of the central amydala (CeA-L) is thought to contribute to the affective components of pain and is required for the formation of conditioned-fear memories. Importantly, excitatory transmission between parabrachial axon terminals and CeA-L neurons can be inhibited by a number of presynaptic receptors linked to Gi/o-type G-proteins, including α2-adrenoceptors and GABAB receptors. While the intracellular signalling pathway responsible for α2-adrenoceptor inhibition of synaptic transmission at this synapse is known, the mechanism by which GABAB receptors inhibits transmission has not been determined. The present study demonstrates that activation of presynaptic GABAB receptors reduces excitatory transmission between parabrachial axon terminals and CeA-L neurons by inhibiting N-type calcium channels. While the involvement of Gβγ subunits in mediating the inhibitory effects of GABAB receptors on N-type calcium channels is unclear, this inhibition does not involve Gβγ-independent activation of pp60C-src tyrosine kinase. The results of this study further enhance our understanding of the modulation of the excitatory input from parabrachial axon terminals to CeA-L neurons and indicate that presynaptic GABAB receptors at this synapse could be valuable therapeutic targets for the treatment of fear- and pain-related disorders.
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Affiliation(s)
- A J Delaney
- School of Biomedical Sciences, Charles Sturt University, NSW, Australia
| | - J W Crane
- School of Biomedical Sciences, Charles Sturt University, NSW, Australia
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Han S, Soleiman MT, Soden ME, Zweifel LS, Palmiter RD. Elucidating an Affective Pain Circuit that Creates a Threat Memory. Cell 2015; 162:363-374. [PMID: 26186190 DOI: 10.1016/j.cell.2015.05.057] [Citation(s) in RCA: 287] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/28/2015] [Accepted: 05/27/2015] [Indexed: 12/24/2022]
Abstract
Animals learn to avoid harmful situations by associating a neutral stimulus with a painful one, resulting in a stable threat memory. In mammals, this form of learning requires the amygdala. Although pain is the main driver of aversive learning, the mechanism that transmits pain signals to the amygdala is not well resolved. Here, we show that neurons expressing calcitonin gene-related peptide (CGRP) in the parabrachial nucleus are critical for relaying pain signals to the central nucleus of amygdala and that this pathway may transduce the affective motivational aspects of pain. Genetic silencing of CGRP neurons blocks pain responses and memory formation, whereas their optogenetic stimulation produces defensive responses and a threat memory. The pain-recipient neurons in the central amygdala expressing CGRP receptors are also critical for establishing a threat memory. The identification of the neural circuit conveying affective pain signals may be pertinent for treating pain conditions with psychiatric comorbidities.
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Affiliation(s)
- Sung Han
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Matthew T Soleiman
- Graduate Program in Neuroscience, University of Washington, Seattle, WA 98195, USA
| | - Marta E Soden
- Departments of Psychiatry and Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Larry S Zweifel
- Departments of Psychiatry and Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Richard D Palmiter
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Graduate Program in Neuroscience, University of Washington, Seattle, WA 98195, USA.
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Liu CY, Lee ML, Yang CS, Chen CM, Min MY, Yang HW. Morphological and physiological evidence of a synaptic connection between the lateral parabrachial nucleus and neurons in the A7 catecholamine cell group in rats. J Biomed Sci 2015; 22:79. [PMID: 26385355 PMCID: PMC4575445 DOI: 10.1186/s12929-015-0179-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/20/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The descending noradrenergic (NAergic) system is one of the important endogenous analgesia systems. It has been suggested that noxious stimuli could activate descending NAergic system; nevertheless, the underlying neuronal circuit remains unclear. As NAergic neurons in the A7 catecholamine cell group (A7) are a part of the descending NAergic system and the lateral parabrachial nucleus (LPB) is an important brainstem structure that relays ascending nociceptive signal, we aimed to test whether LPB neurons have direct synaptic contact with NAergic A7 neurons. RESULTS Stereotaxic injections of an anterograde tracer, biotinylated dextran-amine (BDA), were administered to LPB in rats. The BDA-labeled axonal terminals that have physical contacts with tyrosine hydroxylase-positive (presumed noadrenergic) neurons were identified in A7. Consistent with these morphological observations, the excitatory synaptic currents (EPSCs) were readily evoked in NAergic A7 neurons by extracellular stimulation of LPB. The EPSCs evoked by LPB stimulation were blocked by CNQX, a non-NMDA receptor blocker, and AP5, a selective NMDA receptor blocker, showing that LPB-A7 synaptic transmission is glutamatergic. Moreover, the amplitude of LPB-A7 EPSCs was significantly attenuated by DAMGO, a selective μ-opioid receptor agonist, which was associated with an increase in paired-pulse ratio. CONCLUSIONS Taken together, the above results showed direct synaptic connections between LPB and A7 catecholamine cell group, the function of which is subject to presynaptic modulation by μ-opioid receptors.
