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Kornhuber J, Zoicas I. Valence-dependent effects of neuropeptide Y on the expression of conditioned fear and anxiety-like behavior: Involvement of the bed nucleus of the stria terminalis. Neuropharmacology 2024; 246:109847. [PMID: 38218578 DOI: 10.1016/j.neuropharm.2024.109847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 01/03/2024] [Accepted: 01/10/2024] [Indexed: 01/15/2024]
Abstract
Neuropeptide Y (NPY) has anxiolytic-like effects and facilitates the extinction of cued and contextual fear in rodents. We have previously shown that intracerebroventricular administration of NPY reduces the expression of social fear via simultaneous activation of Y1 and Y2 receptors in a mouse model of social fear conditioning (SFC). In the present study, we investigated whether the anteroventral bed nucleus of the stria terminalis (BNSTav) mediates these effects of NPY, given the important role of BNSTav in regulating anxiety- and fear-related behaviors. We show that while NPY (0.1 nmol/0.2 μl/side) did not reduce the expression of SFC-induced social fear in male CD1 mice, it reduced the expression of both cued and contextual fear by acting on Y2 but not on Y1 receptors within the BNSTav. Prior administration of the Y2 receptor antagonist BIIE0246 (0.2 nmol/0.2 μl/side) but not of the Y1 receptor antagonist BIBO3304 trifluoroacetate (0.2 nmol/0.2 μl/side) blocked the effects of NPY on the expression of cued and contextual fear. Similarly, NPY exerted non-social anxiolytic-like effects in the elevated plus maze test but not social anxiolytic-like effects in the social approach avoidance test by acting on Y2 receptors and not on Y1 receptors within the BNSTav. These results suggest that administration of NPY within the BNSTav exerts robust Y2 receptor-mediated fear-reducing and anxiolytic-like effects specifically in non-social contexts and add a novel piece of evidence regarding the neural underpinnings underlying the effects of NPY on conditioned fear and anxiety-like behavior.
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Affiliation(s)
- Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Iulia Zoicas
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany.
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2
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Xu L, Zhang J, Yang H, Cao C, Fang R, Liu P, Luo S, Wang B, Zhang K, Wang L. Epistasis in neurotransmitter receptors linked to posttraumatic stress disorder and major depressive disorder comorbidity in traumatized Chinese. Front Psychiatry 2024; 15:1257911. [PMID: 38487579 PMCID: PMC10937445 DOI: 10.3389/fpsyt.2024.1257911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 02/14/2024] [Indexed: 03/17/2024] Open
Abstract
Background Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) comorbidity occurs through exposure to trauma with genetic susceptibility. Neuropeptide-Y (NPY) and dopamine are neurotransmitters associated with anxiety and stress-related psychiatry through receptors. We attempted to explore the genetic association between two neurotransmitter receptor systems and the PTSD-MDD comorbidity. Methods Four groups were identified using latent profile analysis (LPA) to examine the patterns of PTSD and MDD comorbidity among survivors exposed to earthquake-related trauma: low symptoms, predominantly depression, predominantly PTSD, and PTSD-MDD comorbidity. NPY2R (rs4425326), NPY5R (rs11724320), DRD2 (rs1079597), and DRD3 (rs6280) were genotyped from 1,140 Chinese participants exposed to earthquake-related trauma. Main, gene-environment interaction (G × E), and gene-gene interaction (G × G) effects for low symptoms, predominantly depression, and predominantly PTSD were tested using a multinomial logistic model with PTSD-MDD comorbidity as a reference. Results The results demonstrated that compared to PTSD-MDD comorbidity, epistasis (G × G) NPY2R-DRD2 (rs4425326 × rs1079597) affects low symptoms (β = -0.66, OR = 0.52 [95% CI: 0.32-0.84], p = 0.008, pperm = 0.008) and predominantly PTSD (β = -0.56, OR = 0.57 [95% CI: 0.34-0.97], p = 0.037, pperm = 0.039), while NPY2R-DRD3 (rs4425326 × rs6280) impacts low symptoms (β = 0.82, OR = 2.27 [95% CI: 1.26-4.10], p = 0.006, pperm = 0.005) and predominantly depression (β = 1.08, R = 2.95 [95% CI: 1.55-5.62], p = 0.001, pperm = 0.001). The two G × G effects are independent. Conclusion NPY and dopamine receptor genes are related to the genetic etiology of PTSD-MDD comorbidity, whose specific mechanisms can be studied at multiple levels.
