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Cheung KYM, Nair A, Li LY, Shapiro MG, Anderson DJ. Population coding of predator imminence in the hypothalamus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.12.607651. [PMID: 39211163 PMCID: PMC11360964 DOI: 10.1101/2024.08.12.607651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Hypothalamic VMHdm SF1 neurons are activated by predator cues and are necessary and sufficient for instinctive defensive responses. However, such data do not distinguish which features of a predator encounter are encoded by VMHdm SF1 neural activity. To address this issue, we imaged VMHdm SF1 neurons at single-cell resolution in freely behaving mice exposed to a natural predator in varying contexts. Our results reveal that VMHdm SF1 neurons do not represent different defensive behaviors, but rather encode predator identity and multiple predator-evoked internal states, including threat-evoked fear/anxiety; neophobia or arousal; predator imminence; and safety. Notably, threat and safety are encoded bi-directionally by anti-correlated subpopulations. Finally, individual differences in predator defensiveness are correlated with differences in VMHdm SF1 response dynamics. Thus, different threat-related internal state variables are encoded by distinct neuronal subpopulations within a genetically defined, anatomically restricted hypothalamic cell class. Highlights Distinct subsets of VMHdm SF1 neurons encode multiple predator-evoked internal states. Anti-correlated subsets encode safety vs. threat in a bi-directional mannerA population code for predator imminence is identified using a novel assay VMHdm SF1 dynamics correlate with individual variation in predator defensiveness.
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2
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Amygdala Intercalated Cells: Gate Keepers and Conveyors of Internal State to the Circuits of Emotion. J Neurosci 2022; 42:9098-9109. [PMID: 36639901 PMCID: PMC9761677 DOI: 10.1523/jneurosci.1176-22.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/19/2022] [Accepted: 10/16/2022] [Indexed: 01/09/2023] Open
Abstract
Generating adaptive behavioral responses to emotionally salient stimuli requires evaluation of complex associations between multiple sensations, the surrounding context, and current internal state. Neural circuits within the amygdala parse this emotional information, undergo synaptic plasticity to reflect learned associations, and evoke appropriate responses through their projections to the brain regions orchestrating these behaviors. Information flow within the amygdala is regulated by the intercalated cells (ITCs), which are densely packed clusters of GABAergic neurons that encircle the basolateral amygdala (BLA) and provide contextually relevant feedforward inhibition of amygdala nuclei, including the central and BLA. Emerging studies have begun to delineate the unique contribution of each ITC cluster and establish ITCs as key loci of plasticity in emotional learning. In this review, we summarize the known connectivity and function of individual ITC clusters and explore how different neuromodulators conveying internal state act via ITC gates to shape emotionally motivated behavior. We propose that the behavioral state-dependent function of ITCs, their unique genetic profile, and rich expression of neuromodulator receptors make them potential therapeutic targets for disorders, such as anxiety, schizophrenia spectrum, and addiction.
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3
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Zafiri D, Duvarci S. Dopaminergic circuits underlying associative aversive learning. Front Behav Neurosci 2022; 16:1041929. [PMID: 36439963 PMCID: PMC9685162 DOI: 10.3389/fnbeh.2022.1041929] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/25/2022] [Indexed: 11/12/2022] Open
Abstract
Associative aversive learning enables animals to predict and avoid threats and thus is critical for survival and adaptive behavior. Anxiety disorders are characterized with deficits in normal aversive learning mechanisms and hence understanding the neural circuits underlying aversive learning and memory has high clinical relevance. Recent studies have revealed the dopamine system as one of the key modulators of aversive learning. In this review, we highlight recent advances that provide insights into how distinct dopaminergic circuits contribute to aversive learning and memory.
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4
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Baldi E, Costa A, Rani B, Passani MB, Blandina P, Romano A, Provensi G. Oxytocin and Fear Memory Extinction: Possible Implications for the Therapy of Fear Disorders? Int J Mol Sci 2021; 22:10000. [PMID: 34576161 PMCID: PMC8467761 DOI: 10.3390/ijms221810000] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/07/2021] [Accepted: 09/10/2021] [Indexed: 02/07/2023] Open
Abstract
Several psychiatric conditions such as phobias, generalized anxiety, and post-traumatic stress disorder (PTSD) are characterized by pathological fear and anxiety. The main therapeutic approach used in the management of these disorders is exposure-based therapy, which is conceptually based upon fear extinction with the formation of a new safe memory association, allowing the reduction in behavioral conditioned fear responses. Nevertheless, this approach is only partially resolutive, since many patients have difficulty following the demanding and long process, and relapses are frequently observed over time. One strategy to improve the efficacy of the cognitive therapy is the combination with pharmacological agents. Therefore, the identification of compounds able to strengthen the formation and persistence of the inhibitory associations is a key goal. Recently, growing interest has been aroused by the neuropeptide oxytocin (OXT), which has been shown to have anxiolytic effects. Furthermore, OXT receptors and binding sites have been found in the critical brain structures involved in fear extinction. In this review, the recent literature addressing the complex effects of OXT on fear extinction at preclinical and clinical levels is discussed. These studies suggest that the OXT roles in fear behavior are due to its local effects in several brain regions, most notably, distinct amygdaloid regions.
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Affiliation(s)
- Elisabetta Baldi
- Section of Physiological Sciences, Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy;
| | - Alessia Costa
- Section of Clinical Pharmacology and Oncology, Department of Health Sciences (DSS), University of Florence, 50139 Florence, Italy; (A.C.); (B.R.); (M.B.P.)
| | - Barbara Rani
- Section of Clinical Pharmacology and Oncology, Department of Health Sciences (DSS), University of Florence, 50139 Florence, Italy; (A.C.); (B.R.); (M.B.P.)
| | - Maria Beatrice Passani
- Section of Clinical Pharmacology and Oncology, Department of Health Sciences (DSS), University of Florence, 50139 Florence, Italy; (A.C.); (B.R.); (M.B.P.)
| | - Patrizio Blandina
- Section of Pharmacology of Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, 50139 Florence, Italy;
| | - Adele Romano
- Department of Physiology and Pharmacology ‘V. Erspamer’, Sapienza University of Rome, 00185 Rome, Italy;
| | - Gustavo Provensi
- Section of Pharmacology of Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, 50139 Florence, Italy;
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5
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Asede D, Okoh J, Ali S, Doddapaneni D, Bolton MM. Deletion of ErbB4 Disrupts Synaptic Transmission and Long-Term Potentiation of Thalamic Input to Amygdalar Medial Paracapsular Intercalated Cells. Front Synaptic Neurosci 2021; 13:697110. [PMID: 34393751 PMCID: PMC8355744 DOI: 10.3389/fnsyn.2021.697110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 07/08/2021] [Indexed: 11/20/2022] Open
Abstract
Identification of candidate risk genes and alteration in the expression of proteins involved in regulating inhibitory neuron function in various psychiatric disorders, support the notion that GABAergic neuron dysfunction plays an important role in disease etiology. Genetic variations in neuregulin and its receptor kinase ErbB4, expressed exclusively by GABAergic neurons in the CNS, have been linked with schizophrenia. In the amygdala, ErbB4 is highly expressed in GABAergic intercalated cell clusters (ITCs), which play a critical role in amygdala-dependent behaviors. It is however unknown whether ErbB4 deletion from ITCs affects their synaptic properties and function in amygdala circuitry. Here, we examined the impact of ErbB4 deletion on inhibitory and excitatory circuits recruiting medial paracapsular ITCs (mpITCs) using electrophysiological techniques. Ablation of ErbB4 in mpITCs suppressed NMDA receptor-mediated synaptic transmission at thalamo-mpITC synapses and enhanced thalamic driven GABAergic transmission onto mpITCs. Furthermore, long-term potentiation (LTP) at thalamo-mpITC synapses was compromised in ErbB4 mutant mice, indicating that ErbB4 activity is critical for LTP at these synapses. Together, our findings suggest that ErbB4 deletion from mpITCs disrupts excitation-inhibition balance and learning mechanisms in amygdala circuits.
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Affiliation(s)
- Douglas Asede
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
| | - James Okoh
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
| | - Sabah Ali
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
| | - Divyesh Doddapaneni
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
| | - M McLean Bolton
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
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6
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Seewald A, Schönherr S, Hörtnagl H, Ehrlich I, Schmuckermair C, Ferraguti F. Fear Memory Retrieval Is Associated With a Reduction in AMPA Receptor Density at Thalamic to Amygdala Intercalated Cell Synapses. Front Synaptic Neurosci 2021; 13:634558. [PMID: 34295235 PMCID: PMC8290482 DOI: 10.3389/fnsyn.2021.634558] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 06/14/2021] [Indexed: 12/12/2022] Open
Abstract
The amygdala plays a crucial role in attaching emotional significance to environmental cues. Its intercalated cell masses (ITC) are tight clusters of GABAergic neurons, which are distributed around the basolateral amygdala complex. Distinct ITC clusters are involved in the acquisition and extinction of conditioned fear responses. Previously, we have shown that fear memory retrieval reduces the AMPA/NMDA ratio at thalamic afferents to ITC neurons within the dorsal medio-paracapsular cluster. Here, we investigate the molecular mechanisms underlying the fear-mediated reduction in the AMPA/NMDA ratio at these synapses and, in particular, whether specific changes in the synaptic density of AMPA receptors underlie the observed change. To this aim, we used a detergent-digested freeze-fracture replica immunolabeling technique (FRIL) approach that enables to visualize the spatial distribution of intrasynaptic AMPA receptors at high resolution. AMPA receptors were detected using an antibody raised against an epitope common to all AMPA subunits. To visualize thalamic inputs, we virally transduced the posterior thalamic complex with Channelrhodopsin 2-YFP, which is anterogradely transported along axons. Using face-matched replica, we confirmed that the postsynaptic elements were ITC neurons due to their prominent expression of μ-opioid receptors. With this approach, we show that, following auditory fear conditioning in mice, the formation and retrieval of fear memory is linked to a significant reduction in the density of AMPA receptors, particularly at spine synapses formed by inputs of the posterior intralaminar thalamic and medial geniculate nuclei onto identified ITC neurons. Our study is one of the few that has directly linked the regulation of AMPA receptor trafficking to memory processes in identified neuronal networks, by showing that fear-memory induced reduction in AMPA/NMDA ratio at thalamic-ITC synapses is associated with a reduced postsynaptic AMPA receptor density.
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Affiliation(s)
- Anna Seewald
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Sabine Schönherr
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Heide Hörtnagl
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Ingrid Ehrlich
- Center for Integrative Neuroscience, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Department of Neurobiology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany
| | | | - Francesco Ferraguti
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
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7
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Hájos N. Interneuron Types and Their Circuits in the Basolateral Amygdala. Front Neural Circuits 2021; 15:687257. [PMID: 34177472 PMCID: PMC8222668 DOI: 10.3389/fncir.2021.687257] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/11/2021] [Indexed: 11/29/2022] Open
Abstract
The basolateral amygdala (BLA) is a cortical structure based on its cell types, connectivity features, and developmental characteristics. This part of the amygdala is considered to be the main entry site of processed and multisensory information delivered via cortical and thalamic afferents. Although GABAergic inhibitory cells in the BLA comprise only 20% of the entire neuronal population, they provide essential control over proper network operation. Previous studies have uncovered that GABAergic cells in the basolateral amygdala are as diverse as those present in other cortical regions, including the hippocampus and neocortex. To understand the role of inhibitory cells in various amygdala functions, we need to reveal the connectivity and input-output features of the different types of GABAergic cells. Here, I review the recent achievements in uncovering the diversity of GABAergic cells in the basolateral amygdala with a specific focus on the microcircuit organization of these inhibitory cells.