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Affiliation(s)
- Chia-Yi Liu
- Department of Life Sciences, and Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan. .,Department of Nursing, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan.
| | - Meng-Lam Lee
- Department of Biomedical Sciences, Chung Shan Medical University, 110, Chien-Kuo N. Rd, Sec. 1, Taichung, 402, Taiwan. .,Department of Medical Research, Chung Shan Medical University, Taichung, Taiwan.
| | - Chi-Sheng Yang
- Department of Nursing, Hungkuang University, Taichung, Taiwan.
| | - Chuan-Mu Chen
- Department of Life Sciences, and Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan. .,Rong Hsing Research Center for Translational Medicine, and the iEGG Center, National Chung Hsing University, Taichung, Taiwan.
| | - Ming-Yuan Min
- Department of Life Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan.
| | - Hsiu-Wen Yang
- Department of Biomedical Sciences, Chung Shan Medical University, 110, Chien-Kuo N. Rd, Sec. 1, Taichung, 402, Taiwan. .,Department of Medical Research, Chung Shan Medical University, Taichung, Taiwan.
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31
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Sato M, Ito M, Nagase M, Sugimura YK, Takahashi Y, Watabe AM, Kato F. The lateral parabrachial nucleus is actively involved in the acquisition of fear memory in mice. Mol Brain 2015; 8:22. [PMID: 25888401 PMCID: PMC4377188 DOI: 10.1186/s13041-015-0108-z] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 03/05/2015] [Indexed: 12/31/2022] Open
Abstract
Background Pavlovian fear conditioning is a form of learning accomplished by associating a conditioned stimulus (CS) and an unconditioned stimulus (US). While CS–US associations are generally thought to occur in the amygdala, the pathway mediating US signal processing has only been partially identified. The external part of the pontine lateral parabrachial nucleus (elPB) is well situated for providing US nociceptive information to the central amygdala (CeA), which was recently revealed to play a primary role in fear acquisition. Therefore, we manipulated the elPB activity to examine its role in the regulation of fear learning. Results First, we transiently inactivate the elPB during the acquisition of fear memory. Mice received bilateral elPB injections of the GABAA agonist muscimol (MUS) or phosphate-buffered saline (drug control), with bilateral misplacement of MUS defined as a placement control group. After the injection, mice were conditioned with a pure tone and foot-shock. On a memory retrieval test on day 2, the freezing ratio was significantly lower in the MUS group compared with that in the drug control or placement control groups. A second retrieval test using a pip tone on day 4 following de novo training on day 3, resulted in significant freezing with no group differences, indicating integrity of fear learning and a temporary limited effect of MUS. Next, we examined whether selectively activating the elPB-CeC pathway is sufficient to induce fear learning when paired with CS. Mice with channelrhodopsin2 (ChR2) expressed in the elPB received a pure tone (CS) in association with optical stimulation in the CeA (CS-LED paired group). On the retrieval test, CS-LED paired mice exhibited significantly higher freezing ratios evoked by CS presentation compared with both control mice receiving optical stimulation immediately after being placed in the shock chamber and exposed to the CS much later (immediate shock group) and those expressing only GFP (GFP control group). These results suggest that selective stimulation of the elPB-CeC pathway substitutes for the US to induce fear learning. Conclusions The elPB activity is necessary and sufficient to trigger fear learning, likely as a part of the pathway transmitting aversive signals to the CeA.
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Affiliation(s)
- Masaru Sato
- Department of Neuroscience, Jikei University School of Medicine, Tokyo, 105-8461, Japan. .,Department of Anesthesiology, Jikei University School of Medicine, Tokyo, 105-8461, Japan.
| | - Mariko Ito
- Department of Neuroscience, Jikei University School of Medicine, Tokyo, 105-8461, Japan. .,Department of Anesthesiology, Jikei University School of Medicine, Tokyo, 105-8461, Japan.
| | - Masashi Nagase
- Department of Neuroscience, Jikei University School of Medicine, Tokyo, 105-8461, Japan.
| | - Yae K Sugimura
- Department of Neuroscience, Jikei University School of Medicine, Tokyo, 105-8461, Japan.
| | - Yukari Takahashi
- Department of Neuroscience, Jikei University School of Medicine, Tokyo, 105-8461, Japan.
| | - Ayako M Watabe
- Department of Neuroscience, Jikei University School of Medicine, Tokyo, 105-8461, Japan. .,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Kawaguchi, Saitama, 332-0012, Japan. .,Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Fusao Kato
- Department of Neuroscience, Jikei University School of Medicine, Tokyo, 105-8461, Japan. .,Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
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Lu YC, Chen YZ, Wei YY, He XT, Li X, Hu W, Yanagawa Y, Wang W, Wu SX, Dong YL. Neurochemical properties of the synapses between the parabrachial nucleus-derived CGRP-positive axonal terminals and the GABAergic neurons in the lateral capsular division of central nucleus of amygdala. Mol Neurobiol 2014; 51:105-18. [PMID: 24794145 DOI: 10.1007/s12035-014-8713-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 04/09/2014] [Indexed: 11/28/2022]
Abstract
The lateral capsular division of central nucleus of amygdala (CeC) contains neurons using γ-amino butyric acid (GABA) as the predominant neurotransmitter and expresses abundant calcitonin gene-related peptide (CGRP)-positive terminals. However, the relationship between them has not been revealed yet. Using GAD67-green fluorescent protein (GFP) knock-in mouse, we investigated the neurochemical features of synapses between CGRP-positive terminals and GABAergic neurons within CeC and the potential involvement of CGRP1 receptor by combining fluorescent in situ hybridization for CGRP1 receptor mRNA with immunofluorescent histochemistry for GFP and CGRP. The ultrastructures of these synapses were investigated with pre-embedding electron microscopy for GFP and CGRP. We found that some GABAergic neurons in the CeC received parabrachial nucleus (PBN) derived CGRP innervations and some of these GABAergic neurons can be activated by subcutaneous injection of formalin. Moreover, more than 90 % GABAergic neurons innervated by CGRP-positive terminal also express CGRP1 receptor mRNA. The CGRP-positive fibers made symmetric synapses onto the GABAergic somata, and asymmetric synapses onto the GABA-LI dendritic shafts and spines. This study provides direct ultrastructural evidences for the synaptic contacts between CGRP-positive terminals and GABAergic neurons within the CeC, which may underlie the pain-related neural pathway from PBN to CeC and be involved in the chronic pain modulation.