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Affiliation(s)
- Ling Xu
- Laboratory for Traumatic Stress Studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Jingyi Zhang
- Laboratory for Traumatic Stress Studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Haibo Yang
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
| | - Chengqi Cao
- Laboratory for Traumatic Stress Studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Ruojiao Fang
- Laboratory for Traumatic Stress Studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Ping Liu
- People’s Hospital of Deyang City, Deyang, Sichuan, China
| | - Shu Luo
- People’s Hospital of Deyang City, Deyang, Sichuan, China
| | - Binbin Wang
- Laboratory for Traumatic Stress Studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Kunlin Zhang
- Laboratory for Traumatic Stress Studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Li Wang
- Laboratory for Traumatic Stress Studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
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Sabban EL, Serova L, Nahvi RJ, Liu X. Potential benefits of intranasal neuropeptide Y include sustained extinction of fear memory. J Neuroendocrinol 2023; 35:e13279. [PMID: 37157881 DOI: 10.1111/jne.13279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/03/2023] [Accepted: 04/10/2023] [Indexed: 05/10/2023]
Abstract
Compelling evidence in animals and humans from a variety of approaches demonstrate that neuropeptide Y (NPY) in the brain can provide resilience to development of many stress-elicited symptoms. Preclinical experiments demonstrated that delivery of NPY by intranasal infusion to rats shortly after single exposure to traumatic stress in the single prolonged stress (SPS) rodent model of post-traumatic stress disorder (PTSD) can prevent development of many relevant behavioral alterations weeks later, including heightened anxiety and depressive-like behavior. Here, we examined responses to intranasal NPY in the absence of stress to evaluate the safety profile. Rats were administered intranasal NPY (150 μg/rat) or equal volume of vehicle (distilled water), and 7 days later they were tested on the elevated plus maze (EPM) and forced swim test (FST). There was no significant difference in the number of entries or duration in the open or closed arms, or in their anxiety index. Defecation on the EPM and immobility on the FST, measures of anxiety and depressive-like behavior respectively, were similar in both groups. To further characterize potential benefits of intranasal NPY, its effect on fear memory and extinction, important features of PTSD, were examined. Intranasal administration of NPY at the time of the traumatic stress had a profound effect on fear conditioning a week later. It prevented the SPS-triggered impairment in the retention of extinguished behavior, both contextual and cued. The findings support the translation of non-invasive intranasal NPY delivery to the brain for PTSD-behaviors including impairments in sustained extinction of fear memories.
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Affiliation(s)
- Esther L Sabban
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Lidia Serova
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Roxanna J Nahvi
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Xiaoping Liu
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
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Mertens YL, Manthey A, Sierk A, de Jong P, Walter H, Daniels JK. A pharmacological challenge paradigm to assess neural signatures of script-elicited acute dissociation in women with post-traumatic stress disorder. BJPsych Open 2023; 9:e78. [PMID: 37128866 DOI: 10.1192/bjo.2023.34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND There is limited experimentally controlled neuroimaging research available that could explain how dissociative states occur and which neurobiological changes are involved in acute post-traumatic dissociation. AIMS To test the causal hypothesis that acute dissociation is triggered bottom-up by a selective noradrenergic-mediated increase in amygdala activation during the processing of autobiographical trauma memories. METHOD Women with post-traumatic stress disorder (n = 47) and a history of interpersonal childhood trauma underwent a within-participant, placebo-controlled pharmacological challenge paradigm (4.0 mg reboxetine versus placebo) employing script-driven imagery (traumatic versus neutral autobiographical memory recall). Script-elicited brain activation patterns (measured via functional magnetic resonance imagery) were analysed by means of whole-brain analyses and a pre-registered region of interest (i.e. amygdala). RESULTS Self-reported acute dissociation increased significantly during trauma (versus neutral) recall but did not differ between pharmacological conditions. The pharmacological manipulation was also unsuccessful in eliciting increased amygdala activation following script-driven imagery in the reboxetine (versus placebo) condition. In the reboxetine condition, trauma retrieval resulted in similar activation patterns as in the placebo condition (e.g. elevated brain activation in the middle occipital gyrus and supramarginal gyrus), albeit with different peaks. CONCLUSIONS Current (null) findings cast doubt on the suggested role of the amygdala in subserving dissociative processing of trauma memories. Alternative pharmacological manipulation approaches (e.g. ketamine) and analysis techniques (e.g. event-related independent component analysis) might provide better insight into the spatiotemporal dynamics and network shifts involved in dissociative experiences and autobiographical trauma memory recall.
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Affiliation(s)
- Yoki L Mertens
- Department of Clinical Psychology and Experimental Psychopathology, University of Groningen, Groningen, The Netherlands
| | - Antje Manthey
- Charité University Clinic Berlin (corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health), Berlin, Germany
| | - Anika Sierk
- Charité University Clinic Berlin (corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health), Berlin, Germany
| | - Peter de Jong
- Department of Clinical Psychology and Experimental Psychopathology, University of Groningen, Groningen, The Netherlands
| | - Henrik Walter
- Charité University Clinic Berlin (corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health), Berlin, Germany
| | - Judith K Daniels
- Department of Clinical Psychology and Experimental Psychopathology, University of Groningen, Groningen, The Netherlands
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Denny RR, Connelly KL, Ghilotti MG, Meissler JJ, Yu D, Eisenstein TK, Unterwald EM. Artificial Intelligence Identified Resilient and Vulnerable Female Rats After Traumatic Stress and Ethanol Exposure: Investigation of Neuropeptide Y Pathway Regulation. Front Neurosci 2021; 15:772946. [PMID: 34975380 PMCID: PMC8716605 DOI: 10.3389/fnins.2021.772946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022] Open
Abstract
Post-traumatic stress disorder (PTSD) is initiated by traumatic-stress exposure and manifests into a collection of symptoms including increased anxiety, sleep disturbances, enhanced response to triggers, and increased sympathetic nervous system arousal. PTSD is highly co-occurring with alcohol use disorder. Only some individuals experiencing traumatic stress develop PTSD and a subset of individuals with PTSD develop co-occurring alcohol use disorder. To investigate the basis of these individual responses to traumatic stress, single prolonged stress (SPS) a rodent model of traumatic stress was applied to young adult female rats. Individual responses to SPS were characterized by measuring anxiety-like behaviors with open field and elevated plus maze tests. Rats were then allowed to drink ethanol under an intermittent two bottle choice procedure for 8 weeks, and ethanol consumption was measured. An artificial intelligence algorithm was built to predict resilient and vulnerable individuals based on data from anxiety testing and ethanol consumption. This model was implemented in a second cohort of rats that underwent SPS without ethanol drinking to identify resilient and vulnerable individuals for further study. Analysis of neuropeptide Y (NPY) levels and expression of its receptors Y1R and Y2R mRNA in the central nucleus of the amygdala (CeA), basolateral amygdala (BLA), and bed nucleus stria terminalis (BNST) were performed. Results demonstrate that resilient rats had higher expression of Y2R mRNA in the CeA compared with vulnerable and control rats and had higher levels of NPY protein in the BNST compared to controls. The results of the study show that an artificial intelligence algorithm can identify individual differences in response to traumatic stress which can be used to predict subsequent ethanol drinking, and the NPY pathway is differentially altered following traumatic stress exposure in resilient and vulnerable populations. Understanding neurochemical alterations following traumatic-stress exposure is critical in developing prevention strategies for the vulnerable phenotype and will help further development of novel therapeutic approaches for individuals suffering from PTSD and at risk for alcohol use disorder.