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Affiliation(s)
- Norbert Hájos
- Laboratory of Network Neurophysiology, ELRN Institute of Experimental Medicine, Budapest, Hungary
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8
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Hagihara KM, Bukalo O, Zeller M, Aksoy-Aksel A, Karalis N, Limoges A, Rigg T, Campbell T, Mendez A, Weinholtz C, Mahn M, Zweifel LS, Palmiter RD, Ehrlich I, Lüthi A, Holmes A. Intercalated amygdala clusters orchestrate a switch in fear state. Nature 2021; 594:403-407. [PMID: 34040259 DOI: 10.1038/s41586-021-03593-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 04/28/2021] [Indexed: 12/14/2022]
Abstract
Adaptive behaviour necessitates the formation of memories for fearful events, but also that these memories can be extinguished. Effective extinction prevents excessive and persistent reactions to perceived threat, as can occur in anxiety and 'trauma- and stressor-related' disorders1. However, although there is evidence that fear learning and extinction are mediated by distinct neural circuits, the nature of the interaction between these circuits remains poorly understood2-6. Here, through a combination of in vivo calcium imaging, functional manipulations, and slice physiology, we show that distinct inhibitory clusters of intercalated neurons (ITCs) in the mouse amygdala exert diametrically opposed roles during the acquisition and retrieval of fear extinction memory. Furthermore, we find that the ITC clusters antagonize one another through mutual synaptic inhibition and differentially access functionally distinct cortical- and midbrain-projecting amygdala output pathways. Our findings show that the balance of activity between ITC clusters represents a unique regulatory motif that orchestrates a distributed neural circuitry, which in turn regulates the switch between high- and low-fear states. These findings suggest that the ITCs have a broader role in a range of amygdala functions and associated brain states that underpins the capacity to adapt to salient environmental demands.
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Affiliation(s)
- Kenta M Hagihara
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Olena Bukalo
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Martin Zeller
- Hertie Institute for Clinical Brain Research, Tübingen, Germany.,Centre for Integrative Neuroscience, Tübingen, Germany
| | - Ayla Aksoy-Aksel
- Hertie Institute for Clinical Brain Research, Tübingen, Germany.,Centre for Integrative Neuroscience, Tübingen, Germany.,Department of Neurobiology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany
| | - Nikolaos Karalis
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Aaron Limoges
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Tanner Rigg
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Tiffany Campbell
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Adriana Mendez
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Chase Weinholtz
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Mathias Mahn
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Larry S Zweifel
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA.,Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Richard D Palmiter
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.,Department of Biochemistry, University of Washington, Seattle, WA, USA.,Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Ingrid Ehrlich
- Hertie Institute for Clinical Brain Research, Tübingen, Germany.,Centre for Integrative Neuroscience, Tübingen, Germany.,Department of Neurobiology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany
| | - Andreas Lüthi
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA.
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9
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Aksoy-Aksel A, Gall A, Seewald A, Ferraguti F, Ehrlich I. Midbrain dopaminergic inputs gate amygdala intercalated cell clusters by distinct and cooperative mechanisms in male mice. eLife 2021; 10:e63708. [PMID: 34028352 PMCID: PMC8143799 DOI: 10.7554/elife.63708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 05/06/2021] [Indexed: 01/04/2023] Open
Abstract
Dopaminergic signaling plays an important role in associative learning, including fear and extinction learning. Dopaminergic midbrain neurons encode prediction error-like signals when threats differ from expectations. Within the amygdala, GABAergic intercalated cell (ITC) clusters receive one of the densest dopaminergic projections, but their physiological consequences are incompletely understood. ITCs are important for fear extinction, a function thought to be supported by activation of ventromedial ITCs that inhibit central amygdala fear output. In mice, we reveal two distinct novel mechanisms by which mesencephalic dopaminergic afferents control ITCs. Firstly, they co-release GABA to mediate rapid, direct inhibition. Secondly, dopamine suppresses inhibitory interactions between distinct ITC clusters via presynaptic D1 receptors. Early extinction training augments both GABA co-release onto dorsomedial ITCs and dopamine-mediated suppression of dorso- to ventromedial inhibition between ITC clusters. These findings provide novel insights into dopaminergic mechanisms shaping the activity balance between distinct ITC clusters that could support their opposing roles in fear behavior.
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Affiliation(s)
- Ayla Aksoy-Aksel
- Hertie Institute for Clinical Brain ResearchTübingenGermany
- Centre for Integrative NeuroscienceTübingenGermany
- Department of Neurobiology, Institute of Biomaterials and Biomolecular Systems, University of StuttgartStuttgartGermany
| | - Andrea Gall
- Hertie Institute for Clinical Brain ResearchTübingenGermany
- Centre for Integrative NeuroscienceTübingenGermany
- Department of Neurobiology, Institute of Biomaterials and Biomolecular Systems, University of StuttgartStuttgartGermany
| | - Anna Seewald
- Department of Pharmacology, Medical University of InnsbruckInnsbruckAustria
| | | | - Ingrid Ehrlich
- Hertie Institute for Clinical Brain ResearchTübingenGermany
- Centre for Integrative NeuroscienceTübingenGermany
- Department of Neurobiology, Institute of Biomaterials and Biomolecular Systems, University of StuttgartStuttgartGermany
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10
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Apical intercalated cell cluster: A distinct sensory regulator in the amygdala. Cell Rep 2021; 35:109151. [PMID: 34010641 DOI: 10.1016/j.celrep.2021.109151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 02/20/2021] [Accepted: 04/23/2021] [Indexed: 12/13/2022] Open
Abstract
GABAergic neurons regulate different aspects of information processing in the amygdala. Among these are clusters of intercalated cells (ITCs), which have been implicated in fear-related behaviors. Although a few of the ITC clusters have been studied, the functional role of apical ITCs (apITCs) is unknown. Here, we combine monosynaptic rabies tracing with optogenetics and demonstrate that apITCs receive synaptic input from medial geniculate nucleus (MGm), posterior intralaminar nucleus (PIN), and medial dorsal nucleus of the thalamus and from a diverse range of cortical areas including temporal association, entorhinal, insular, piriform, and somatosensory cortex. Upon fear learning, PIN/MGm inputs are strengthened, indicative of their involvement in fear behaviors. 3-D reconstruction of apITCs reveals local arborization and innervation of the dorsal striatum and lateral amygdala. We further show that apITCs provide sensory feedforward inhibition to LA principal cells, a putative mechanism for controlling plasticity during fear learning.
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11
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Rajbhandari AK, Octeau CJ, Gonzalez S, Pennington ZT, Mohamed F, Trott J, Chavez J, Ngyuen E, Keces N, Hong WZ, Neve RL, Waschek J, Khakh BS, Fanselow MS. A Basomedial Amygdala to Intercalated Cells Microcircuit Expressing PACAP and Its Receptor PAC1 Regulates Contextual Fear. J Neurosci 2021; 41:3446-3461. [PMID: 33637560 PMCID: PMC8051692 DOI: 10.1523/jneurosci.2564-20.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 02/12/2021] [Accepted: 02/17/2021] [Indexed: 11/21/2022] Open
Abstract
Trauma can cause dysfunctional fear regulation leading some people to develop disorders, such as post-traumatic stress disorder (PTSD). The amygdala regulates fear, whereas PACAP (pituitary adenylate activating peptide) and PAC1 receptors are linked to PTSD symptom severity at genetic/epigenetic levels, with a strong link in females with PTSD. We discovered a PACAPergic projection from the basomedial amygdala (BMA) to the medial intercalated cells (mICCs) in adult mice. In vivo optogenetic stimulation of this pathway increased CFOS expression in mICCs, decreased fear recall, and increased fear extinction. Selective deletion of PAC1 receptors from the mICCs in females reduced fear acquisition, but enhanced fear generalization and reduced fear extinction in males. Optogenetic stimulation of the BMA-mICC PACAPergic pathway produced EPSCs in mICC neurons, which were enhanced by the PAC1 receptor antagonist, PACAP 6-38. Our findings show that mICCs modulate contextual fear in a dynamic and sex-dependent manner via a microcircuit containing the BMA and mICCs, and in a manner that was dependent on behavioral state.SIGNIFICANCE STATEMENT Traumatic stress can affect different aspects of fear behaviors, including fear learning, generalization of learned fear to novel contexts, how the fear of the original context is recalled, and how fear is reduced over time. While the amygdala has been studied for its role in regulation of different aspects of fear, the molecular circuitry of this structure is quite complex. In addition, aspects of fear can be modulated differently in males and females. Our findings show that a specific circuitry containing the neuropeptide PACAP and its receptor, PAC1, regulates various aspects of fear, including acquisition, generalization, recall, and extinction in a sexually dimorphic manner, characterizing a novel pathway that modulates traumatic fear.
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Affiliation(s)
- Abha K Rajbhandari
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| | - Christopher J Octeau
- Department of Physiology, University of California, Los Angeles, California 90095
| | - Sarah Gonzalez
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| | - Zachary T Pennington
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Farzanna Mohamed
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Jeremy Trott
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| | - Jasmine Chavez
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Erin Ngyuen
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Natasha Keces
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Weizhe Z Hong
- Department of Neurobiology, University of California, Los Angeles, California 90095
| | - Rachael L Neve
- Gene Delivery Technology Core, Massachusetts General Hospital, Boston, Massachusetts, California 02114
| | - James Waschek
- Department of Psychiatry, University of California, Los Angeles, California 90095
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, California 90095
- Department of Neurobiology, University of California, Los Angeles, California 90095
| | - Michael S Fanselow
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
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12
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Franceschi Biagioni A, Cellot G, Pati E, Lozano N, Ballesteros B, Casani R, Coimbra NC, Kostarelos K, Ballerini L. Graphene oxide prevents lateral amygdala dysfunctional synaptic plasticity and reverts long lasting anxiety behavior in rats. Biomaterials 2021; 271:120749. [PMID: 33714913 DOI: 10.1016/j.biomaterials.2021.120749] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/23/2021] [Accepted: 02/27/2021] [Indexed: 12/19/2022]
Abstract
Engineered small graphene oxide (s-GO) sheets were previously shown to reversibly down-regulate glutamatergic synapses in the hippocampus of juvenile rats, disclosing an unexpected translational potential of these nanomaterials to target selective synapses in vivo. Synapses are anatomical specializations acting in the Central Nervous System (CNS) as functional interfaces among neurons. Dynamic changes in synaptic function, named synaptic plasticity, are crucial to learning and memory. More recently, pathological mechanisms involving dysfunctional synaptic plasticity were implicated in several brain diseases, from dementia to anxiety disorders. Hyper-excitability of glutamatergic neurons in the lateral nucleus of the amygdala complex (LA) is substantially involved in the storage of aversive memory induced by stressful events enabling post-traumatic stress disorder (PTSD). Here we translated in PTSD animal model the ability of s-GO, when stereotaxically administered to hamper LA glutamatergic transmission and to prevent the behavioral response featured in long-term aversive memory. We propose that s-GO, by interference with glutamatergic plasticity, impair LA-dependent memory retrieval related to PTSD.
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Affiliation(s)
- Audrey Franceschi Biagioni
- Neuron Physiology and Technology Lab, International School for Advanced Studies (SISSA), Neuroscience, Via Bonomea 265, 34136, Trieste, Italy
| | - Giada Cellot
- Neuron Physiology and Technology Lab, International School for Advanced Studies (SISSA), Neuroscience, Via Bonomea 265, 34136, Trieste, Italy
| | - Elisa Pati
- Neuron Physiology and Technology Lab, International School for Advanced Studies (SISSA), Neuroscience, Via Bonomea 265, 34136, Trieste, Italy
| | - Neus Lozano
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - Belén Ballesteros
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - Raffaele Casani
- Neuron Physiology and Technology Lab, International School for Advanced Studies (SISSA), Neuroscience, Via Bonomea 265, 34136, Trieste, Italy
| | - Norberto Cysne Coimbra
- Laboratory of Neuroanatomy & Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes 3900, 14049-900, Ribeirão Preto, SP, Brazil
| | - Kostas Kostarelos
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193, Barcelona, Spain; Nanomedicine Lab, National Graphene Institute and Faculty of Biology, Medicine & Health, The University of Manchester, AV Hill Building, Oxford Rd, Manchester, M13 9PL, United Kingdom
| | - Laura Ballerini
- Neuron Physiology and Technology Lab, International School for Advanced Studies (SISSA), Neuroscience, Via Bonomea 265, 34136, Trieste, Italy.