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Affiliation(s)
- Ya-Cheng Lu
- Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, People's Republic of China
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Strobel C, Hunt S, Sullivan R, Sun J, Sah P. Emotional regulation of pain: the role of noradrenaline in the amygdala. SCIENCE CHINA-LIFE SCIENCES 2014; 57:384-90. [PMID: 24643418 DOI: 10.1007/s11427-014-4638-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 02/25/2014] [Indexed: 01/22/2023]
Abstract
The perception of pain involves the activation of the spinal pathway as well as the supra-spinal pathway, which targets brain regions involved in affective and cognitive processes. Pain and emotions have the capacity to influence each other reciprocally; negative emotions, such as depression and anxiety, increase the risk for chronic pain, which may lead to anxiety and depression. The amygdala is a key-player in the expression of emotions, receives direct nociceptive information from the parabrachial nucleus, and is densely innervated by noradrenergic brain centers. In recent years, the amygdala has attracted increasing interest for its role in pain perception and modulation. In this review, we will give a short overview of structures involved in the pain pathway, zoom in to afferent and efferent connections to and from the amygdala, with emphasis on the direct parabrachio-amygdaloid pathway and discuss the evidence for amygdala's role in pain processing and modulation. In addition to the involvement of the amygdala in negative emotions during the perception of pain, this brain structure is also a target site for many neuromodulators to regulate the perception of pain. We will end this article with a short review on the effects of noradrenaline and its role in hypoalgesia and analgesia.
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Affiliation(s)
- Cornelia Strobel
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, 4072, Australia
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Sink KS, Davis M, Walker DL. CGRP antagonist infused into the bed nucleus of the stria terminalis impairs the acquisition and expression of context but not discretely cued fear. Learn Mem 2013; 20:730-9. [PMID: 24255102 PMCID: PMC3834624 DOI: 10.1101/lm.032482.113] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Calcitonin gene-related peptide (CGRP) infusions into the bed nucleus of the stria terminalis (BNST) evoke increases in startle amplitude and increases in anxiety-like behavior in the plus maze. Conversely, intra-BNST infusions of the CGRP antagonist CGRP8–37 block unconditioned startle increases produced by fox odor. Here we evaluate the contribution of CGRP signaling in the BNST to the development and expression of learned fear. Rats received five pairings of a 3.7-sec light and footshock and were tested for fear-potentiated startle one or more days later. Neither pre-training (Experiment 1) nor pre-test (Experiment 2) infusions of the CGRP antagonist CGRP8–37 (800 ng/BNST) disrupted fear-potentiated startle to the 3.7-sec visual cue. However, in both experiments, CGRP8–37 infusions disrupted baseline startle increases that occurred when rats were tested in the same context as that in which they previously received footshock (Experiment 3). Intra-BNST CGRP8–37 infusions did not disrupt shock-evoked corticosterone release (Experiment 4). These data confirm previous findings implicating BNST CGRP receptors in fear and anxiety. They extend those results by showing an important contribution to learned fear and, specifically, to fear evoked by a shock-associated context rather than a discrete cue. This pattern is consistent with previous models of BNST function that have posited a preferential role in sustained anxiety as opposed to phasic fear responses. More generally, the results add to a growing body of evidence indicating behaviorally, possibly clinically, relevant modulation of BNST function by neuroactive peptides.
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Affiliation(s)
- Kelly S Sink
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA
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Ren W, Kiritoshi T, Grégoire S, Ji G, Guerrini R, Calo G, Neugebauer V. Neuropeptide S: a novel regulator of pain-related amygdala plasticity and behaviors. J Neurophysiol 2013; 110:1765-81. [PMID: 23883857 PMCID: PMC3798934 DOI: 10.1152/jn.00874.2012] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 07/18/2013] [Indexed: 12/12/2022] Open
Abstract
Amygdala plasticity is an important contributor to the emotional-affective dimension of pain. Recently discovered neuropeptide S (NPS) has anxiolytic properties through actions in the amygdala. Behavioral data also suggest antinociceptive effects of centrally acting NPS, but site and mechanism of action remain to be determined. This is the first electrophysiological analysis of pain-related NPS effects in the brain. We combined whole cell patch-clamp recordings in brain slices and behavioral assays to test the hypothesis that NPS activates synaptic inhibition of amygdala output to suppress pain behavior in an arthritis pain model. Recordings of neurons in the laterocapsular division of the central nucleus (CeLC), which serves pain-related amygdala output functions, show that NPS inhibited the enhanced excitatory drive [monosynaptic excitatory postsynaptic currents (EPSCs)] from the basolateral amygdala (BLA) in the pain state. As shown by miniature EPSC analysis, the inhibitory effect of NPS did not involve direct postsynaptic action on CeLC neurons but rather a presynaptic, action potential-dependent network mechanism. Indeed, NPS increased external capsule (EC)-driven synaptic inhibition of CeLC neurons through PKA-dependent facilitatory postsynaptic action on a cluster of inhibitory intercalated (ITC) cells. NPS had no effect on BLA neurons. High-frequency stimulation (HFS) of excitatory EC inputs to ITC cells also inhibited synaptic activation of CeLC neurons, providing further evidence that ITC activation can control amygdala output. The cellular mechanisms by which EC-driven synaptic inhibition controls CeLC output remain to be determined. Administration of NPS into ITC, but not CeLC, also inhibited vocalizations and anxiety-like behavior in arthritic rats. A selective NPS receptor antagonist ([d-Cys(tBu)(5)]NPS) blocked electrophysiological and behavioral effects of NPS. Thus NPS is a novel tool to control amygdala output and pain-related affective behaviors through a direct action on inhibitory ITC cells.