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Affiliation(s)
- Ray R. Denny
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Krista L. Connelly
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Marco G. Ghilotti
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Joseph J. Meissler
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Daohai Yu
- Center for Biostatistics and Epidemiology, Department of Biomedical Education and Data Science, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Toby K. Eisenstein
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States,Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Ellen M. Unterwald
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States,Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States,*Correspondence: Ellen M. Unterwald,
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Kornhuber J, Zoicas I. Neuropeptide Y Reduces Social Fear in Male Mice: Involvement of Y1 and Y2 Receptors in the Dorsolateral Septum and Central Amygdala. Int J Mol Sci 2021; 22:10142. [PMID: 34576305 DOI: 10.3390/ijms221810142] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/16/2021] [Accepted: 09/18/2021] [Indexed: 11/17/2022] Open
Abstract
Neuropeptide Y (NPY) has anxiolytic-like effects and facilitates the extinction of cued and contextual fear in rodents. We previously showed that intracerebroventricular administration of NPY reduces the expression of social fear in a mouse model of social fear conditioning (SFC) and localized these effects to the dorsolateral septum (DLS) and central amygdala (CeA). In the present study, we aimed to identify the receptor subtypes that mediate these local effects of NPY. We show that NPY (0.1 nmol/0.2 µL/side) reduced the expression of SFC-induced social fear in a brain region- and receptor-specific manner in male mice. In the DLS, NPY reduced the expression of social fear by acting on Y2 receptors but not on Y1 receptors. As such, prior administration of the Y2 receptor antagonist BIIE0246 (0.2 nmol/0.2 μL/side) but not the Y1 receptor antagonist BIBO3304 trifluoroacetate (0.2 nmol/0.2 μL/side) blocked the effects of NPY in the DLS. In the CeA, however, BIBO3304 trifluoroacetate but not BIIE0246 blocked the effects of NPY, suggesting that NPY reduced the expression of social fear by acting on Y1 receptors but not Y2 receptors within the CeA. This study suggests that at least two distinct receptor subtypes are differentially recruited in the DLS and CeA to mediate the effects of NPY on the expression of social fear.
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Comeras LB, Hörmer N, Mohan Bethuraj P, Tasan RO. NPY Released From GABA Neurons of the Dentate Gyrus Specially Reduces Contextual Fear Without Affecting Cued or Trace Fear. Front Synaptic Neurosci 2021; 13:635726. [PMID: 34122036 PMCID: PMC8187774 DOI: 10.3389/fnsyn.2021.635726] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 04/20/2021] [Indexed: 11/15/2022] Open
Abstract
Disproportionate, maladapted, and generalized fear are essential hallmarks of posttraumatic stress disorder (PTSD), which develops upon severe trauma in a subset of exposed individuals. Among the brain areas that are processing fear memories, the hippocampal formation exerts a central role linking emotional-affective with cognitive aspects. In the hippocampus, neuronal excitability is constrained by multiple GABAergic interneurons with highly specialized functions and an extensive repertoire of co-released neuromodulators. Neuropeptide Y (NPY) is one of these co-transmitters that significantly affects hippocampal signaling, with ample evidence supporting its fundamental role in emotional, cognitive, and metabolic circuitries. Here we investigated the role of NPY in relation to GABA, both released from the same interneurons of the dorsal dentate gyrus (DG), in different aspects of fear conditioning. We demonstrated that activation of dentate GABA neurons specifically during fear recall reduced cue-related as well as trace-related freezing behavior, whereas inhibition of the same neurons had no significant effects. Interestingly, concomitant overexpression of NPY in these neurons did not further modify fear recall, neither under baseline conditions nor upon chemogenetic stimulation. However, potentially increased co-release of NPY substantially reduced contextual fear, promoted extinction learning, and long-term suppression of fear in a foreground context–conditioning paradigm. Importantly, NPY in the dorsal DG was not only expressed in somatostatin neurons, but also in parvalbumin-positive basket cells and axoaxonic cells, indicating intense feedback and feedforward modulation of hippocampal signaling and precise curtailing of neuronal engrams. Thus, these findings suggest that co-release of NPY from specific interneuron populations of the dorsal DG modifies dedicated aspects of hippocampal processing by sharpening the activation of neural engrams and the consecutive fear response. Since inappropriate and generalized fear is the major impediment in the treatment of PTSD patients, the dentate NPY system may be a suitable access point to ameliorate PTSD symptoms and improve the inherent disease course.