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Salinas-Hernández XI, Duvarci S. Dopamine in Fear Extinction. Front Synaptic Neurosci 2021; 13:635879. [PMID: 33732133 PMCID: PMC7956961 DOI: 10.3389/fnsyn.2021.635879] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/09/2021] [Indexed: 11/30/2022] Open
Abstract
The ability to extinguish fear memories when threats are no longer present is critical for adaptive behavior. Fear extinction represents a new learning process that eventually leads to the formation of extinction memories. Understanding the neural basis of fear extinction has considerable clinical significance as deficits in extinction learning are the hallmark of human anxiety disorders. In recent years, the dopamine (DA) system has emerged as one of the key regulators of fear extinction. In this review article, we highlight recent advances that have demonstrated the crucial role DA plays in mediating different phases of fear extinction. Emerging concepts and outstanding questions for future research are also discussed.
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Affiliation(s)
| | - Sevil Duvarci
- Institute of Neurophysiology, Neuroscience Center, Goethe University, Frankfurt, Germany
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Maturation of amygdala inputs regulate shifts in social and fear behaviors: A substrate for developmental effects of stress. Neurosci Biobehav Rev 2021; 125:11-25. [PMID: 33581221 DOI: 10.1016/j.neubiorev.2021.01.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/26/2021] [Accepted: 01/26/2021] [Indexed: 11/21/2022]
Abstract
Stress can negatively impact brain function and behaviors across the lifespan. However, stressors during adolescence have particularly harmful effects on brain maturation, and on fear and social behaviors that extend beyond adolescence. Throughout development, social behaviors are refined and the ability to suppress fear increases, both of which are dependent on amygdala activity. We review rodent literature focusing on developmental changes in social and fear behaviors, cortico-amygdala circuits underlying these changes, and how this circuitry is altered by stress. We first describe changes in fear and social behaviors from adolescence to adulthood and parallel developmental changes in cortico-amygdala circuitry. We propose a framework in which maturation of cortical inputs to the amygdala promote changes in social drive and fear regulation, and the particularly damaging effects of stress during adolescence may occur through lasting changes in this circuit. This framework may explain why anxiety and social pathologies commonly co-occur, adolescents are especially vulnerable to stressors impacting social and fear behaviors, and predisposed towards psychiatric disorders related to abnormal cortico-amygdala circuits.
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15
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Tan Q, Li S, Niu J, Liu S, Li Y, Lu Y, Wang Z, Xu W, Wei Y, Guo Z. Resting-State Functional Magnetic Resonance Imaging Reveals Overactivation of the Habitual Control Brain System in Tobacco Dependence. Neuropsychiatr Dis Treat 2021; 17:3753-3768. [PMID: 34984003 PMCID: PMC8703225 DOI: 10.2147/ndt.s334403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 11/27/2021] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION We studied the regulatory mechanism of the habitual brain network in tobacco dependence to provide a theoretical basis for the regulation and cessation of tobacco dependence. METHODS We used resting-state functional magnetic resonance imaging (rs-fMRI) to explore the Fractional amplitude of low-frequency fluctuations (fALFF) and functional connectivity (FC) of the habitual brain network in tobacco-dependent subjects and to evaluate the relationship between the FC level and tobacco selection preference behavior. In total, 29 male tobacco-dependent participants and 28 male nonsmoking participants were recruited. rs-fMRI was used to collect blood oxygen level-dependent signals of the participants in the resting and awake states. After rs-fMRI, all subjects completed cigarette/coin selection tasks (task 1 and task 2). RESULTS Compared with the control group, the tobacco dependence group showed increased fractional amplitude values of fALFF in the left posterior cingulate cortex and right parahippocampus. FC in the tobacco-dependent group was increased in the right inferior temporal gyrus, left middle frontal gyrus, left cingulated gyrus, and bilateral superior frontal gyrus, compared with that in the control group. Moreover, the preference selection behavior was associated with the enhancement of FC about parts of the brain regions in the habitual brain network of the tobacco-dependent participants. Thus, habitual network activity was significantly enhanced in tobacco-dependent participants in the resting state. Moreover, a positive correlation was found between the cigarette selection preference of the smokers and certain brain regions related to the habitual network. DISCUSSION This suggests that increased activity of the habitual brain network may be essential in the development of tobacco-dependent behavior.
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Affiliation(s)
- Qiaowen Tan
- Department of Geriatrics, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
| | - Shaoke Li
- Department of Medical Imaging, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
| | - Juan Niu
- Clinical Psychology Department, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
| | - Shien Liu
- Department of Medical Imaging, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
| | - Yaling Li
- Department of Geriatrics, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
| | - Yujie Lu
- Department of Geriatrics, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
| | - Zhihong Wang
- Department of Geriatrics, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
| | - Wanqun Xu
- Department of Geriatrics, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
| | - Yalin Wei
- Department of Geriatrics, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
| | - Zongjun Guo
- Department of Geriatrics, Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, People's Republic of China
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Hulsman AM, Terburg D, Roelofs K, Klumpers F. Roles of the bed nucleus of the stria terminalis and amygdala in fear reactions. HANDBOOK OF CLINICAL NEUROLOGY 2021; 179:419-432. [PMID: 34225979 DOI: 10.1016/b978-0-12-819975-6.00027-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The bed nucleus of the stria terminalis (BNST) plays a critical modulatory role in driving fear responses. Part of the so-called extended amygdala, this region shares many functions and connections with the substantially more investigated amygdala proper. In this chapter, we review contributions of the BNST and amygdala to subjective, behavioral, and physiological aspects of fear. Despite the fact that both regions are together involved in each of these aspects of fear, they appear complimentary in their contributions. Specifically, the basolateral amygdala (BLA), through its connections to sensory and orbitofrontal regions, is ideally poised for fast learning and controlling fear reactions in a variety of situations. The central amygdala (CeA) relies on BLA input and is particularly important for adjusting physiological and behavioral responses under acute threat. In contrast, the BNST may profit from more extensive striatal and dorsomedial prefrontal connections to drive anticipatory responses under more ambiguous conditions that allow more time for planning. Thus current evidence suggests that the BNST is ideally suited to play a critical role responding to distant or ambiguous threats and could thereby facilitate goal-directed defensive action.
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Affiliation(s)
- Anneloes M Hulsman
- Experimental Psychopathology & Treatment, Behavioural Science Institute, Radboud University, Nijmegen, The Netherlands; Affective Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, The Netherlands
| | - David Terburg
- Department of Experimental Psychology, Utrecht University, Utrecht, The Netherlands; Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - Karin Roelofs
- Experimental Psychopathology & Treatment, Behavioural Science Institute, Radboud University, Nijmegen, The Netherlands; Affective Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, The Netherlands
| | - Floris Klumpers
- Experimental Psychopathology & Treatment, Behavioural Science Institute, Radboud University, Nijmegen, The Netherlands; Affective Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, The Netherlands.
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17
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Sizer SE, Parrish BC, McCool BA. Chronic Ethanol Exposure Potentiates Cholinergic Neurotransmission in the Basolateral Amygdala. Neuroscience 2020; 455:165-176. [PMID: 33385490 DOI: 10.1016/j.neuroscience.2020.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 01/10/2023]
Abstract
Chronic intermittent ethanol (CIE) exposure dysregulates glutamatergic and GABAergic neurotransmission, facilitating basolateral amygdala (BLA) pyramidal neuron hyperexcitability and the expression of anxiety during withdrawal. It is unknown whether ethanol-induced alterations in nucleus basalis magnocellularis (NBM) cholinergic projections to the BLA mediate anxiety-related behaviors through direct modulation of GABA and glutamate afferents. Following 10 days of CIE exposure and 24 h of withdrawal, we recorded GABAergic and glutamatergic synaptic responses in BLA pyramidal neurons with electrophysiology, assessed total protein expression of cholinergic markers, and quantified acetylcholine and choline concentrations using a colorimetric assay. We measured α7 nicotinic acetylcholine receptor (nAChR) dependent modulation of presynaptic function at distinct inputs in AIR- and CIE-exposed BLA coronal slices as a functional read-out of cholinergic neurotransmission. CIE/withdrawal upregulates the endogenous activity of α7 nAChRs, facilitating release at both GABAergic' local' interneuron and glutamatergic synaptic responses to stria terminalis (ST) stimulation, with no effect at GABAergic lateral paracapsular cells (LPCs). CIE caused a three-fold increase in BLA acetylcholine concentration, with no changes in α7 nAChR or cholinergic marker expression. These data illustrate that α7 nAChR-dependent changes in presynaptic function serve as a proxy for CIE-dependent alterations in synaptic acetylcholine levels. Thus, cholinergic projections appear to mediate CIE-induced alterations at GABA/glutamate inputs.
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Affiliation(s)
- Sarah E Sizer
- Department of Physiology and Pharmacology, Piedmont Triad Community Research Center (PTCRC), Wake Forest School of Medicine, 115 S Chestnut Street, Winston-Salem, NC 27101, USA.
| | - Brian C Parrish
- Department of Physiology and Pharmacology, Piedmont Triad Community Research Center (PTCRC), Wake Forest School of Medicine, 115 S Chestnut Street, Winston-Salem, NC 27101, USA.
| | - Brian A McCool
- Department of Physiology and Pharmacology, Piedmont Triad Community Research Center (PTCRC), Wake Forest School of Medicine, 115 S Chestnut Street, Winston-Salem, NC 27101, USA.
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18
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Associative and plastic thalamic signaling to the lateral amygdala controls fear behavior. Nat Neurosci 2020; 23:625-637. [PMID: 32284608 DOI: 10.1038/s41593-020-0620-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 03/05/2020] [Indexed: 01/21/2023]
Abstract
Decades of research support the idea that associations between a conditioned stimulus (CS) and an unconditioned stimulus (US) are encoded in the lateral amygdala (LA) during fear learning. However, direct proof for the sources of CS and US information is lacking. Definitive evidence of the LA as the primary site for cue association is also missing. Here, we show that calretinin (Calr)-expressing neurons of the lateral thalamus (Calr+LT neurons) convey the association of fast CS (tone) and US (foot shock) signals upstream from the LA in mice. Calr+LT input shapes a short-latency sensory-evoked activation pattern of the amygdala via both feedforward excitation and inhibition. Optogenetic silencing of Calr+LT input to the LA prevents auditory fear conditioning. Notably, fear conditioning drives plasticity in Calr+LT neurons, which is required for appropriate cue and contextual fear memory retrieval. Collectively, our results demonstrate that Calr+LT neurons provide integrated CS-US representations to the LA that support the formation of aversive memories.
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19
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Skórzewska A, Lehner M, Wisłowska-Stanek A, Turzyńska D, Sobolewska A, Krząścik P, Szyndler J, Maciejak P, Chmielewska N, Kołosowska K, Płaźnik A. Individual susceptibility or resistance to posttraumatic stress disorder-like behaviours. Behav Brain Res 2020; 386:112591. [PMID: 32194190 DOI: 10.1016/j.bbr.2020.112591] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/19/2020] [Accepted: 02/19/2020] [Indexed: 12/20/2022]
Abstract
The aim of this study was to explore the neurobiological background of individual susceptibility and resistance to the development of posttraumatic stress disorder (PTSD)-like behaviours. Rats were divided into susceptible, PTSD(+), and resistant, PTSD(-), groups based on freezing duration during exposure to aversive context and the time spent in the central area in open field test one week after threefold stress experience (modified single prolonged stress). PTSD(-) rats showed increased concentrations of corticosterone in plasma and changes in GAD67 expression: decreased in the infralimbic cortex (IL) and increased in the lateral amygdala (LA), dentate gyrus (DG), and CA1 area of the hippocampus. Moreover, in this group, we found an increase in the number of CRF-positive nuclei in the parvocellular neurons of the paraventricular hypothalamic nucleus (pPVN). The PTSD(+) group, compared to PTSD(-) rats, had decreased concentrations of corticosterone in plasma and reduced CRF expression in the pPVN, higher CRF expression in the CA1, increased expression of CRF-positive nuclei and GR receptors in the CA3 area of the hippocampus, and increased expression of GR receptors in the DG and the central amygdala (CeA). Biochemical analysis showed higher concentrations of noradrenaline, glutamic acid in the dorsal hippocampus and amygdala and lower levels of dopamine and its metabolites in the amygdala of the PTSD(+) group than in the PTSD(-) group. The study revealed different behavioural and biochemical profiles of PTSD(+) and PTSD(-) rats and suggested that individual differences in hypothalamic-pituitary-adrenal (HPA) axis activity may determine hippocampal- and amygdala-dependent memory and fear processing.