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Affiliation(s)
- Wenjie Ren
- Department of Neuroscience and Cell Biology, The University of Texas Medical Branch, Galveston, Texas
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Abstract
In addition to its neurotrophic role, brain-derived neurotrophic factor (BDNF) is involved in a wide array of functions, including anxiety and pain. The central amygdaloid nucleus (CeA) contains a high concentration of BDNF in terminals, originating from the pontine parabrachial nucleus. Since the spino-parabrachio-amygdaloid neural pathway is known to convey nociceptive information, we hypothesized a possible involvement of BDNF in supraspinal pain-related processes. To test this hypothesis, we generated localized deletion of BDNF in the parabrachial nucleus using local bilateral injections of adeno-associated viruses in adult floxed-BDNF mice. Basal thresholds of thermal and mechanical nociceptive responses were not altered by BDNF loss and no behavioural deficit was noticed in anxiety and motor tests. However, BDNF-deleted animals displayed a major decrease in the analgesic effect of morphine. In addition, intra-CeA injections of the BDNF scavenger TrkB-Fc in control mice also decreased morphine-induced analgesia. Finally, the number of c-Fos immunoreactive nuclei after acute morphine injection was decreased by 45% in the extended amygdala of BDNF-deleted animals. The absence of BDNF in the parabrachial nucleus thus altered the parabrachio-amygdaloid pathway. Overall, our study provides evidence that BDNF produced in the parabrachial nucleus modulates the functions of the parabrachio-amygdaloid pathway in opiate analgesia.
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Veinante P, Yalcin I, Barrot M. The amygdala between sensation and affect: a role in pain. J Mol Psychiatry 2013; 1:9. [PMID: 25408902 PMCID: PMC4223879 DOI: 10.1186/2049-9256-1-9] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 05/11/2013] [Indexed: 01/15/2023] Open
Abstract
The amygdala is a structure of the temporal lobe thought to be involved in assigning emotional significance to environmental information and triggering adapted physiological, behavioral and affective responses. A large body of literature in animals and human implicates the amygdala in fear. Pain having a strong affective and emotional dimension, the amygdala, especially its central nucleus (CeA), has also emerged in the last twenty years as key element of the pain matrix. The CeA receives multiple nociceptive information from the brainstem, as well as highly processed polymodal information from the thalamus and the cerebral cortex. It also possesses the connections that allow influencing most of the descending pain control systems as well as higher centers involved in emotional, affective and cognitive functions. Preclinical studies indicate that the integration of nociceptive inputs in the CeA only marginally contributes to sensory-discriminative components of pain, but rather contributes to associated behavior and affective responses. The CeA doesn’t have a major influence on responses to acute nociception in basal condition, but it induces hypoalgesia during aversive situation, such as stress or fear. On the contrary, during persistent pain states (inflammatory, visceral, neuropathic), a long-lasting functional plasticity of CeA activity contributes to an enhancement of the pain experience, including hyperalgesia, aversive behavioral reactions and affective anxiety-like states.
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Affiliation(s)
- Pierre Veinante
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212, Centre National de la Recherche Scientifique, 21 Rue René Descartes, 67084 Strasbourg Cedex, France ; Université de Strasbourg, 21 Rue René Descartes, 67084 Strasbourg Cedex, France
| | - Ipek Yalcin
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212, Centre National de la Recherche Scientifique, 21 Rue René Descartes, 67084 Strasbourg Cedex, France ; Université de Strasbourg, 21 Rue René Descartes, 67084 Strasbourg Cedex, France
| | - Michel Barrot
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212, Centre National de la Recherche Scientifique, 21 Rue René Descartes, 67084 Strasbourg Cedex, France ; Université de Strasbourg, 21 Rue René Descartes, 67084 Strasbourg Cedex, France
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Watabe AM, Ochiai T, Nagase M, Takahashi Y, Sato M, Kato F. Synaptic potentiation in the nociceptive amygdala following fear learning in mice. Mol Brain 2013; 6:11. [PMID: 23452928 PMCID: PMC3606120 DOI: 10.1186/1756-6606-6-11] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 02/26/2013] [Indexed: 12/23/2022] Open
Abstract
Background Pavlovian fear conditioning is a classical form of associative learning, which depends on associative synaptic plasticity in the amygdala. Recent findings suggest that the central amygdala (CeA) plays an active role in the acquisition of fear learning. However, little is known about the synaptic properties of the CeA in fear learning. The capsular part of the central amygdala (CeC) receives direct nociceptive information from the external part of the lateral parabrachial nucleus (lPB), as well as highly processed polymodal signals from the basolateral nucleus of the amygdala (BLA). Therefore, we focused on CeC as a convergence point for polymodal BLA signals and nociceptive lPB signals, and explored the synaptic regulation of these pathways in fear conditioning. Results In this study, we show that fear conditioning results in synaptic potentiation in both lPB-CeC and BLA-CeC synapses. This potentiation is dependent on associative fear learning, rather than on nociceptive or sensory experience, or fear memory retrieval. The synaptic weight of the lPB-CeC and BLA-CeC pathways is correlated in fear-conditioned mice, suggesting that fear learning may induce activity-dependent heterosynaptic interactions between lPB-CeC and BLA-CeC pathways. This synaptic potentiation is associated with both postsynaptic and presynaptic changes in the lPB-CeC and BLA-CeC synapses. Conclusions These results indicate that the CeC may provide an important locus of Pavlovian association, integrating direct nociceptive signals with polymodal sensory signals. In addition to the well-established plasticity of the lateral amygdala, the multi-step nature of this association system contributes to the highly orchestrated tuning of fear learning.