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Affiliation(s)
- Lucas B Comeras
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| | - Noa Hörmer
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| | | | - Ramon O Tasan
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
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Kornhuber J, Zoicas I. Brain Region-Dependent Effects of Neuropeptide Y on Conditioned Social Fear and Anxiety-Like Behavior in Male Mice. Int J Mol Sci 2021; 22:ijms22073695. [PMID: 33918123 PMCID: PMC8037261 DOI: 10.3390/ijms22073695] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 11/16/2022] Open
Abstract
Neuropeptide Y (NPY) has anxiolytic-like effects and facilitates the extinction of cued and contextual fear in rodents. We have previously shown that the intracerebroventricular administration of NPY reduces the expression of social fear in a mouse model of social fear conditioning (SFC). In the present study, we aimed to identify the brain regions that mediate these effects of NPY. We show that NPY (0.1 nmol/0.2 µL/side) reduces the expression of SFC-induced social fear in a brain-region-dependent manner. In more detail, NPY reduced the expression of social fear when administered into the dorsolateral septum (DLS) and central amygdala (CeA), but not when administered into the dorsal hippocampus (DH), medial amygdala (MeA) and basolateral amygdala (BLA). We also investigated whether the reduced expression of social fear might partly be due to a reduced anxiety-like behavior, and showed that NPY exerted anxiolytic-like effects when administered into the DH, DLS, CeA and BLA, but not when administered into the MeA. This study identifies the DLS and the CeA as brain regions mediating the effects of NPY on the expression of social fear and suggests that partly distinct neural circuitries mediate the effects of NPY on the expression of social fear and on anxiety-like behavior.
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Bartsch JC, Jamil S, Remmes J, Verma D, Pape HC. Functional deletion of neuropeptide Y receptors type 2 in local synaptic networks of anteroventral BNST facilitates recall and increases return of fear. Mol Psychiatry 2021; 26:2900-11. [PMID: 32709995 DOI: 10.1038/s41380-020-0846-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 07/06/2020] [Accepted: 07/13/2020] [Indexed: 12/14/2022]
Abstract
Return of previously extinguished fear memories presents a major hurdle in treatment of fear-related disorders. Neuropeptide Y receptors type 2 (Y2R) in the bed nucleus of stria terminalis (BNST) seem to play a crucial role in modulation of remote fear memories. Here, we targeted Cre-channelrhodopsin-2 to defined subregions of BNST or central amygdala (CeA) in floxed Y2R mice (Y2lox/lox) for functional deletion of Y2R. We combined fear training and behavioral studies in vivo with optogenetic-electrophysiological analysis of BNST synaptic network activity ex vivo, in order to identify regional and cellular specificities of Y2R influence. Deletion of Y2R in the ventral section of anterior BNST (BNSTav) did not affect fear acquisition, but increased conditioned fear during recall and extinction learning, and aggravated remote fear return. By contrast, deletion of Y2R in the dorsal section of anterior BNST (BNSTad) or CeA did not influence acquisition, extinction or return of fear memories. Ex vivo optogenetic-electrophysiological analysis revealed Y2R-expressing local GABAergic inhibitory networks in BNST, both within (intraregional) and in-between (inter-regional) BNST subregions. Stimulation of Y2R resulted in a presynaptically mediated reduction of GABAergic responses, which did not differ between intraregional but predominantly affected inter-regional connections from BNSTav to BNSTad. Moreover, deletion of Y2R decreased the excitation/inhibition balance in BNSTav neurons, suggesting a regulatory influence of endogenous NPY via intraregional GABAergic microcircuits. This study reveals Y2R within local GABAergic networks in BNST as key elements in facilitating extinction and reducing return of remote fear memories, suggesting a potential avenue for translational purposes.
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Lach G, Fülling C, Bastiaanssen TFS, Fouhy F, Donovan ANO, Ventura-Silva AP, Stanton C, Dinan TG, Cryan JF. Enduring neurobehavioral effects induced by microbiota depletion during the adolescent period. Transl Psychiatry 2020; 10:382. [PMID: 33159036 PMCID: PMC7648059 DOI: 10.1038/s41398-020-01073-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/15/2020] [Accepted: 10/05/2020] [Indexed: 12/20/2022] Open
Abstract
The gut microbiota is an essential regulator of many aspects of host physiology. Disruption of gut microbial communities affects gut-brain communication which ultimately can manifest as changes in brain function and behaviour. Transient changes in gut microbial composition can be induced by various intrinsic and extrinsic factors, however, it is possible that enduring shifts in the microbiota composition can be achieved by perturbation at a timepoint when the gut microbiota has not fully matured or is generally unstable, such as during early life or ageing. In this study, we investigated the effects of 3-week microbiota depletion with antibiotic treatment during the adolescent period and in adulthood. Following a washout period to restore the gut microbiota, behavioural and molecular hallmarks of gut-brain communication were investigated. Our data revealed that transient microbiota depletion had long-lasting effects on microbiota composition and increased anxiety-like behaviour in mice exposed to antibiotic treatment during adolescence but not in adulthood. Similarly, gene expression in the amygdala was more severely affected in mice treated during adolescence. Taken together these data highlight the vulnerability of the gut microbiota during the critical adolescent period and the long-lasting impact manipulations of the microbiota can have on gene expression and behaviour in adulthood.