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Affiliation(s)
- Anna Skórzewska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957, Warsaw, Poland.
| | - Małgorzata Lehner
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957, Warsaw, Poland
| | - Aleksandra Wisłowska-Stanek
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, 1B Banacha Street, 02-097, Warsaw, Poland
| | - Danuta Turzyńska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957, Warsaw, Poland
| | - Alicja Sobolewska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957, Warsaw, Poland
| | - Paweł Krząścik
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, 1B Banacha Street, 02-097, Warsaw, Poland
| | - Janusz Szyndler
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, 1B Banacha Street, 02-097, Warsaw, Poland
| | - Piotr Maciejak
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957, Warsaw, Poland; Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, 1B Banacha Street, 02-097, Warsaw, Poland
| | - Natalia Chmielewska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957, Warsaw, Poland
| | - Karolina Kołosowska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957, Warsaw, Poland
| | - Adam Płaźnik
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957, Warsaw, Poland
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20
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Comeras LB, Herzog H, Tasan RO. Neuropeptides at the crossroad of fear and hunger: a special focus on neuropeptide Y. Ann N Y Acad Sci 2019; 1455:59-80. [PMID: 31271235 PMCID: PMC6899945 DOI: 10.1111/nyas.14179] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/15/2019] [Accepted: 06/03/2019] [Indexed: 12/11/2022]
Abstract
Survival in a natural environment forces an individual into constantly adapting purposive behavior. Specified interoceptive neurons monitor metabolic and physiological balance and activate dedicated brain circuits to satisfy essential needs, such as hunger, thirst, thermoregulation, fear, or anxiety. Neuropeptides are multifaceted, central components within such life‐sustaining programs. For instance, nutritional depletion results in a drop in glucose levels, release of hormones, and activation of hypothalamic and brainstem neurons. These neurons, in turn, release several neuropeptides that increase food‐seeking behavior and promote food intake. Similarly, internal and external threats activate neuronal pathways of avoidance and defensive behavior. Interestingly, specific nuclei of the hypothalamus and extended amygdala are activated by both hunger and fear. Here, we introduce the relevant neuropeptides and describe their function in feeding and emotional‐affective behaviors. We further highlight specific pathways and microcircuits, where neuropeptides may interact to identify prevailing homeostatic needs and direct respective compensatory behaviors. A specific focus will be on neuropeptide Y, since it is known for its pivotal role in metabolic and emotional pathways. We hypothesize that the orexigenic and anorexigenic properties of specific neuropeptides are related to their ability to inhibit fear and anxiety.
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Affiliation(s)
- Lucas B Comeras
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| | - Herbert Herzog
- Neuroscience Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Ramon O Tasan
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
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21
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Minami S, Kiyokawa Y, Takeuchi Y. The lateral intercalated cell mass of the amygdala is activated during social buffering of conditioned fear responses in male rats. Behav Brain Res 2019; 372:112065. [PMID: 31260719 DOI: 10.1016/j.bbr.2019.112065] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/21/2019] [Accepted: 06/27/2019] [Indexed: 01/01/2023]
Abstract
The presence of an affiliative conspecific reduces stress responses to a wide variety of stimuli. This phenomenon is termed "social buffering". We previously found that the presence of another Wistar rat (associate) suppressed activation of the lateral amygdala (LA) and ameliorated stress responses to an auditory conditioned stimulus (CS) in a fear-conditioned Wistar subject rat. Subsequent analyses suggested that activation of the posterior complex of the anterior olfactory nucleus (AOP) is responsible for the suppression of the LA. However, it remains unclear how the AOP suppresses the LA. To clarify this issue, a fear-conditioned Wistar subject was exposed to the CS either alone or with a Wistar associate. We also prepared a fear-conditioned Wistar subject that was tested with a Fischer344 (F344) associate as an additional control because F344 associates do not induce social buffering. We found that the presence of a Wistar associate induced a reduction of behavioral responses and Fos expression in the paraventricular nucleus of the hypothalamus (PVN) of the subject. Although Fos expression in the AOP was increased, the expression was not biased towards the GABAergic cells. In addition, Fos expression in the lateral intercalated cell mass of the amygdala (lITC) was increased. In contrast, the presence of a F344 associate did not affect Fos expression in subjects' PVN or lITC, whereas behavioral responses were slightly reduced. These results suggest that the lITC was activated during social buffering. Based on these findings, we propose that the AOP indirectly suppresses the LA by activating the lITC.
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Affiliation(s)
- Shota Minami
- Laboratory of Veterinary Ethology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yasushi Kiyokawa
- Laboratory of Veterinary Ethology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
| | - Yukari Takeuchi
- Laboratory of Veterinary Ethology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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A model of amygdala function following plastic changes at specific synapses during extinction. Neurobiol Stress 2019; 10:100159. [PMID: 31193487 PMCID: PMC6535631 DOI: 10.1016/j.ynstr.2019.100159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 11/21/2022] Open
Abstract
The synaptic networks in the amygdala have been the subject of intense interest in recent times, primarily because of the role of this structure in emotion. Fear and its extinction depend on the workings of these networks, with particular interest in extinction because of its potential to ameliorate adverse symptoms associated with post-traumatic stress disorder. Here we place emphasis on the extinction networks revealed by recent techniques, and on the probable plasticity properties of their synaptic connections. We use modules of neurons representing each of the principal components identified as involved in extinction. Each of these modules consists of neural networks, containing specific ratios of excitatory and specialized inhibitory neurons as well as synaptic plasticity mechanisms appropriate for the component of the amygdala they represent. While these models can produce dynamic output, here we concentrate on the equilibrium outputs and do not model the details of the plasticity mechanisms. Pavlovian fear conditioning generates a fear memory in the lateral amygdala module that leads to activation of neurons in the basal nucleus fear module but not in the basal nucleus extinction module. Extinction protocols excite infralimbic medial prefrontal cortex neurons (IL) which in turn excite so-called extinction neurons in the amygdala, leading to the release of endocannabinoids from them and an increase in efficacy of synapses formed by lateral amygdala neurons on them. The model simulations show how such a mechanism could explain experimental observations involving the role of IL as well as endocannabinoids in different temporal phases of extinction.
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Mechanisms of fear learning and extinction: synaptic plasticity-fear memory connection. Psychopharmacology (Berl) 2019; 236:163-182. [PMID: 30415278 PMCID: PMC6374177 DOI: 10.1007/s00213-018-5104-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/02/2018] [Indexed: 12/21/2022]
Abstract
RATIONALE The ability to memorize threat-associated cues and subsequently react to them, exhibiting escape or avoidance responses, is an essential, often life-saving behavioral mechanism that can be experimentally studied using the fear (threat) conditioning training paradigm. Presently, there is substantial evidence supporting the Synaptic Plasticity-Memory (SPM) hypothesis in relation to the mechanisms underlying the acquisition, retention, and extinction of conditioned fear memory. OBJECTIVES The purpose of this review article is to summarize findings supporting the SPM hypothesis in the context of conditioned fear control, applying the set of criteria and tests which were proposed as necessary to causally link lasting changes in synaptic transmission in corresponding neural circuits to fear memory acquisition and extinction with an emphasis on their pharmacological diversity. RESULTS The mechanisms of synaptic plasticity in fear circuits exhibit complex pharmacological profiles and satisfy all four SPM criteria-detectability, anterograde alteration, retrograde alteration, and mimicry. CONCLUSION The reviewed findings, accumulated over the last two decades, provide support for both necessity and sufficiency of synaptic plasticity in fear circuits for fear memory acquisition and retention, and, in part, for fear extinction, with the latter requiring additional experimental work.
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Acute and long-lasting effects of oxytocin in cortico-limbic circuits: consequences for fear recall and extinction. Psychopharmacology (Berl) 2019; 236:339-354. [PMID: 30302511 DOI: 10.1007/s00213-018-5030-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 09/05/2018] [Indexed: 12/11/2022]
Abstract
The extinction of conditioned fear responses entrains the formation of safe new memories to decrease those behavioral responses. The knowledge in neuronal mechanisms of extinction is fundamental in the treatment of anxiety and fear disorders. Interestingly, the use of pharmacological compounds that reduce anxiety and fear has been shown as a potent co-adjuvant in extinction therapy. However, the efficiency and mechanisms by which pharmacological compounds promote extinction of fear memories remains still largely unknown and would benefit from a validation based on functional neuronal circuits, and the neurotransmitters that modulate them. From this perspective, oxytocin receptor signaling, which has been shown in cortical and limbic areas to modulate numerous functions (Eliava et al. Neuron 89(6):1291-1304, 2016), among them fear and anxiety circuits, and to enhance the salience of social stimuli (Stoop Neuron 76(1):142-59, 2012), may offer an interesting perspective. Experiments in animals and humans suggest that oxytocin could be a promising pharmacological agent at adjusting memory consolidation to boost fear extinction. Additionally, it is possible that long-term changes in endogenous oxytocin signaling can also play a role in reducing expression of fear at different brain targets. In this review, we summarize the effects reported for oxytocin in cortico-limbic circuits and on fear behavior that are of relevance for the modulation and potential extinction of fear memories.
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25
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Neurocircuitry of fear extinction in adult and juvenile rats. Behav Brain Res 2018; 351:161-167. [DOI: 10.1016/j.bbr.2018.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 05/12/2018] [Accepted: 06/01/2018] [Indexed: 01/14/2023]
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Orexin 2 receptor stimulation enhances resilience, while orexin 2 inhibition promotes susceptibility, to social stress, anxiety and depression. Neuropharmacology 2018; 143:79-94. [PMID: 30240784 DOI: 10.1016/j.neuropharm.2018.09.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 08/28/2018] [Accepted: 09/11/2018] [Indexed: 02/08/2023]
Abstract
Knockdown of orexin/hypocretin 2 receptor (Orx2) in the basolateral amygdala (BLA) affects anxious and depressive behavior. We use a new behavioral paradigm, the Stress Alternatives Model (SAM), designed to improve translational impact. The SAM induces social stress in adult male mice by aggression from larger mice, allowing for adaptive decision-making regarding escape. In this model, mice remain (Stay) in the oval SAM arena or escape from social aggression (Escape) via routes only large enough for the smaller mouse. We hypothesized intracerebroventricular (icv) stimulation of Orx2 receptors would be anxiolytic and antidepressive in SAM-related social behavior and the Social Interaction/Preference (SIP) test. Conversely, we predicted that icv antagonism of Orx2 receptors would promote anxious and depressive behavior in these same tests. Anxious behaviors such as freezing (both cued and conflict) and startle are exhibited more often in Stay compared with Escape phenotype mice. Time spent attentive to the escape route is more frequent in Escape mice. In Stay mice, stimulation of Orx2 receptors reduces fear conditioning, conflict freezing and startle, and promotes greater attention to the escape hole. This anxiolysis was accompanied by activation of a cluster of inhibitory neurons in the amygdala. A small percentage of those Stay mice also begin escaping; whereas Escape is reversed by the Orx2 antagonist. Escape mice were also Resilient, and Stay mice Susceptible to stress (SIP), with both conditions reversed by Orx2 antagonism or stimulation respectively. Together, these results suggest that the Orx2 receptor may be a useful potential target for anxiolytic or antidepressive therapeutics.