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Affiliation(s)
- Ayako M Watabe
- Department of Neuroscience, Jikei University School of Medicine, Tokyo 105-8461, Japan.
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Nakao A, Takahashi Y, Nagase M, Ikeda R, Kato F. Role of capsaicin-sensitive C-fiber afferents in neuropathic pain-induced synaptic potentiation in the nociceptive amygdala. Mol Pain 2012; 8:51. [PMID: 22776418 PMCID: PMC3464693 DOI: 10.1186/1744-8069-8-51] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 07/09/2012] [Indexed: 12/04/2022] Open
Abstract
Background Neurons in the capsular part of the central nucleus of the amygdala (CeC), a region also called "nociceptive amygdala," receive nociceptive information from the dorsal horn via afferent pathways relayed from the lateral parabrachial nucleus (LPB). As the central amygdala is known to be involved in the acquisition and expression of emotion, this pathway is thought to play central roles in the generation of affective responses to nociceptive inputs. Excitatory synaptic transmission between afferents arising from the LPB and these CeC neurons is potentiated in arthritic, visceral, neuropathic, inflammatory and muscle pain models. In neuropathic pain models following spinal nerve ligation (SNL), in which we previously showed a robust LPB-CeC potentiation, the principal behavioral symptom is tactile allodynia triggered by non-C-fiber low-threshold mechanoreceptor afferents. Conversely, recent anatomical studies have revealed that most of the spinal neurons projecting to the LPB receive C-fiber afferent inputs. Here, we examined the hypothesis that these C-fiber-mediated inputs are necessary for the full establishment of robust synaptic potentiation of LPB-CeC transmission in the rats with neuropathic pain. Results Postnatal capsaicin treatment, which has been shown to denervate the C-fibers expressing transient receptor potential vanilloid type-1 (TRPV1) channels, completely abolished eye-wiping responses to capsaicin eye instillation in rats, but this treatment did not affect mechanical allodynia in the nerve-ligated animals. However, the postnatal capsaicin treatment prevented LPB-CeC synaptic potentiation after SNL, unlike in the vehicle-treated rats, primarily due to the decreased incidence of potentiated transmission by elimination of TRPV1-expressing C-fiber afferents. Conclusions C-fiber-mediated afferents in the nerve-ligated animals may be a required facilitator of the establishment of nerve injury-evoked synaptic potentiation in the CeC. These inputs might play essential roles in the chronic pain-induced plastic changes in the central network linking nociception and negative emotion.
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Affiliation(s)
- Ayano Nakao
- Laboratory of Neurophysiology, Department of Neuroscience, Jikei University School of Medicine, Minato-ku, Tokyo 105-8461, Japan
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Dong YL, Fukazawa Y, Wang W, Kamasawa N, Shigemoto R. Differential postsynaptic compartments in the laterocapsular division of the central nucleus of amygdala for afferents from the parabrachial nucleus and the basolateral nucleus in the rat. J Comp Neurol 2011; 518:4771-91. [PMID: 20963828 DOI: 10.1002/cne.22487] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Neurons in the laterocapsular division of the central nucleus of the amygdala (CeC), which is known as the "nociceptive amygdala," receive glutamatergic inputs from the parabrachial nucleus (PB) and the basolateral nucleus of amygdala (BLA), which convey nociceptive information from the dorsal horn of the spinal cord and polymodal information from the thalamus and cortex, respectively. Here, we examined the ultrastructural properties of PB- and BLA-CeC synapses identified with EGFP-expressing lentivirus in rats. In addition, the density of synaptic AMPA receptors (AMPARs) on CeC neurons was studied by using highly sensitive SDS-digested freeze-fracture replica labeling (SDS-FRL). Afferents from the PB made asymmetrical synapses mainly on dendritic shafts (88%), whereas those from the BLA were on dendritic spines (81%). PB-CeC synapses in dendritic shafts were significantly larger (median 0.072 μm(2)) than BLA-CeC synapses in spines (median 0.058 μm(2); P = 0.02). The dendritic shafts that made synapses with PB fibers were also significantly larger than those that made synapses with BLA fibers, indicating that the PB fibers make synapses on more proximal parts of dendrites than the BLA fibers. SDS-FRL revealed that almost all excitatory postsynaptic sites have AMPARs in the CeC. The density of AMPAR-specific gold particles in individual synapses was significantly higher in spine synapses (median 510 particles/μm(2)) than in shaft synapses (median 427 particles/μm(2); P = 0.01). These results suggest that distinct synaptic impacts from PB- and BLA-CeC pathways contribute to the integration of nociceptive and polymodal information in the CeC.