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Affiliation(s)
- Gilliard Lach
- grid.7872.a0000000123318773APC Microbiome Ireland, University College Cork, Cork, Ireland ,grid.4305.20000 0004 1936 7988Present Address: University of Edinburgh, Edinburgh, Scotland UK
| | - Christine Fülling
- grid.7872.a0000000123318773APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Thomaz F. S. Bastiaanssen
- grid.7872.a0000000123318773APC Microbiome Ireland, University College Cork, Cork, Ireland ,grid.7872.a0000000123318773Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Fiona Fouhy
- grid.7872.a0000000123318773APC Microbiome Ireland, University College Cork, Cork, Ireland ,grid.6435.40000 0001 1512 9569Teagasc Food Research Centre, Food Biosciences Department, Moorepark, Fermoy, Ireland
| | - Aoife N. O’ Donovan
- grid.7872.a0000000123318773APC Microbiome Ireland, University College Cork, Cork, Ireland ,grid.6435.40000 0001 1512 9569Teagasc Food Research Centre, Food Biosciences Department, Moorepark, Fermoy, Ireland ,grid.7872.a0000000123318773School of Microbiology, University College Cork, Cork, Ireland
| | | | - Catherine Stanton
- grid.7872.a0000000123318773APC Microbiome Ireland, University College Cork, Cork, Ireland ,grid.6435.40000 0001 1512 9569Teagasc Food Research Centre, Food Biosciences Department, Moorepark, Fermoy, Ireland
| | - Timothy G. Dinan
- grid.7872.a0000000123318773APC Microbiome Ireland, University College Cork, Cork, Ireland ,grid.7872.a0000000123318773Department of Psychiatry and Neurobehavioural Sciences, University College Cork, Cork, Ireland
| | - John F. Cryan
- grid.7872.a0000000123318773APC Microbiome Ireland, University College Cork, Cork, Ireland ,grid.7872.a0000000123318773Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
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Nwokafor C, Serova LI, Nahvi RJ, McCloskey J, Sabban EL. Activation of NPY receptor subtype 1 by [D-His 26]NPY is sufficient to prevent development of anxiety and depressive like effects in the single prolonged stress rodent model of PTSD. Neuropeptides 2020; 80:102001. [PMID: 31916978 DOI: 10.1016/j.npep.2019.102001] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/17/2019] [Accepted: 12/20/2019] [Indexed: 12/18/2022]
Abstract
The neuropeptide Y (NPY) system plays an important role in mediating resilience to the harmful effect of stress in post-traumatic stress disorder (PTSD). It can mediate its effects via several G-protein coupled receptors: Y1R, Y2R, Y4R and Y5R. To investigate the role of individual NPY receptors in the resilience effects of NPY to traumatic stress, intranasal infusion of either Y1R agonists [D-His26]NPY, [Leu31Pro34]NPY, Y2R agonist NPY (3-36) or NPY were administered to male Sprague-Dawley rats immediately following the last stressor of the single prolonged stress (SPS) protocol, a widely used PTSD animal model. After 7 or 14 days, effects of the treatments were measured on the elevated plus maze (EPM) for anxiety, in forced swim test (FST) for development of depressive-like or re-experiencing behavior, in social interaction (SI) test for impaired social behavior, and acoustic startle response (ASR) for hyperarousal. [D-His26]NPY, but not [Leu31Pro34]NPY nor NPY (3-36) Y2R, was effective in preventing the SPS-elicited development of anxiety. Y1R, but not Y2R agonists prevented development of depressive- feature on FST, with [D-His26]NPY superior to NPY. The results demonstrate that [D-His26]NPY was sufficient to prevent development of anxiety, social impairment and depressive symptoms, and has promise as an early intervention therapy following traumatic stress.
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Affiliation(s)
- Chiso Nwokafor
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - Lidia I Serova
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - Roxanna J Nahvi
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - Jaclyn McCloskey
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
| | - Esther L Sabban
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
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12
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Abstract
BACKGROUND Neuropeptide Y (NPY) has anxiolytic effects and facilitates extinction of cued and contextual fear in rodents, thereby acting as a resilience factor against exaggerated fear responses after adverse events. We investigated whether NPY influences acquisition, expression and extinction of social fear in a mouse model of social fear conditioning (SFC). METHODS NPY was administered intracerebroventricularly before SFC or before social fear extinction with or without prior administration of Y1 and/or Y2 receptor antagonists. RESULTS We show that NPY affects SFC-induced social fear in a time point-dependent manner. When administered before SFC, NPY did not affect acquisition, expression and extinction of social fear. However, when administered before social fear extinction, NPY reduced expression of social fear via simultaneous activation of Y1 and Y2 receptors. As such, neither the Y1 receptor antagonist BIBO3304 trifluoroacetate nor the Y2 receptor antagonist BIIE0246 was able to block the effects of NPY completely. However, when administered in combination, they completely blocked the effects of NPY on social fear expression. CONCLUSIONS These findings have important clinical implications, as they suggest that although medication strategies aimed at increasing brain NPY activity are unlikely to prevent the formation of aversive memories after a traumatic social experience, they might improve the recovery from a traumatic social experience by reducing the expression of social fear.
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Affiliation(s)
| | - Iulia Zoicas
- Iulia Zoicas, Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University Erlangen-Nürnberg, Schwabachanlage 6, Erlangen 91054, Germany.