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Gregoriou GC, Kissiwaa SA, Patel SD, Bagley EE. Dopamine and opioids inhibit synaptic outputs of the main island of the intercalated neurons of the amygdala. Eur J Neurosci 2018; 50:2065-2074. [PMID: 30099803 DOI: 10.1111/ejn.14107] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 07/11/2018] [Accepted: 08/07/2018] [Indexed: 12/15/2022]
Abstract
Neural circuits in the amygdala are important for associating the positive experience of drug taking with the coincident environmental cues. During abstinence, cue re-exposure activates the amygdala, increases dopamine release in the amygdala and stimulates relapse to drug use in an opioid dependent manner. Neural circuits in the amygdala and the learning that underlies these behaviours are inhibited by GABAergic synaptic inhibition. A specialised subtype of GABAergic neurons in the amygdala are the clusters of intercalated cells. We focussed on the main-island of intercalated cells because these neurons, located ventromedial to the basolateral amygdala, express very high levels of dopamine D1-receptor and μ-opioid receptor, release enkephalin and are densely innervated by the ventral tegmental area. However, where these neurons project to was not fully described and their regulation by opioids and dopamine was incomplete. To address this issue we electrically stimulated in the main-island of the intercalated cells in rat brain slices and made patch-clamp recordings of GABAergic synaptics from amygdala neurons. We found that main-island neurons had a strong GABAergic inhibitory output to pyramidal neurons of the basolateral nucleus and the medial central nucleus, the major output zones of the amygdala. Opioids inhibited both these synaptic outputs of the intercalated neurons and thus would disinhibit these target zones. Additionally, dopamine acting at D1-receptors inhibited main-island neuron synapses onto other main-island neurons. This data indicates that the inhibitory projections from the main-island neurons could influence multiple aspects of addiction and emotional processing in an opioid and dopamine dependent manner.
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Affiliation(s)
- Gabrielle C Gregoriou
- Discipline of Pharmacology & Charles Perkins Centre, Charles Perkins Centre D17, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Sarah A Kissiwaa
- Discipline of Pharmacology & Charles Perkins Centre, Charles Perkins Centre D17, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Sahil D Patel
- Discipline of Pharmacology & Charles Perkins Centre, Charles Perkins Centre D17, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Elena E Bagley
- Discipline of Pharmacology & Charles Perkins Centre, Charles Perkins Centre D17, University of Sydney, Camperdown, NSW, 2006, Australia
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Krabbe S, Gründemann J, Lüthi A. Amygdala Inhibitory Circuits Regulate Associative Fear Conditioning. Biol Psychiatry 2018; 83:800-809. [PMID: 29174478 DOI: 10.1016/j.biopsych.2017.10.006] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 09/28/2017] [Accepted: 10/04/2017] [Indexed: 11/16/2022]
Abstract
Associative memory formation is essential for an animal's survival by ensuring adaptive behavioral responses in an ever-changing environment. This is particularly important under conditions of immediate threats such as in fear learning. One of the key brain regions involved in associative fear learning is the amygdala. The basolateral amygdala is the main entry site for sensory information to the amygdala complex, and local plasticity in excitatory basolateral amygdala principal neurons is considered to be crucial for learning of conditioned fear responses. However, activity and plasticity of excitatory circuits are tightly controlled by local inhibitory interneurons in a spatially and temporally defined manner. In this review, we provide an updated view on how distinct interneuron subtypes in the basolateral amygdala contribute to the acquisition and extinction of conditioned fear memories.
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Affiliation(s)
- Sabine Krabbe
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Jan Gründemann
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Andreas Lüthi
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; University of Basel, Basel, Switzerland.
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29
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Modulation of Neuronal Activity on Intercalated Neurons of Amygdala Might Underlie Anxiolytic Activity of a Standardized Extract of Centella asiatica ECa233. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 2018:3853147. [PMID: 29849706 PMCID: PMC5941724 DOI: 10.1155/2018/3853147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 03/07/2018] [Accepted: 03/25/2018] [Indexed: 11/18/2022]
Abstract
GABAergic intercalated neurons of amygdala (ITCs) have recently been shown to be important in the suppression of fear-like behavior. Effects of ECa233 (a standardized extract of Centella asiatica), previously demonstrated anxiolytic activity, were then investigated on ITCs. Cluster of GABAergic neurons expressing fluorescence of GFP was identified in GAD67-GFP knock-in mice. We found that neurons of medial paracapsular ITC were GABAergic neurons exhibiting certain intrinsic electrophysiological properties similar to those demonstrated by ITC neurons at the same location in C57BL/6J mice. Therefore, we conducted experiments in both C57BL/6J mice and GAD67-GFP knock-in mice. Excitatory postsynaptic currents (EPSCs) were evoked by stimulation of the external capsule during the whole cell patch-clamp recordings from ITC neurons in brain slices. ECa233 was found to increase the EPSC peak amplitude in the ITC neurons by about 120%. The EPSCs in ITC neurons were completely abolished by the application of an AMPA receptor antagonist. Morphological assessment of the ITC neurons with biocytin demonstrated that most axons of the recorded neurons innervated the central nucleus of the amygdala (CeA). Therefore, it is highly likely that anxiolytic activity of ECa233 was mediated by increasing activation, via AMPA receptors, of excitatory synaptic input to the GABAergic ITC leading to depression of CeA neurons.
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30
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Fear extinction requires infralimbic cortex projections to the basolateral amygdala. Transl Psychiatry 2018; 8:60. [PMID: 29507292 PMCID: PMC5838104 DOI: 10.1038/s41398-018-0106-x] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 10/17/2017] [Accepted: 10/26/2017] [Indexed: 11/15/2022] Open
Abstract
Fear extinction involves the formation of a new memory trace that attenuates fear responses to a conditioned aversive memory, and extinction impairments are implicated in trauma- and stress-related disorders. Previous studies in rodents have found that the infralimbic prefrontal cortex (IL) and its glutamatergic projections to the basolateral amygdala (BLA) and basomedial amygdala (BMA) instruct the formation of fear extinction memories. However, it is unclear whether these pathways are exclusively involved in extinction, or whether other major targets of the IL, such as the nucleus accumbens (NAc) also play a role. To address this outstanding issue, the current study employed a combination of electrophysiological and chemogenetic approaches in mice to interrogate the role of IL-BLA and IL-NAc pathways in extinction. Specifically, we used patch-clamp electrophysiology coupled with retrograde tracing to examine changes in neuronal activity of the IL and prelimbic cortex (PL) projections to both the BLA and NAc following fear extinction. We found that extinction produced a significant increase in the intrinsic excitability of IL-BLA projection neurons, while extinction appeared to reverse fear-induced changes in IL-NAc projection neurons. To establish a causal counterpart to these observations, we then used a pathway-specific Designer Receptors Exclusively Activated by Designer Drugs (DREADD) strategy to selectively inhibit PFC-BLA projection neurons during extinction acquisition. Using this approach, we found that DREADD-mediated inhibition of PFC-BLA neurons during extinction acquisition impaired subsequent extinction retrieval. Taken together, our findings provide further evidence for a critical contribution of the IL-BLA neural circuit to fear extinction.
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31
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Zussy C, Gómez-Santacana X, Rovira X, De Bundel D, Ferrazzo S, Bosch D, Asede D, Malhaire F, Acher F, Giraldo J, Valjent E, Ehrlich I, Ferraguti F, Pin JP, Llebaria A, Goudet C. Dynamic modulation of inflammatory pain-related affective and sensory symptoms by optical control of amygdala metabotropic glutamate receptor 4. Mol Psychiatry 2018; 23:509-520. [PMID: 27994221 DOI: 10.1038/mp.2016.223] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 10/06/2016] [Accepted: 10/14/2016] [Indexed: 12/30/2022]
Abstract
Contrary to acute pain, chronic pain does not serve as a warning signal and must be considered as a disease per se. This pathology presents a sensory and psychological dimension at the origin of affective and cognitive disorders. Being largely refractory to current pharmacotherapies, identification of endogenous systems involved in persistent and chronic pain is crucial. The amygdala is a key brain region linking pain sensation with negative emotions. Here, we show that activation of a specific intrinsic neuromodulatory system within the amygdala associated with type 4 metabotropic glutamate receptors (mGlu4) abolishes sensory and affective symptoms of persistent pain such as hypersensitivity to pain, anxiety- and depression-related behaviors, and fear extinction impairment. Interestingly, neuroanatomical and synaptic analysis of the amygdala circuitry suggests that the effects of mGlu4 activation occur outside the central nucleus via modulation of multisensory thalamic inputs to lateral amygdala principal neurons and dorso-medial intercalated cells. Furthermore, we developed optogluram, a small diffusible photoswitchable positive allosteric modulator of mGlu4. This ligand allows the control of endogenous mGlu4 activity with light. Using this photopharmacological approach, we rapidly and reversibly inhibited behavioral symptoms associated with persistent pain through optical control of optogluram in the amygdala of freely behaving animals. Altogether, our data identify amygdala mGlu4 signaling as a mechanism that bypasses central sensitization processes to dynamically modulate persistent pain symptoms. Our findings help to define novel and more precise therapeutic interventions for chronic pain, and exemplify the potential of optopharmacology to study the dynamic activity of endogenous neuromodulatory mechanisms in vivo.
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Affiliation(s)
- C Zussy
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, Université de Montpellier, Montpellier, France.,INSERM, U1191, Montpellier, France
| | - X Gómez-Santacana
- MCS, Laboratory of Medicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain.,Laboratory of Molecular Neuropharmacology and Bioinformatics, Institut de Neurociències and Unitat de Bioestadística, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - X Rovira
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, Université de Montpellier, Montpellier, France.,INSERM, U1191, Montpellier, France
| | - D De Bundel
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, Université de Montpellier, Montpellier, France.,INSERM, U1191, Montpellier, France
| | - S Ferrazzo
- Department of Pharmacology, Innsbruck Medical University, Innsbruck, Austria
| | - D Bosch
- Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - D Asede
- Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - F Malhaire
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, Université de Montpellier, Montpellier, France.,INSERM, U1191, Montpellier, France
| | - F Acher
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, CNRS UMR8601, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - J Giraldo
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Institut de Neurociències and Unitat de Bioestadística, Universitat Autònoma de Barcelona, Bellaterra, Spain.,Network Biomedical Research Center on Mental Health (CIBERSAM), Madrid, Spain
| | - E Valjent
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, Université de Montpellier, Montpellier, France.,INSERM, U1191, Montpellier, France
| | - I Ehrlich
- Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - F Ferraguti
- Department of Pharmacology, Innsbruck Medical University, Innsbruck, Austria
| | - J-P Pin
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, Université de Montpellier, Montpellier, France.,INSERM, U1191, Montpellier, France
| | - A Llebaria
- MCS, Laboratory of Medicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain
| | - C Goudet
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, Université de Montpellier, Montpellier, France.,INSERM, U1191, Montpellier, France
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Hitchcock LN, Lattal KM. Involvement of the dorsal hippocampus in expression and extinction of cocaine-induced conditioned place preference. Hippocampus 2018; 28:226-238. [PMID: 29341327 DOI: 10.1002/hipo.22826] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 01/05/2018] [Accepted: 01/13/2018] [Indexed: 12/31/2022]
Abstract
A key aspect of substance abuse is that drug taking often occurs in a specific context. As a consequence, exposure to drug-associated contexts can trigger cravings and relapse, even after long periods of abstinence. Although many studies have demonstrated that the hippocampus is critical for developing and retrieving contextual and spatial memories, comparatively little is known about the role of the hippocampus in acquiring and inhibiting memories involving contexts and drugs of abuse. We examined the effects of hippocampal inactivation on expression of cocaine-induced conditioned place preference (CPP) after initial acquisition or extinction of CPP in C57BL/6 mice. During acquisition of CPP, distinct tactile cues were paired with cocaine (20 mg kg-1 , intraperitoneal, CS+) and different tactile cues were paired with saline (CS-) on alternate days. Groups differed in whether the CS+ and CS- cues were presented in the same large space (one-compartment procedure) or distinct small spaces (two-compartment procedure), as previous findings demonstrate that a two-compartment configuration facilitates acquisition and attenuates extinction of a cocaine-induced CPP. Microinjection of the GABAA agonist, muscimol, into the dorsal hippocampus impaired (1) retrieval of a place preference after acquisition, (2) extinction of a place preference, and (3) retrieval of extinction. These effects differed depending on the spatial configuration during acquisition or extinction, suggesting that the dorsal hippocampus may differentially modulate drug seeking during retrieval and extinction of CPP.