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Affiliation(s)
- Yu-Lin Dong
- Division of Cerebral Structure, National Institute for Physiological Sciences, Okazaki, Japan.
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Adedoyin MO, Vicini S, Neale JH. Endogenous N-acetylaspartylglutamate (NAAG) inhibits synaptic plasticity/transmission in the amygdala in a mouse inflammatory pain model. Mol Pain 2010; 6:60. [PMID: 20860833 PMCID: PMC3152775 DOI: 10.1186/1744-8069-6-60] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Accepted: 09/22/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The peptide neurotransmitter N-acetylaspartylglutamate (NAAG) is widely expressed throughout the vertebrate nervous system, including the pain processing neuraxis. Inhibitors of NAAG peptidases are analgesic in animal models of pain. However, the brain regions involved in NAAG's analgesic action have not been rigorously defined. Group II metabotropic glutamate receptors (mGluR2/3) play a role in pain processing in the laterocapsular part of the central nucleus of the amygdala (CeLC). Given the high concentration of NAAG in the amygdala and its activation of group II mGluRs (mGluR3 > mGluR2), this study was undertaken using the mouse formalin model of inflammatory pain to test the hypothesis that NAAG influences pain processing in the amygdala. Evoked excitatory postsynaptic currents (eEPSCs) were studied in neurons in the CeLC of mouse brain slices following stimulation of the spinoparabrachial amygdaloid afferents. RESULTS Application of a NAAG peptidase inhibitor, ZJ43, dose dependently inhibited the amplitude of the eEPSCs by up to 50% in control CeLC demonstrating the role of NAAG in regulation of excitatory transmission at this synapse. A group II mGluR agonist (SLx-3095-1) similarly inhibited eEPSC amplitude by about 30%. Both effects were blocked by the group II mGluR antagonist LY341495. ZJ43 was much less effective than SLx in reducing eEPSCs 24 hours post inflammation suggesting an inflammation induced reduction in NAAG release or an increase in the ratio of mGluR2 to mGluR3 expression. Systemic injection of ZJ43 proximal to the time of inflammation blocked peripheral inflammation-induced increases in synaptic transmission of this pathway 24 hrs later and blocked the induction of mechanical allodynia that developed by this time point. CONCLUSIONS The main finding of this study is that NAAG and NAAG peptidase inhibition reduce excitatory neurotransmission and inflammation-induced plasticity at the spinoparabrachial synapse within the pain processing pathway of the central amygdaloid nucleus.
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Affiliation(s)
- Mary O Adedoyin
- Department of Biology, Georgetown University, Biology Reiss Building 37th and O St. NW, Washington, D.C. 20057, USA
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Soussi R, Zhang N, Tahtakran S, Houser CR, Esclapez M. Heterogeneity of the supramammillary-hippocampal pathways: evidence for a unique GABAergic neurotransmitter phenotype and regional differences. Eur J Neurosci 2010; 32:771-85. [PMID: 20722723 PMCID: PMC2974797 DOI: 10.1111/j.1460-9568.2010.07329.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The supramammillary nucleus (SuM) provides substantial projections to the hippocampal formation. This hypothalamic structure is involved in the regulation of hippocampal theta rhythm and therefore the control of hippocampal-dependent cognitive functions as well as emotional behavior. A major goal of this study was to characterize the neurotransmitter identity of the SuM-hippocampal pathways. Our findings demonstrate two distinct neurochemical pathways in rat. The first pathway originates from neurons in the lateral region of the SuM and innervates the supragranular layer of the dorsal dentate gyrus and, to a much lesser extent, the ventral dentate gyrus. This pathway displays a unique dual phenotype for GABAergic and glutamatergic neurotransmission. Axon terminals contain markers of GABAergic neurotransmission, including the synthesizing enzyme of GABA, glutamate decarboxylase 65, and the vesicular GABA transporter and also a marker of glutamatergic neurotransmission, the vesicular glutamate transporter 2. The second pathway originates from neurons in the most posterior and medial part of the SuM and innervates exclusively the inner molecular layer of the ventral dentate gyrus and the CA2/CA3a pyramidal cell layer of the hippocampus. The axon terminals from the medial part of the SuM contain the vesicular glutamate transporter 2 only. These data demonstrate for the first time the heterogeneity of the SuM-hippocampal pathways, not only from an anatomical but also a neurochemical point of view. These pathways, implicated in different neuronal networks, could modulate different hippocampal activities. They are likely to be involved differently in the regulation of hippocampal theta rhythm and associated cognitive functions as well as emotional behavior.