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13
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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: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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14
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Hörmer BA, Verma D, Gasser E, Wieselthaler-hölzl A, Herzog H, Tasan RO. Hippocampal NPY Y2 receptors modulate memory depending on emotional valence and time. Neuropharmacology 2018; 143:20-8. [DOI: 10.1016/j.neuropharm.2018.09.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/29/2018] [Accepted: 09/11/2018] [Indexed: 12/13/2022]
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15
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Verma D, Tasan R, Sperk G, Pape HC. Neuropeptide Y2 receptors in anteroventral BNST control remote fear memory depending on extinction training. Neurobiol Learn Mem 2018; 149:144-153. [PMID: 29408468 DOI: 10.1016/j.nlm.2018.01.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 12/15/2017] [Accepted: 01/23/2018] [Indexed: 12/12/2022]
Abstract
The anterior bed nucleus of stria terminalis (BNST) is involved in reinstatement of extinguished fear, and neuropeptide Y2 receptors influence local synaptic signaling. Therefore, we hypothesized that Y2 receptors in anteroventral BNST (BNSTav) interfere with remote fear memory and that previous fear extinction is an important variable. C57BL/6NCrl mice were fear-conditioned, and a Y2 receptor-specific agonist (NPY3-36) or antagonist (JNJ-5207787) was applied in BNSTav before fear retrieval at the following day. Remote fear memory was tested on day 16 in two groups of mice, which had (experiment 1) or had not (experiment 2) undergone extinction training after conditioning. In the group with extinction training, tests of remote fear memory revealed partial retrieval of extinction, which was prevented after blockade of Y2 receptors in BNSTav. No such effect was observed in the group with no extinction training, but stimulation of Y2 receptors in BNSTav mimicked the influence of extinction during tests of remote fear memory. Pharmacological manipulation of Y2 receptors in BNSTav before fear acquisition (experiment 3) had no effect on fear memory retrieval, extinction or remote fear memory. Furthermore, partial retrieval of extinction during tests of remote fear memory was associated with changes in number of c-Fos expressing neurons in BNSTav, which was prevented or mimicked upon Y2 blockade or stimulation in BNSTav. These results indicate that Y2 receptor manipulation in BNSTav interferes with fear memory and extinction retrieval at remote stages, likely through controlling neuronal activity in BNSTav during extinction training.
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Affiliation(s)
- Dilip Verma
- Institute of Physiology 1, Westfälische Wilhelms-University, D-48149 Münster, Germany
| | - Ramon Tasan
- Institute of Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Guenther Sperk
- Institute of Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Hans-Christian Pape
- Institute of Physiology 1, Westfälische Wilhelms-University, D-48149 Münster, Germany.
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16
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Kautz M, Charney DS, Murrough JW. Neuropeptide Y, resilience, and PTSD therapeutics. Neurosci Lett 2017; 649:164-9. [PMID: 27913193 DOI: 10.1016/j.neulet.2016.11.061] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/22/2016] [Accepted: 11/28/2016] [Indexed: 11/20/2022]
Abstract
Resilience to traumatic stress is a complex psychobiological process that protects individuals from developing posttraumatic stress disorder (PTSD) or other untoward consequences of exposure to extreme stress, including depression. Progress in translational research points toward the neuropeptide Y (NPY) system - among others - as a key mediator of stress response and as a potential therapeutic focus for PTSD. Substantial preclinical evidence supports the role of NPY in the modulation of stress response and in the regulation of anxiety in animal models. Clinical studies testing the safety and efficacy of modulating the NPY system in humans, however, have lagged behind. In the current article, we review the evidence base for targeting the NPY system as a therapeutic approach in PTSD, and consider impediments and potential solutions to therapeutic development.
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17
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Schmeltzer SN, Herman JP, Sah R. Neuropeptide Y (NPY) and posttraumatic stress disorder (PTSD): A translational update. Exp Neurol 2016; 284:196-210. [PMID: 27377319 PMCID: PMC8375392 DOI: 10.1016/j.expneurol.2016.06.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 06/15/2016] [Accepted: 06/20/2016] [Indexed: 12/12/2022]
Abstract
Posttraumatic stress disorder (PTSD) is a trauma-evoked syndrome, with variable prevalence within the human population due to individual differences in coping and resiliency. In this review, we discuss evidence supporting the relevance of neuropeptide Y (NPY), a stress regulatory transmitter in PTSD. We consolidate findings from preclinical, clinical, and translational studies of NPY that are of relevance to PTSD with an attempt to provide a current update of this area of research. NPY is abundantly expressed in forebrain limbic and brainstem areas that regulate stress and emotional behaviors. Studies in rodents demonstrate a role for NPY in stress responses, anxiety, fear, and autonomic regulation, all relevant to PTSD symptomology. Genetic studies support an association of NPY polymorphisms with stress coping and affect. Importantly, cerebrospinal fluid (CSF) measurements in combat veterans provide direct evidence of NPY association with PTSD diagnosis and symptomology. In addition, NPY involvement in pain, depression, addiction, and metabolism may be relevant to comorbidities associated with PTSD. Collectively, the literature supports the relevance of NPY to PTSD pathophysiology, although knowledge gaps remain. The NPY system is an attractive target in terms of understanding the physiological basis of PTSD as well as treatment of the disorder.
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Affiliation(s)
- Sarah N Schmeltzer
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH 45237, United States
| | - James P Herman
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH 45237, United States
| | - Renu Sah
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH 45237, United States; VA Medical Center, Cincinnati, OH, 45220, United States.