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Affiliation(s)
- Leah N Hitchcock
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon
| | - K Matthew Lattal
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon
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33
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Aghajani M, Klapwijk ET, Colins OF, Ziegler C, Domschke K, Vermeiren RRJM, van der Wee NJA. Interactions Between Oxytocin Receptor Gene Methylation and Callous-Unemotional Traits Impact Socioaffective Brain Systems in Conduct-Disordered Offenders. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2018; 3:379-391. [PMID: 29628070 DOI: 10.1016/j.bpsc.2017.12.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 12/21/2017] [Accepted: 12/21/2017] [Indexed: 01/10/2023]
Abstract
BACKGROUND The developmental trajectory of psychopathy seemingly begins early in life and includes the presence of callous-unemotional (CU) traits (e.g., perturbed socioaffective reactivity and empathy, callousness) in youths with conduct disorder (CD). Whereas oxytocin receptor gene methylation (OXTRMeth) and its downstream neuromodulatory effects are deemed relevant to CU traits, nothing is known of how OXTRMeth interacts with CU traits to impact socioaffective brain systems in youngsters with CD. METHODS Hence, we uniquely probed OXTRMeth × CU trait interactions on corticolimbic activity and amygdala subregional connections during recognition and resonance of distressing socioaffective stimuli (angry and fearful faces), in juvenile offenders with CD (n = 39) versus matched healthy control youths (n = 27). RESULTS Relative to healthy control youths, elevated OXTRMeth and CU levels in youths with CD essentially interacted to predict frontoparietal hyperactivity and amygdalo-frontoparietal disconnection during task performance. Specifically, increasing OXTRMeth and CU levels in youths with CD interactively predicted midcingulate hyperactivity during both emotion conditions, with insular, temporoparietal, and precuneal hyperactivity additionally emerging during emotion recognition. Interactions between high OXTRMeth and CU levels in youths with CD additionally predicted centromedial amygdala decoupling from ventromedial/orbitofrontal regions during emotion recognition, along with basolateral amygdala decoupling from precuneal and temporoparietal cortices during emotion resonance. CONCLUSIONS These results uniquely suggest that interactions between OXTRMeth and CU traits in youths with CD may affect brain systems critical to decoding and integrating socioaffective information. Developmental models of CU traits and psychopathy could thus possibly advance by further examining OXTR epigenetic effects, which may hold promise for indicated prevention and personalized treatment by targeting oxytocinergic function.
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Affiliation(s)
- Moji Aghajani
- Department of Child and Adolescent Psychiatry, Curium, Leiden University Medical Center, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, Leiden, the Netherlands; Department of Psychiatry, VU University Medical Center, Amsterdam, the Netherlands.
| | - Eduard T Klapwijk
- Department of Child and Adolescent Psychiatry, Curium, Leiden University Medical Center, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, Leiden, the Netherlands; Brain and Development Research Center, Institute of Psychology, Leiden University, Leiden, the Netherlands
| | - Olivier F Colins
- Department of Child and Adolescent Psychiatry, Curium, Leiden University Medical Center, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Christiane Ziegler
- Department of Psychiatry and Psychotherapy, University Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Department of Psychiatry, University of Würzburg, Würzburg, Germany
| | | | - Robert R J M Vermeiren
- Department of Child and Adolescent Psychiatry, Curium, Leiden University Medical Center, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Nic J A van der Wee
- Department of Pschiatry, Curium, Leiden University Medical Center, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, Leiden, the Netherlands
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Loss of Intercalated Cells (ITCs) in the Mouse Amygdala of Tshz1 Mutants Correlates with Fear, Depression, and Social Interaction Phenotypes. J Neurosci 2017; 38:1160-1177. [PMID: 29255003 DOI: 10.1523/jneurosci.1412-17.2017] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 11/10/2017] [Accepted: 12/10/2017] [Indexed: 01/17/2023] Open
Abstract
The intercalated cells (ITCs) of the amygdala have been shown to be critical regulatory components of amygdalar circuits, which control appropriate fear responses. Despite this, the molecular processes guiding ITC development remain poorly understood. Here we establish the zinc finger transcription factor Tshz1 as a marker of ITCs during their migration from the dorsal lateral ganglionic eminence through maturity. Using germline and conditional knock-out (cKO) mouse models, we show that Tshz1 is required for the proper migration and differentiation of ITCs. In the absence of Tshz1, migrating ITC precursors fail to settle in their stereotypical locations encapsulating the lateral amygdala and BLA. Furthermore, they display reductions in the ITC marker Foxp2 and ectopic persistence of the dorsal lateral ganglionic eminence marker Sp8. Tshz1 mutant ITCs show increased cell death at postnatal time points, leading to a dramatic reduction by 3 weeks of age. In line with this, Foxp2-null mutants also show a loss of ITCs at postnatal time points, suggesting that Foxp2 may function downstream of Tshz1 in the maintenance of ITCs. Behavioral analysis of male Tshz1 cKOs revealed defects in fear extinction as well as an increase in floating during the forced swim test, indicative of a depression-like phenotype. Moreover, Tshz1 cKOs display significantly impaired social interaction (i.e., increased passivity) regardless of partner genetics. Together, these results suggest that Tshz1 plays a critical role in the development of ITCs and that fear, depression-like and social behavioral deficits arise in their absence.SIGNIFICANCE STATEMENT We show here that the zinc finger transcription factor Tshz1 is expressed during development of the intercalated cells (ITCs) within the mouse amygdala. These neurons have previously been shown to play a crucial role in fear extinction. Tshz1 mouse mutants exhibit severely reduced numbers of ITCs as a result of abnormal migration, differentiation, and survival of these neurons. Furthermore, the loss of ITCs in mouse Tshz1 mutants correlates well with defects in fear extinction as well as the appearance of depression-like and abnormal social interaction behaviors reminiscent of depressive disorders observed in human patients with distal 18q deletions, including the Tshz1 locus.
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35
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Interplay of prefrontal cortex and amygdala during extinction of drug seeking. Brain Struct Funct 2017; 223:1071-1089. [PMID: 29081007 PMCID: PMC5869906 DOI: 10.1007/s00429-017-1533-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 10/03/2017] [Indexed: 01/08/2023]
Abstract
Extinction of Pavlovian conditioning is a complex process that involves brain regions such as the medial prefrontal cortex (mPFC), the amygdala and the locus coeruleus. In particular, noradrenaline (NA) coming from the locus coeruleus has been recently shown to play a different role in two subregions of the mPFC, the prelimbic (PL) and the infralimbic (IL) regions. How these regions interact in conditioning and subsequent extinction is an open issue. We studied these processes using two approaches: computational modelling and NA manipulation in a conditioned place preference paradigm (CPP) in mice. In the computational model, NA in PL and IL causes inputs arriving to these regions to be amplified, thus allowing them to modulate learning processes in amygdala. The model reproduces results from studies involving depletion of NA from PL, IL, or both in CPP. In addition, we simulated new experiments of NA manipulations in mPFC, making predictions on the possible results. We searched the parameters of the model and tested the robustness of the predictions by performing a sensitivity analysis. We also present an empirical experiment where, in accord with the model, a double depletion of NA from both PL and IL in CPP with amphetamine impairs extinction. Overall the proposed model, supported by anatomical, physiological, and behavioural data, explains the differential role of NA in PL and IL and opens up the possibility to understand extinction mechanisms more in depth and hence to aid the development of treatments for disorders such as addiction.
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36
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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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37
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Woodhams SG, Chapman V, Finn DP, Hohmann AG, Neugebauer V. The cannabinoid system and pain. Neuropharmacology 2017; 124:105-120. [PMID: 28625720 PMCID: PMC5785108 DOI: 10.1016/j.neuropharm.2017.06.015] [Citation(s) in RCA: 182] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 05/31/2017] [Accepted: 06/14/2017] [Indexed: 01/20/2023]
Abstract
Chronic pain states are highly prevalent and yet poorly controlled by currently available analgesics, representing an enormous clinical, societal, and economic burden. Existing pain medications have significant limitations and adverse effects including tolerance, dependence, gastrointestinal dysfunction, cognitive impairment, and a narrow therapeutic window, making the search for novel analgesics ever more important. In this article, we review the role of an important endogenous pain control system, the endocannabinoid (EC) system, in the sensory, emotional, and cognitive aspects of pain. Herein, we briefly cover the discovery of the EC system and its role in pain processing pathways, before concentrating on three areas of current major interest in EC pain research; 1. Pharmacological enhancement of endocannabinoid activity (via blockade of EC metabolism or allosteric modulation of CB1receptors); 2. The EC System and stress-induced modulation of pain; and 3. The EC system & medial prefrontal cortex (mPFC) dysfunction in pain states. Whilst we focus predominantly on the preclinical data, we also include extensive discussion of recent clinical failures of endocannabinoid-related therapies, the future potential of these approaches, and important directions for future research on the EC system and pain. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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Affiliation(s)
- Stephen G Woodhams
- Arthritis UK Pain Centre, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom.
| | - Victoria Chapman
- Arthritis UK Pain Centre, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - David P Finn
- Pharmacology & Therapeutics, School of Medicine, Galway Neuroscience Centre and Centre for Pain Research, NCBES, National University of Ireland Galway, University Road, Galway, Ireland
| | - Andrea G Hohmann
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA; Program in Neuroscience, Indiana University, Bloomington, IN, USA; Interdisciplinary Biochemistry Graduate Program, Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA; Gill Center for Biomolecular Science, Indiana University, Bloomington, IN, USA
| | - Volker Neugebauer
- Department of Pharmacology and Neuroscience, Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
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Sharko AC, Fadel JR, Kaigler KF, Wilson MA. Activation of orexin/hypocretin neurons is associated with individual differences in cued fear extinction. Physiol Behav 2017; 178:93-102. [PMID: 27746261 PMCID: PMC5391308 DOI: 10.1016/j.physbeh.2016.10.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/23/2016] [Accepted: 10/11/2016] [Indexed: 01/15/2023]
Abstract
Identifying the neurobiological mechanisms that underlie differential sensitivity to stress is critical for understanding the development and expression of stress-induced disorders, such as post-traumatic stress disorder (PTSD). Preclinical studies have suggested that rodents display different phenotypes associated with extinction of Pavlovian conditioned fear responses, with some rodent populations being resistant to extinction. An emerging literature also suggests a role for orexins in the consolidation processes associated with fear learning and extinction. To examine the possibility that the orexin system might be involved in individual differences in fear extinction, we used a Pavlovian conditioning paradigm in outbred Long-Evans rats. Rats showed significant variability in the extinction of cue-conditioned freezing and extinction recall, and animals were divided into groups based on their extinction profiles based on a median split of percent freezing behavior during repeated exposure to the conditioned cue. Animals resistant to extinction (high freezers) showed more freezing during repeated cue presentations during the within trial and between trial extinction sessions compared with the group showing significant extinction (low freezers), although there were no differences between these groups in freezing upon return to the conditioned context or during the conditioning session. Following the extinction recall session, activation of orexin neurons was determined using dual label immunohistochemistry for cFos in orexin positive neurons in the hypothalamus. Individual differences in the extinction of cue conditioned fear were associated with differential activation of hypothalamic orexin neurons. Animals showing poor extinction of cue-induced freezing (high freezers) had significantly greater percentage of orexin neurons with Fos in the medial hypothalamus than animals displaying significant extinction and good extinction recall (low freezers). Further, the freezing during extinction learning was positively correlated with the percentage of activated orexin neurons in both the lateral and medial hypothalamic regions. No differences in the overall density of orexin neurons or Fos activation were seen between extinction phenotypes. Although correlative, our results support other studies implicating a role of the orexinergic system in regulating extinction of conditioned responses to threat.