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Affiliation(s)
- Rabia Soussi
- Inserm, U751, Laboratoire Epilepsie et Cognition, Faculté de Médecine Timone, Marseille, F-13005 France
- Aix-Marseille University, Faculté de Médecine Timone, Marseille, F-13005 France
| | - Nianhui Zhang
- Department of Neurobiology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California 90095
| | - Siroun Tahtakran
- Department of Neurobiology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California 90095
| | - Carolyn R Houser
- Department of Neurobiology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California 90095
- Brain Research Institute, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California 90095
- Research Service, Veterans Affairs Greater Los Angeles Healthcare System, West Los Angeles, Los Angeles, California 90073
| | - Monique Esclapez
- Inserm, U751, Laboratoire Epilepsie et Cognition, Faculté de Médecine Timone, Marseille, F-13005 France
- Aix-Marseille University, Faculté de Médecine Timone, Marseille, F-13005 France
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Kaufling J, Veinante P, Pawlowski SA, Freund-Mercier MJ, Barrot M. gamma-Aminobutyric acid cells with cocaine-induced DeltaFosB in the ventral tegmental area innervate mesolimbic neurons. Biol Psychiatry 2010; 67:88-92. [PMID: 19748079 DOI: 10.1016/j.biopsych.2009.08.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 07/10/2009] [Accepted: 08/02/2009] [Indexed: 11/27/2022]
Abstract
BACKGROUND The transcription factor DeltaFosB is implicated in the plasticity induced by drugs of abuse. We showed that psychostimulants induce DeltaFosB in gamma-aminobutyric acid (GABA) cells of a caudal subregion of the ventral tegmental area (VTA) that was named tail of the VTA (tVTA). Although tVTA mostly shares VTA inputs, its outputs remain to be characterized. METHODS The tVTA efferents were studied by iontophoretic injections of the anterograde tracer biotinylated dextran amine (BDA). To further study VTA inputs arising from tVTA, injections of the retrograde tracer Fluoro-Gold were combined with multiple labeling by immunohistochemistry in rats treated with cocaine. Indirect projections from the tVTA to the nucleus accumbens were assessed with a double-tracing approach, cholera toxin B subunit (CTB) being delivered in the nucleus accumbens and BDA in the tVTA. RESULTS Tract-tracing studies showed that tVTA heavily projects to the midbrain dopaminergic system and revealed terminal appositions with dopamine cells in the VTA. Double-labeling studies demonstrated that this tVTA output is mostly GABAergic, includes cells in which cocaine exposure induces DeltaFosB, and displays appositions to dopamine cells projecting to the nucleus accumbens. CONCLUSIONS The GABA neurons expressing DeltaFosB in the tVTA after cocaine exposure project to the dopamine mesolimbic neurons.
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Affiliation(s)
- Jennifer Kaufling
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Strasbourg, France
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Simon MJ, Molina F, Puerto A. Conditioned place preference but not rewarding self-stimulation after electrical activation of the external lateral parabrachial nucleus. Behav Brain Res 2009; 205:443-9. [DOI: 10.1016/j.bbr.2009.07.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2009] [Revised: 07/21/2009] [Accepted: 07/26/2009] [Indexed: 11/27/2022]
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Kaufling J, Veinante P, Pawlowski SA, Freund-Mercier MJ, Barrot M. Afferents to the GABAergic tail of the ventral tegmental area in the rat. J Comp Neurol 2009; 513:597-621. [PMID: 19235223 DOI: 10.1002/cne.21983] [Citation(s) in RCA: 243] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We previously showed that chronic psychostimulant exposure induces the transcription factor DeltaFosB in gamma-aminobutyric acid (GABA)ergic neurons of the caudal tier of the ventral tegmental area (VTA). This subregion was defined as the tail of the VTA (tVTA). In the present study, we showed that tVTA can also be visualized by analyzing FosB/DeltaFosB response following acute cocaine injection. This induction occurs in GABAergic neurons, as identified by glutamic acid decarboxylase (GAD) expression. To characterize tVTA further, we mapped its inputs by using the retrograde tracers Fluoro-Gold or cholera toxin B subunit. Retrogradely labeled neurons were observed in the medial prefrontal cortex, the lateral septum, the ventral pallidum, the bed nucleus of the stria terminalis, the substantia innominata, the medial and lateral preoptic areas, the lateral and dorsal hypothalamic areas, the lateral habenula, the intermediate layers of the superior colliculus, the dorsal raphe, the periaqueductal gray, and the mesencephalic and pontine reticular formation. Projections from the prefrontal cortex, the hypothalamus, and the lateral habenula to the tVTA were also shown by using the anterograde tracer biotinylated dextran amine (BDA). We showed that the central nucleus of the amygdala innervates the anterior extent of the VTA but not the tVTA. Moreover, the tVTA mainly receives non-aminergic inputs from the dorsal raphe and the locus coeruleus. Although the tVTA has a low density of dopaminergic neurons, its afferents are mostly similar to those targeting the rest of the VTA. This suggests that the tVTA can be considered as a VTA subregion despite its caudal location.