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18
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Lach G, Bicca MA, Hoeller AA, Santos ECDS, Costa APR, de Lima TCM. Short-term enriched environment exposure facilitates fear extinction in adult rats: The NPY-Y1 receptor modulation. Neuropeptides 2016; 55:73-8. [PMID: 26490304 DOI: 10.1016/j.npep.2015.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 09/30/2015] [Accepted: 10/01/2015] [Indexed: 12/14/2022]
Abstract
Neuropeptides have an important role in several psychiatric conditions. Among them, neuropeptide Y (NPY) seems to be essential to modulate some features of stress-related disorders. Post-traumatic stress disorder (PTSD), characterized by inappropriate fear generalization to safe situations may be modulated by NPY manipulation since this neuropeptide is involved in the promotion of coping with stress. Experimentally, coping strategies have been obtained after exposure in enriched environment (EE) rather than standard one. Thus, in the present study we aimed to assess whether short-term EE situation and NPY-Y1 receptor (Y1r) modulation may affect the extinction of contextual fear conditioning, an experimental approach to PTSD. Here we show that EE-rats have the contextual fear extinction facilitated, and this facilitation was reverted by central infusion of BIBO3304, a nonpeptide Y1r antagonist. In addition, protein analysis revealed an upregulation of hippocampal Y1r in conditioned EE-rats, but no changes were observed in EE-rats that were not conditioned. Our results demonstrated that protective properties of EE on fear extinction can be regulated, at least in part, by activation of NPY-signaling through Y1r within hippocampus, an area that plays a major role in contextual memories. Overall, the activation of Y1r is important to promote better and faster perception of self-location (context), and to reduce fear generalization in rats exposed to EE.
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Affiliation(s)
- Gilliard Lach
- Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC 88049-900, Brazil.
| | - Maira Assunção Bicca
- Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC 88049-900, Brazil
| | - Alexandre Ademar Hoeller
- Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC 88049-900, Brazil; Postgraduate Program in Medical Science, Center of Health Sciences, University Hospital, Federal University of Santa Catarina, Florianópolis, SC 88040-970, Brazil
| | - Evelyn Cristina da Silva Santos
- Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC 88049-900, Brazil
| | - Ana Paula Ramos Costa
- Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC 88049-900, Brazil
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19
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Tasan RO, Verma D, Wood J, Lach G, Hörmer B, de Lima TCM, Herzog H, Sperk G. The role of Neuropeptide Y in fear conditioning and extinction. Neuropeptides 2016; 55:111-26. [PMID: 26444585 DOI: 10.1016/j.npep.2015.09.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/10/2015] [Accepted: 09/10/2015] [Indexed: 12/23/2022]
Abstract
While anxiety disorders are the brain disorders with the highest prevalence and constitute a major burden for society, a considerable number of affected people are still treated insufficiently. Thus, in an attempt to identify potential new anxiolytic drug targets, neuropeptides have gained considerable attention in recent years. Compared to classical neurotransmitters they often have a regionally restricted distribution and may bind to several distinct receptor subtypes. Neuropeptide Y (NPY) is a highly conserved neuropeptide that is specifically concentrated in limbic brain areas and signals via at least 5 different G-protein-coupled receptors. It is involved in a variety of physiological processes including the modulation of emotional-affective behaviors. An anxiolytic and stress-reducing property of NPY is supported by many preclinical studies. Whether NPY may also interact with processing of learned fear and fear extinction is comparatively unknown. However, this has considerable relevance since pathological, inappropriate and generalized fear expression and impaired fear extinction are hallmarks of human post-traumatic stress disorder and a major reason for its treatment-resistance. Recent evidence from different laboratories emphasizes a fear-reducing role of NPY, predominantly mediated by exogenous NPY acting on Y1 receptors. Since a reduction of fear expression was also observed in Y1 receptor knockout mice, other Y receptors may be equally important. By acting on Y2 receptors, NPY promotes fear extinction and generates a long-term suppression of fear, two important preconditions that could support cognitive behavioral therapies in human patients. A similar effect has been demonstrated for the closely related pancreatic polypeptide (PP) when acting on Y4 receptors. Preliminary evidence suggests that NPY modulates fear in particular by activation of Y1 and Y2 receptors in the basolateral and central amygdala, respectively. In the basolateral amygdala, NPY signaling activates inhibitory G protein-coupled inwardly-rectifying potassium channels or suppresses hyperpolarization-induced I(h) currents in a Y1 receptor-dependent fashion, favoring a general suppression of neuronal activity. A more complex situation has been described for the central extended amygdala, where NPY reduces the frequency of inhibitory and excitatory postsynaptic currents. In particular the inhibition of long-range central amygdala output neurons may result in a Y2 receptor-dependent suppression of fear. The role of NPY in processes of learned fear and fear extinction is, however, only beginning to emerge, and multiple questions regarding the relevance of endogenous NPY and different receptor subtypes remain elusive. Y2 receptors may be of particular interest for future studies, since they are the most prominent Y receptor subtype in the human brain and thus among the most promising therapeutic drug targets when translating preclinical evidence to potential new therapies for human anxiety disorders.
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Affiliation(s)
- R O Tasan
- Department of Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria.