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Affiliation(s)
- Amanda C Sharko
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina, School of Medicine, Columbia, SC, USA; WJB Dorn Veterans Affairs Medical Center, Columbia, SC, USA
| | - Jim R Fadel
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina, School of Medicine, Columbia, SC, USA; WJB Dorn Veterans Affairs Medical Center, Columbia, SC, USA
| | - Kris F Kaigler
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina, School of Medicine, Columbia, SC, USA; WJB Dorn Veterans Affairs Medical Center, Columbia, SC, USA
| | - Marlene A Wilson
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina, School of Medicine, Columbia, SC, USA; WJB Dorn Veterans Affairs Medical Center, Columbia, SC, USA.
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Strobel C, Sullivan RKP, Stratton P, Sah P. Calcium signalling in medial intercalated cell dendrites and spines. J Physiol 2017; 595:5653-5669. [PMID: 28594440 DOI: 10.1113/jp274261] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/05/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Dendritic and spine calcium imaging in combination with electrophysiology in acute slices revealed that in medial intercalated cells of the amygdala: Action potentials back-propagate into the dendritic tree, but due to the presence of voltage-dependent potassium channels, probably Kv4.2 channels, attenuate over distance. A mixed population of AMPA receptors with rectifying and linear I-V relations are present at individual spines of a single neuron. Decay kinetics and pharmacology suggest tri-heteromeric NMDA receptors at basolateral-intercalated cell synapses. NMDA receptors are the main contributors to spine calcium entry in response to synaptic stimulation. Calcium signals in response to low- and high-frequency stimulation, and in combination with spontaneous action potentials are locally restricted to the vicinity of active spines. Together, these data show that calcium signalling in these GABAergic neurons is tightly controlled and acts as a local signal. ABSTRACT The amygdala plays a central role in fear conditioning and extinction. The medial intercalated (mITC) neurons are GABAergic cell clusters interspaced between the basolateral (BLA) and central amygdala (CeA). These neurons are thought to play a key role in fear and extinction, controlling the output of the CeA by feed-forward inhibition. BLA to mITC cell inputs are thought to undergo synaptic plasticity, a mechanism underlying learning, which is mediated by NMDA receptor-dependent mechanisms that require changes in cytosolic calcium. Here, we studied the electrical and calcium signalling properties of mITC neurons in GAD67-eGFP mice using whole-cell patch clamp recordings and two-photon calcium imaging. We show that action potentials back-propagate (bAP) into dendrites, and evoke calcium transients in both the shaft and the dendritic spine. However, bAP-mediated calcium rises in the dendrites attenuate with distance due to shunting by voltage-gated potassium channels. Glutamatergic inputs make dual component synapses on spines. At these synapses, postsynaptic AMPA receptors can have linear or rectifying I-V relationships, indicating that some synapses express GluA2-lacking AMPA receptors. Synaptic NMDA receptors had intermediate decay kinetics, and were only partly blocked by GuN2B selective blockers, indicating these receptors are GluN1/GluN2A/GluN2B trimers. Low- or high-frequency synaptic stimulation raised spine calcium, mediated by calcium influx via NMDA receptors, was locally restricted and did not invade neighbouring spines. Our results show that in mITC neurons, postsynaptic calcium is tightly controlled, and acts as a local signal.
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Affiliation(s)
- Cornelia Strobel
- Queensland Brain Institute and School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Robert K P Sullivan
- Queensland Brain Institute and School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Peter Stratton
- Queensland Brain Institute and School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Pankaj Sah
- Queensland Brain Institute and School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
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[Oxytocin and the mechanisms of alcohol dependence]. NEUROPSYCHIATRIE : KLINIK, DIAGNOSTIK, THERAPIE UND REHABILITATION : ORGAN DER GESELLSCHAFT ÖSTERREICHISCHER NERVENÄRZTE UND PSYCHIATER 2017. [PMID: 28639210 DOI: 10.1007/s40211-017-0229-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
One of the crucial purposes of treating alcohol-dependent patients is to enhance their ability to stay abstinent after detoxification therapy. Anxiety and stress vulnerability are the main factors provoking alcohol craving and relapse. In the first months of abstinence, alcohol-dependent patients frequently show sleep disturbances, irritability and depression, indicating chronic activation of stress pathways. In addition, the loss of confidence in interpersonal interactions results in social withdrawal and reduced willingness to participate in therapeutic programs.Current research shows that the peptide hormone oxytocin exerts substantial anxiolytic effects and facilitates prosocial behavior. Oxytocin can be safely applied as intranasal preparation. Oxytocin acts by inhibiting the effects of the corticotropin-releasing factor on GABAergic interneurons in the amygdala and paraventricular nucleus of hypothalamus.Recent research strongly suggests that application of oxytocin may beneficially influence the mechanisms of relapse and craving by reduction of anxiety, stress vulnerability and social withdrawal in abstinent alcohol-dependent patients.This article reviews neurobiological mechanisms of oxytocin effects on stress-related pathways and discusses the potential use of oxytocin in the treatment of alcohol addiction.
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Calakos KC, Blackman D, Schulz AM, Bauer EP. Distribution of type I corticotropin-releasing factor (CRF1) receptors on GABAergic neurons within the basolateral amygdala. Synapse 2017; 71:10.1002/syn.21953. [PMID: 27997737 PMCID: PMC7876706 DOI: 10.1002/syn.21953] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 11/21/2016] [Accepted: 12/02/2016] [Indexed: 12/23/2022]
Abstract
The neuropeptide corticotropin-releasing factor (CRF) plays a critical role in mediating anxiety-like responses to stressors, and dysfunction of the CRF system has been linked to the etiology of several psychiatric disorders. Extra-hypothalamic CRF can also modulate learning and memory formation, including amygdala-dependent learning. The basolateral nucleus of the amygdala (BLA) contains dense concentrations of CRF receptors, yet the distribution of these receptors on specific neuronal subtypes within the BLA has not been characterized. Here, we quantified the expression of CRF receptors on three nonoverlapping classes of GABAergic interneurons: those containing the calcium-binding protein parvalbumin (PV), and those expressing the neuropeptides somatostatin (SOM) or cholecystokinin (CCK). While the majority of PV+ neurons and roughly half of CCK+ neurons expressed CRF receptors, they were expressed to a much lesser extent on SOM+ interneurons. Knowledge of the distribution of CRF receptors within the BLA can provide insight into how manipulations of the CRF system modulate fear and anxiety-like behaviors.
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Affiliation(s)
- Katina C Calakos
- Barnard College Columbia University, 3009 Broadway, New York, New York, 10027
| | - Dakota Blackman
- Barnard College Columbia University, 3009 Broadway, New York, New York, 10027
| | - Alexandra M Schulz
- Barnard College Columbia University, 3009 Broadway, New York, New York, 10027
| | - Elizabeth P Bauer
- Barnard College Columbia University, 3009 Broadway, New York, New York, 10027
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Endogenous opioids regulate moment-to-moment neuronal communication and excitability. Nat Commun 2017; 8:14611. [PMID: 28327612 PMCID: PMC5364458 DOI: 10.1038/ncomms14611] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 01/14/2017] [Indexed: 01/12/2023] Open
Abstract
Fear and emotional learning are modulated by endogenous opioids but the cellular basis for this is unknown. The intercalated cells (ITCs) gate amygdala output and thus regulate the fear response. Here we find endogenous opioids are released by synaptic stimulation to act via two distinct mechanisms within the main ITC cluster. Endogenously released opioids inhibit glutamate release through the δ-opioid receptor (DOR), an effect potentiated by a DOR-positive allosteric modulator. Postsynaptically, the opioids activate a potassium conductance through the μ-opioid receptor (MOR), suggesting for the first time that endogenously released opioids directly regulate neuronal excitability. Ultrastructural localization of endogenous ligands support these functional findings. This study demonstrates a new role for endogenously released opioids as neuromodulators engaged by synaptic activity to regulate moment-to-moment neuronal communication and excitability. These distinct actions through MOR and DOR may underlie the opposing effect of these receptor systems on anxiety and fear. The endogenous opioid system regulates fear and anxiety, but the underlying cellular mechanism is unclear. Winters et al. shows that in the intercalated cells (ITC) of the amygdala, endogenous opioids suppress glutamatergic inputs via the δ-opioid receptor presynaptically, and reduce the excitability of ITCs via the μ-opioid receptor postsynaptically.
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Postnatal development of neurotransmitter systems and their relevance to extinction of conditioned fear. Neurobiol Learn Mem 2017; 138:252-270. [DOI: 10.1016/j.nlm.2016.10.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 10/22/2016] [Accepted: 10/31/2016] [Indexed: 12/14/2022]
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Westberry JM, Meredith M. Characteristic Response to Chemosensory Signals in GABAergic Cells of Medial Amygdala Is Not Driven by Main Olfactory Input. Chem Senses 2017; 42:13-24. [PMID: 27651427 PMCID: PMC5155562 DOI: 10.1093/chemse/bjw096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Chemosensory stimuli from same species (conspecific) and different species (heterospecific) elicit categorically different immediate-early gene (IEG) response patterns in medial amygdala in male hamsters and mice. All heterospecific stimuli activate anterior medial amygdala (MeA) but only especially salient heterospecific stimuli, such as those from predators activate posterior medial amygdala (MeP). We previously reported that characteristic patterns of response in separate populations of cells in MeA and MeP distinguish between different conspecific stimuli. Both gamma aminobutyric acid (GABA)-immunoreactive (ir) cells and GABA-receptor-ir cells make this distinction. Here, using zinc sulfate lesions of the main olfactory epithelium, we show evidence that main olfactory input does not contribute to the characteristic patterns of response in GABA-ir cells of male hamster amygdala, either for conspecific or heterospecific stimuli. Some GABAergic cells are output neurons carrying information from medial amygdala to behavioral executive regions of basal forebrain. Thus, the differential response to different conspecific signals can lead to differential activation of downstream circuits based on nonolfactory input. Finally, we show that an intact vomeronasal organ is necessary and sufficient to produce the characteristic patterns of response to conspecific and heterospecific chemosensory stimuli in hamster medial amygdala. Although main olfactory input may be critical in species with less prominent vomeronasal input for equivalent medial amygdala responses, work presented here suggests that hamster medial amygdala uses primarily vomeronasal input to discriminate between important unlearned conspecific social signals, to distinguish them from the social signals of other species, and may convey that information to brain circuits eliciting appropriate social behavior.
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Affiliation(s)
- Jenne M Westberry
- Present address: Department of Biology, University of St. Thomas, St. Paul, MN 555105, USA
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McCullough KM, Morrison FG, Ressler KJ. Bridging the Gap: Towards a cell-type specific understanding of neural circuits underlying fear behaviors. Neurobiol Learn Mem 2016; 135:27-39. [PMID: 27470092 PMCID: PMC5123437 DOI: 10.1016/j.nlm.2016.07.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/22/2016] [Accepted: 07/25/2016] [Indexed: 11/15/2022]
Abstract
Fear and anxiety-related disorders are remarkably common and debilitating, and are often characterized by dysregulated fear responses. Rodent models of fear learning and memory have taken great strides towards elucidating the specific neuronal circuitries underlying the learning of fear responses. The present review addresses recent research utilizing optogenetic approaches to parse circuitries underlying fear behaviors. It also highlights the powerful advances made when optogenetic techniques are utilized in a genetically defined, cell-type specific, manner. The application of next-generation genetic and sequencing approaches in a cell-type specific context will be essential for a mechanistic understanding of the neural circuitry underlying fear behavior and for the rational design of targeted, circuit specific, pharmacologic interventions for the treatment and prevention of fear-related disorders.