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Affiliation(s)
- Jennifer Kaufling
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique and Université de Strasbourg, France
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Takahashi Y, Ikeda R, Kato F. Synaptic potentiation in the central amygdala involves different mechanisms depending on pain model . ACTA ACUST UNITED AC 2009. [DOI: 10.11154/pain.24.137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yukari Takahashi
- Laboratory of Neurophysiology, Department of Neuroscience, Jikei University School of Medicine
| | - Ryo Ikeda
- Department of Orthopedics, Jikei University School of Medicine
| | - Fusao Kato
- Laboratory of Neurophysiology, Department of Neuroscience, Jikei University School of Medicine
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Justice NJ, Yuan ZF, Sawchenko PE, Vale W. Type 1 corticotropin-releasing factor receptor expression reported in BAC transgenic mice: implications for reconciling ligand-receptor mismatch in the central corticotropin-releasing factor system. J Comp Neurol 2008; 511:479-96. [PMID: 18853426 DOI: 10.1002/cne.21848] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In addition to its established role in initiating the endocrine arm of the stress response, corticotropin-releasing factor (CRF) can act in the brain to modulate neural pathways that effect coordinated physiological and behavioral adjustments to stress. Although CRF is expressed in a set of interconnected limbic and autonomic cell groups implicated as primary sites of stress-related peptide action, most of these are lacking or impoverished in CRF receptor (CRFR) expression. Understanding the distribution of functional receptor expression has been hindered by the low resolution of ligand binding approaches and the lack of specific antisera, which have supported immunolocalizations at odds with analyses at the mRNA level. We have generated a transgenic mouse that shows expression of the principal, or type 1, CRFR (CRFR1). This mouse expresses GFP in a cellular distribution that largely mimics that of CRFR1 mRNA and is extensively colocalized with it in individual neurons. GFP-labeled cells display indices of activation (Fos induction) in response to central CRF injection. At the cellular level, GFP labeling marks somatic and proximal dendritic morphology with high resolution and is also localized to axonal projections of at least some labeled cell groups. This includes a presence in synaptic inputs to central autonomic structures such as the central amygdalar nucleus, which is implicated as a stress-related site of CRF action, but lacks cellular CRFR1 expression. These findings validate a new tool for pursuing the role of central CRFR signaling in stress adaptation and suggest means by which the pervasive ligand-receptor mismatch in this system may be reconciled.
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Affiliation(s)
- Nicholas J Justice
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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Abstract
Glutamatergic projections from the parabrachial nucleus to the central amygdala are implicated in pain transmission. In this issue of Neuron, Delaney et al. identify a new form of adrenergic modulation at these synapses, demonstrating that noradrenaline-induced suppression of glutamate release is mediated by a decrease in the number of sites of synaptic transmission without changes in probability of release.
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Delaney AJ, Crane JW, Sah P. Noradrenaline modulates transmission at a central synapse by a presynaptic mechanism. Neuron 2008; 56:880-92. [PMID: 18054863 DOI: 10.1016/j.neuron.2007.10.022] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 09/14/2007] [Accepted: 10/09/2007] [Indexed: 10/22/2022]
Abstract
The lateral division of the central amygdala (CeAL) is the target of ascending fibers from the pain-responsive and stress-responsive nuclei in the brainstem. We show that single fiber inputs from the nociceptive pontine parabrachial nucleus onto CeAL neurons form suprathreshold glutamatergic synapses with multiple release sites. Noradrenaline, acting at presynaptic alpha2 receptors, potently inhibits this synapse. This inhibition results from a decrease in the number of active release sites with no change in release probability. Introduction of a presynaptic scavenger of Gbetagamma subunits blocked the effects of noradrenaline, and botulinum toxin A reduced its effects, showing a direct action of betagamma subunits on the release machinery. These data illustrate a mechanism of presynaptic modulation where the output of a large multiple-release-site synapse is potently regulated by endogenously released noradrenaline and suggests that the CeA may be a target for the central nociceptive actions of noradrenaline.
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Affiliation(s)
- Andrew J Delaney
- The Queensland Brain Institute, The University of Queensland, QLD 4072 Australia
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D'Hanis W, Linke R, Yilmazer-Hanke DM. Topography of thalamic and parabrachial calcitonin gene-related peptide (CGRP) immunoreactive neurons projecting to subnuclei of the amygdala and extended amygdala. J Comp Neurol 2007; 505:268-91. [PMID: 17879271 DOI: 10.1002/cne.21495] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Injections of calcitonin gene-related peptide (CGRP) into the amygdala evoke fear-related behaviors and antinociceptive effects. In the present study we therefore characterized CGRP-containing amygdaloid afferents by injecting the retrograde tracer FluoroGold (FG) into subnuclei of the amygdala and adjacent divisions of the extended amygdala, namely, the lateral (LA) and central (CE) amygdaloid nuclei, interstitial nucleus of the posterior limb of the anterior commissure (IPAC), and the amygdalostriatal area (AStr). The distribution of retrogradely FG-labeled neurons and colocalization of CGRP-immunoreactivity with FG-labeling were mapped in the posterior paralaminar thalamic complex and parabrachial nuclei. The analysis of the posterior thalamus revealed that about 50% of CGRP-containing neurons projected to the AStr, the projections originating in the medial part of the medial geniculate body, posterior intralaminar nucleus, parvicellular subparafascicular nucleus, and peripeduncular nucleus. However, the percentage of CGRP-containing thalamic neurons projecting to the adjacent LA, medial part of the CE, and ventrocaudal part of the caudatoputamen rapidly dropped to 3-9%. There were no double-labeled cells after injections into the lateral and capsular parts of the CE and the IPAC. Thus, the AStr received the heaviest CGRP-containing projection from the posterior thalamus. CGRP-containing parabrachial neurons projected to the AStr and lateral, capsular, and medial parts of the CE, the projections originating in the external, crescent, and central parts of the lateral parabrachial nucleus and external part of the medial parabrachial nucleus. The results demonstrate a distinct projection pattern of CGRP-containing thalamic and parabrachial neurons to subnuclei of the amygdala and extended amygdala.
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Affiliation(s)
- W D'Hanis
- Institute of Anatomy, Medical Faculty, Otto-von-Guericke University, D-39120 Magdeburg, Germany
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