| | - D Verma
- Institute of Physiology I, University of Münster, D-48149 Münster, Germany
| | - J Wood
- Department of Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - G Lach
- Department of Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria; Capes Foundation, Ministry of Education of Brazil, 70040-020 Brasília/DF, Brazil
| | - B Hörmer
- Department of Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - T C M de Lima
- Department of Pharmacology, Federal University of Santa Catarina, 88049-970 Florianópolis, Brazil
| | - H Herzog
- Neuroscience Research Program, Garvan Institute of Medical Research, Darlinghurst, Sydney, NSW 2010, Australia
| | - G Sperk
- Department of Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria
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Vollmer LL, Schmeltzer S, Schurdak J, Ahlbrand R, Rush J, Dolgas CM, Baccei ML, Sah R. Neuropeptide Y Impairs Retrieval of Extinguished Fear and Modulates Excitability of Neurons in the Infralimbic Prefrontal Cortex. J Neurosci 2016; 36:1306-15. [PMID: 26818517 PMCID: PMC6604823 DOI: 10.1523/jneurosci.4955-13.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 11/23/2015] [Accepted: 12/16/2015] [Indexed: 11/21/2022] Open
Abstract
Neuropeptide Y (NPY), a 36 aa peptide, regulates stress and emotional behaviors. Preclinical and clinical studies support an association of NPY with trauma-evoked syndromes such as posttraumatic stress disorder (PTSD), although the exact contribution of NPY is not clear. In the current study, we examined functional attributes of NPY in the infralimbic (IL) cortex, an area that regulates fear memories and is reported to be hypoactive in PTSD. Carriers of NPY gene polymorphism rs16147 have been reported to have elevated prefrontal NPY expression. Infusion of NPY into the IL cortex in rats significantly impaired fear extinction memory without affecting conditioned fear expression or acquisition of extinction. Neuroendocrine stress response, depression-like behavior, and working memory performance were not affected by NPY infusion into the IL. The NPY Y1 receptor antagonist BIBO3304 completely abolished NPY effects on fear extinction retrieval. Y1 receptor expression was localized on CaMKII-positive pyramidal projection neurons and GAD67-positive interneurons in the IL. Patch-clamp recordings revealed increased inhibitory synaptic transmission onto IL projection neurons in the presence of NPY. Thus, NPY dampens excitability of IL projection neurons and impairs retrieval of extinction memory by inhibiting consolidation of extinction. Of relevance to PTSD, elevation of prefrontal NPY attributable to the genetic polymorphism rs16147 may contribute to IL hypoactivity, resulting in impaired extinction memory and susceptibility to the disorder. SIGNIFICANCE STATEMENT Neuropeptide Y (NPY), a stress modulatory transmitter, is associated with posttraumatic stress disorder (PTSD). Contribution of NPY to PTSD symptomology is unclear. PTSD patients have reduced activity in the infralimbic (IL) subdivision of the medial prefrontal cortex (mPFC), associated with compromised extinction memory. No information exists on fear modulation by NPY in the IL cortex, although NPY and NPY receptors are abundant in these areas. This study shows that IL NPY inhibits consolidation of extinction, resulting in impaired retrieval of extinction memory and modulates excitability of IL projection neurons. In addition to providing a novel perspective on extinction memory modulation by NPY, our findings suggest that elevated mPFC NPY in gene polymorphism rs16147 carriers or after chronic stress could increase susceptibility to PTSD.
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Affiliation(s)
- Lauren L Vollmer
- Departments of Psychiatry and Behavioral Neuroscience and Neuroscience Graduate Program, University of Cincinnati, Cincinnati, Ohio 45221, and
| | - Sarah Schmeltzer
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, Ohio 45221, and
| | | | | | - Jennifer Rush
- Departments of Psychiatry and Behavioral Neuroscience and
| | | | - Mark L Baccei
- Anesthesiology and Neuroscience Graduate Program, University of Cincinnati, Cincinnati, Ohio 45221, and
| | - Renu Sah
- Departments of Psychiatry and Behavioral Neuroscience and Neuroscience Graduate Program, University of Cincinnati, Cincinnati, Ohio 45221, and Veterans Administration Medical Center, Cincinnati, Ohio 45220
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Stockhorst U, Antov MI. Modulation of Fear Extinction by Stress, Stress Hormones and Estradiol: A Review. Front Behav Neurosci 2016; 9:359. [PMID: 26858616 PMCID: PMC4726806 DOI: 10.3389/fnbeh.2015.00359] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/14/2015] [Indexed: 12/25/2022] Open
Abstract
Fear acquisition and extinction are valid models for the etiology and treatment of anxiety, trauma- and stressor-related disorders. These disorders are assumed to involve aversive learning under acute and/or chronic stress. Importantly, fear conditioning and stress share common neuronal circuits. The stress response involves multiple changes interacting in a time-dependent manner: (a) the fast first-wave stress response [with central actions of noradrenaline, dopamine, serotonin, corticotropin-releasing hormone (CRH), plus increased sympathetic tone and peripheral catecholamine release] and (b) the second-wave stress response [with peripheral release of glucocorticoids (GCs) after activation of the hypothalamus-pituitary-adrenocortical (HPA) axis]. Control of fear during extinction is also sensitive to these stress-response mediators. In the present review, we will thus examine current animal and human data, addressing the role of stress and single stress-response mediators for successful acquisition, consolidation and recall of fear extinction. We report studies using pharmacological manipulations targeting a number of stress-related neurotransmitters and neuromodulators [monoamines, opioids, endocannabinoids (eCBs), neuropeptide Y, oxytocin, GCs] and behavioral stress induction. As anxiety, trauma- and stressor-related disorders are more common in women, recent research focuses on female sex hormones and identifies a potential role for estradiol in fear extinction. We will thus summarize animal and human data on the role of estradiol and explore possible interactions with stress or stress-response mediators in extinction. This also aims at identifying time-windows of enhanced (or reduced) sensitivity for fear extinction, and thus also for successful exposure therapy.
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Affiliation(s)
- Ursula Stockhorst
- Experimental Psychology II and Biological Psychology, Institute of Psychology, University of OsnabrückOsnabrück, Germany
| | - Martin I. Antov
- Experimental Psychology II and Biological Psychology, Institute of Psychology, University of OsnabrückOsnabrück, Germany
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