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Affiliation(s)
- K M McCullough
- Department of Psychiatry and Behavioral Sciences and Yerkes National Primate Research Center, Emory University, Atlanta, Georgia; Department of Graduate Program in Neuroscience, Emory University, Atlanta, Georgia; Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, United States.
| | - F G Morrison
- Department of Psychiatry and Behavioral Sciences and Yerkes National Primate Research Center, Emory University, Atlanta, Georgia; Department of Graduate Program in Neuroscience, Emory University, Atlanta, Georgia; Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, United States
| | - K J Ressler
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, United States
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46
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Westberry JM, Meredith M. GABAergic mechanisms contributing to categorical amygdala responses to chemosensory signals. Neuroscience 2016; 331:186-96. [PMID: 27329335 PMCID: PMC4955787 DOI: 10.1016/j.neuroscience.2016.06.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 05/24/2016] [Accepted: 06/10/2016] [Indexed: 11/15/2022]
Abstract
Chemosensory stimuli from conspecific and heterospecific animals, elicit categorically different immediate-early gene response-patterns in medial amygdala in male hamsters and mice. We previously showed that conspecific signals activate posterior (MeP) as well as anterior medial amygdala (MeA), and especially relevant heterospecific signals such as chemosensory stimuli from potential predators also activate MeP in mice. Other heterospecific chemosignals activate MeA, but not MeP. Here we show that male hamster amygdala responds significantly differentially to different conspecific signals, by activating different proportions of cells of different phenotype, possibly leading to differential activation of downstream circuits. Heterospecific signals that fail to activate MeP do activate GABA-immunoreactive cells in the adjacent caudal main intercalated nucleus (mICNc) and elicit selective suppression of MeP cells bearing GABA-Receptors, suggesting GABA inhibition in MeP by GABAergic cells in mICNc. Overall, work presented here suggests that medial amygdala may discriminate between important conspecific social signals, distinguish them from the social signals of other species and convey that information to brain circuits eliciting appropriate social behavior.
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Affiliation(s)
- Jenne M Westberry
- Program in Neuroscience and Department Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA.
| | - Michael Meredith
- Program in Neuroscience and Department Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA.
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Rebolledo-Solleiro D, Araiza LFO, Broccoli L, Hansson AC, Rocha-Arrieta LL, Aguilar-Roblero R, Crespo-Ramírez M, Fuxe K, Pérez de la Mora M. Dopamine D1 receptor activity is involved in the increased anxiety levels observed in STZ-induced diabetes in rats. Behav Brain Res 2016; 313:293-301. [PMID: 27374159 DOI: 10.1016/j.bbr.2016.06.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/26/2016] [Accepted: 06/29/2016] [Indexed: 12/31/2022]
Abstract
Epidemiological surveys have indicated that anxiety disorders are more frequent in diabetic patients than in the general population. Similar results have been shown in animal studies using the streptozotocin (STZ)-induced diabetes model. The mechanisms underlying this relationship are not clearly understood, but it has been suggested that alterations in the dopaminergic neurotransmission, which plays an important role in the amygdaloid modulation of fear and anxiety, may be involved. The aim of this study was to ascertain whether or not the amygdaloid DA D1 receptors are involved in the increase of anxiety-like behavior observed in "diabetic" animals. Adult Wistar male rats were injected with STZ (50mg/kg, i.p.) in two consecutive days and subjected to the Shock-Probe Burying Test 10days after the beginning of treatment. STZ-treated rats showed a significant increase in immobility/freezing behavior whereas no effects were elicited in latency to bury, burying behavior itself and the number of shocks received during testing as compared with non-diabetic controls. These results suggest the triggering of a passive coping response in the STZ-treated rats. Interestingly, immobility/freezing behavior was reversed following the intra-amygdaloid dopamine D1 receptor blockade by the local microinfusion of SCH23390 (100ng/side). Autoradiographic experiments showed a selective increase of [(3)H]-SCH23390 binding in the ventral intercalated paracapsular islands of STZ-treated rats when compared to the non-treated control group. Our results suggest that a hyperdopaminergic state involving DA D1 receptors within the amygdala may have a role in the increase of anxiety observed in diabetic rats.
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Affiliation(s)
- Daniela Rebolledo-Solleiro
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | - Laura Broccoli
- Neuroanatomy Research Group, Institute for Psychopharmacology at Central Institute for Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Anita C Hansson
- Neuroanatomy Research Group, Institute for Psychopharmacology at Central Institute for Mental Health, Medical Faculty Mannheim, University of Heidelberg, Germany
| | - Luisa Lilia Rocha-Arrieta
- Department of Pharmacobiology, Instituto de Investigación y Estudios Avanzados (CINVESTAV) Sede Sur, Mexico City, Mexico
| | - Raúl Aguilar-Roblero
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Minerva Crespo-Ramírez
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Kjell Fuxe
- Division of Cellular and Molecular Neurochemistry, Department of Neuroscience, Karolinska Institutet, Sweden
| | - Miguel Pérez de la Mora
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico.
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Zikopoulos B, John YJ, García-Cabezas MÁ, Bunce JG, Barbas H. The intercalated nuclear complex of the primate amygdala. Neuroscience 2016; 330:267-90. [PMID: 27256508 DOI: 10.1016/j.neuroscience.2016.05.052] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 05/09/2016] [Accepted: 05/26/2016] [Indexed: 12/20/2022]
Abstract
The organization of the inhibitory intercalated cell masses (IM) of the primate amygdala is largely unknown despite their key role in emotional processes. We studied the structural, topographic, neurochemical and intrinsic connectional features of IM neurons in the rhesus monkey brain. We found that the intercalated neurons are not confined to discrete cell clusters, but form a neuronal net that is interposed between the basal nuclei and extends to the dorsally located anterior, central, and medial nuclei of the amygdala. Unlike the IM in rodents, which are prominent in the anterior half of the amygdala, the primate inhibitory net stretched throughout the antero-posterior axis of the amygdala, and was most prominent in the central and posterior extent of the amygdala. There were two morphologic types of intercalated neurons: spiny and aspiny. Spiny neurons were the most abundant; their somata were small or medium size, round or elongated, and their dendritic trees were round or bipolar, depending on location. The aspiny neurons were on average slightly larger and had varicose dendrites with no spines. There were three non-overlapping neurochemical populations of IM neurons, in descending order of abundance: (1) Spiny neurons that were positive for the striatal associated dopamine- and cAMP-regulated phosphoprotein (DARPP-32+); (2) Aspiny neurons that expressed the calcium-binding protein calbindin (CB+); and (3) Aspiny neurons that expressed nitric oxide synthase (NOS+). The unique combinations of structural and neurochemical features of the three classes of IM neurons suggest different physiological properties and function. The three types of IM neurons were intermingled and likely interconnected in distinct ways, and were innervated by intrinsic neurons within the amygdala, or by external sources, in pathways that underlie fear conditioning and anxiety.
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Affiliation(s)
- Basilis Zikopoulos
- Human Systems Neuroscience Laboratory, Department of Health Sciences, Boston University, Boston, MA, United States; Graduate Program for Neuroscience, Boston University and School of Medicine, Boston, MA, United States.
| | - Yohan J John
- Neural Systems Laboratory, Department of Health Sciences, Boston University, Boston, MA, United States
| | | | - Jamie G Bunce
- Neural Systems Laboratory, Department of Health Sciences, Boston University, Boston, MA, United States
| | - Helen Barbas
- Graduate Program for Neuroscience, Boston University and School of Medicine, Boston, MA, United States; Neural Systems Laboratory, Department of Health Sciences, Boston University, Boston, MA, United States
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49
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Schönherr S, Seewald A, Kasugai Y, Bosch D, Ehrlich I, Ferraguti F. Combined Optogenetic and Freeze-fracture Replica Immunolabeling to Examine Input-specific Arrangement of Glutamate Receptors in the Mouse Amygdala. J Vis Exp 2016. [PMID: 27167567 PMCID: PMC4941933 DOI: 10.3791/53853] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Freeze-fracture electron microscopy has been a major technique in ultrastructural research for over 40 years. However, the lack of effective means to study the molecular composition of membranes produced a significant decline in its use. Recently, there has been a major revival in freeze-fracture electron microscopy thanks to the development of effective ways to reveal integral membrane proteins by immunogold labeling. One of these methods is known as detergent-solubilized Freeze-fracture Replica Immunolabeling (FRIL). The combination of the FRIL technique with optogenetics allows a correlated analysis of the structural and functional properties of central synapses. Using this approach it is possible to identify and characterize both pre- and postsynaptic neurons by their respective expression of a tagged channelrhodopsin and specific molecular markers. The distinctive appearance of the postsynaptic membrane specialization of glutamatergic synapses further allows, upon labeling of ionotropic glutamate receptors, to quantify and analyze the intrasynaptic distribution of these receptors. Here, we give a step-by-step description of the procedures required to prepare paired replicas and how to immunolabel them. We will also discuss the caveats and limitations of the FRIL technique, in particular those associated with potential sampling biases. The high reproducibility and versatility of the FRIL technique, when combined with optogenetics, offers a very powerful approach for the characterization of different aspects of synaptic transmission at identified neuronal microcircuits in the brain. Here, we provide an example how this approach was used to gain insights into structure-function relationships of excitatory synapses at neurons of the intercalated cell masses of the mouse amygdala. In particular, we have investigated the expression of ionotropic glutamate receptors at identified inputs originated from the thalamic posterior intralaminar and medial geniculate nuclei. These synapses were shown to relay sensory information relevant for fear learning and to undergo plastic changes upon fear conditioning.
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Affiliation(s)
| | - Anna Seewald
- Department of Pharmacology, Medical University of Innsbruck
| | - Yu Kasugai
- Department of Pharmacology, Medical University of Innsbruck
| | - Daniel Bosch
- Hertie Institute for Clinical Brain Research and Centre for Integrative Neuroscience, University of Tübingen
| | - Ingrid Ehrlich
- Hertie Institute for Clinical Brain Research and Centre for Integrative Neuroscience, University of Tübingen
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50
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Bosch D, Asede D, Ehrlich I. Ex Vivo Optogenetic Dissection of Fear Circuits in Brain Slices. J Vis Exp 2016:e53628. [PMID: 27077317 DOI: 10.3791/53628] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Optogenetic approaches are now widely used to study the function of neural populations and circuits by combining targeted expression of light-activated proteins and subsequent manipulation of neural activity by light. Channelrhodopsins (ChRs) are light-gated cation-channels and when fused to a fluorescent protein their expression allows for visualization and concurrent activation of specific cell types and their axonal projections in defined areas of the brain. Via stereotactic injection of viral vectors, ChR fusion proteins can be constitutively or conditionally expressed in specific cells of a defined brain region, and their axonal projections can subsequently be studied anatomically and functionally via ex vivo optogenetic activation in brain slices. This is of particular importance when aiming to understand synaptic properties of connections that could not be addressed with conventional electrical stimulation approaches, or in identifying novel afferent and efferent connectivity that was previously poorly understood. Here, a few examples illustrate how this technique can be applied to investigate these questions to elucidating fear-related circuits in the amygdala. The amygdala is a key region for acquisition and expression of fear, and storage of fear and emotional memories. Many lines of evidence suggest that the medial prefrontal cortex (mPFC) participates in different aspects of fear acquisition and extinction, but its precise connectivity with the amygdala is just starting to be understood. First, it is shown how ex vivo optogenetic activation can be used to study aspects of synaptic communication between mPFC afferents and target cells in the basolateral amygdala (BLA). Furthermore, it is illustrated how this ex vivo optogenetic approach can be applied to assess novel connectivity patterns using a group of GABAergic neurons in the amygdala, the paracapsular intercalated cell cluster (mpITC), as an example.
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Affiliation(s)
- Daniel Bosch
- Hertie Institute for Clinical Brain Research and Werner Reichardt Centre for Integrative Neuroscience, University of Tuebingen
| | | | - Ingrid Ehrlich
- Hertie Institute for Clinical Brain Research and Werner Reichardt Centre for Integrative Neuroscience, University of Tuebingen;
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