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Brown A, Chaudhri N. Optogenetic stimulation of infralimbic cortex projections to the paraventricular thalamus attenuates context-induced renewal. Eur J Neurosci 2023; 57:762-779. [PMID: 36373226 DOI: 10.1111/ejn.15862] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 10/11/2022] [Accepted: 10/27/2022] [Indexed: 11/16/2022]
Abstract
Contexts associated with prior reinforcement can renew extinguished conditioned responding. The prelimbic (PL) and infralimbic (IL) cortices are thought to mediate the expression and suppression of conditioned responding, respectively. Evidence suggests that PL inputs to the paraventricular nucleus of the thalamus (PVT) drive the expression of cue-induced reinstatement of drug seeking and that IL inputs to the PVT mediate fear extinction retrieval. However, the role of these projections in renewal of appetitive Pavlovian conditioned responding is unknown. We trained male and female Long-Evans rats to associate a conditioned stimulus (CS; 10 s white noise) with delivery of a 10% sucrose unconditioned stimulus (US; .2 ml/CS) to a fluid port in a distinct context (Context A). We then extinguished responding by presenting the CS without the US in a different context (Context B). At test, rats were returned to Context A, and optogenetic stimulation was delivered to either the IL-to-PVT or PL-to-PVT pathway during CS presentations. Optically stimulating the IL-to-PVT, but not the PL-to-PVT pathway, attenuated ABA renewal of CS port entries, and this effect was similar in males and females. Further, rats self-administered optical stimulation of the IL-to-PVT but not the PL-to-PVT pathway suggesting that activation of the IL-to-PVT pathway is reinforcing. The effectiveness of optical stimulation parameters to activate neurons in the IL, PL and PVT was confirmed using Fos immunohistochemistry. These findings provide evidence for novel neural mechanisms in renewal of responding to a sucrose-predictive CS, as well as more generally in contextual processing and appetitive associative learning.
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Affiliation(s)
- Alexa Brown
- Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia University, Montreal, Quebec, Canada
| | - Nadia Chaudhri
- Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia University, Montreal, Quebec, Canada
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Brown A, Villaruel FR, Chaudhri N. Neural correlates of recall and extinction in a rat model of appetitive Pavlovian conditioning. Behav Brain Res 2023; 440:114248. [PMID: 36496079 DOI: 10.1016/j.bbr.2022.114248] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/30/2022] [Accepted: 12/04/2022] [Indexed: 12/12/2022]
Abstract
Extinction is a fundamental form of inhibitory learning that is important for adapting to changing environmental contingencies. While numerous studies have investigated the neural correlates of extinction using Pavlovian fear conditioning and appetitive operant reward-seeking procedures, less is known about the neural circuitry mediating the extinction of appetitive Pavlovian responding. Here, we aimed to generate an extensive brain activation map of extinction learning in a rat model of appetitive Pavlovian conditioning. Male Long-Evans rats were trained to associate a conditioned stimulus (CS; 20 s white noise) with the delivery of a 10% sucrose unconditioned stimulus (US; 0.3 ml/CS) to a fluid port. Control groups also received CS presentations, but sucrose was delivered either during the inter-trial interval or in the home-cage. After conditioning, 1 or 6 extinction sessions were conducted in which the CS was presented but sucrose was withheld. We performed Fos immunohistochemistry and network connectivity analyses on a set of cortical, striatal, thalamic, and amygdalar brain regions. Neural activity in the prelimbic cortex, ventral orbitofrontal cortex, nucleus accumbens core, and paraventricular nucleus of the thalamus was greater during recall relative to extinction. Conversely, prolonged extinction following 6 sessions induced increased neural activity in the infralimbic cortex, medial orbitofrontal cortex, and nucleus accumbens shell compared to home-cage controls. All these structures were similarly recruited during recall on the first extinction session. These findings provide novel evidence for the contribution of brain areas and neural networks that are differentially involved in the recall versus extinction of appetitive Pavlovian conditioned responding.
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Affiliation(s)
- Alexa Brown
- Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia University, Montreal, QC, Canada.
| | - Franz R Villaruel
- Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia University, Montreal, QC, Canada
| | - Nadia Chaudhri
- Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia University, Montreal, QC, Canada
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Hartsock MJ, Brennan NA, Spencer RL. Circadian Rhythms in Fear Extinction Recall Depend on the Time of Day of Extinction Recall, Not the Time of Day of Extinction Learning. J Biol Rhythms 2023; 38:109-115. [PMID: 36281735 DOI: 10.1177/07487304221128161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The recall of conditioned fear extinction exhibits a circadian rhythm in humans and rodents, with optimal extinction recall occurring during the early active phase. However, it remains unclear whether this rhythm depends on the circadian modulation of mechanisms supporting memory consolidation versus memory maintenance and retrieval. Here, adult male rats underwent conditioned fear extinction at one of four times throughout the day and then, starting 24 h after extinction, were repeatedly tested for extinction recall over the next 24 h. Rats undergoing extinction learning during the early active phase tended toward accelerated extinction learning compared with rats in other groups, pointing to rhythms in mechanisms that support extinction memory encoding. The next day, the strength of extinction recall followed a 24-h cycle that depended not on the time of day of extinction learning but, instead, on the time of day of extinction recall. This latter finding indicates a rhythm in mechanisms supporting extinction memory maintenance and/or retrieval. Subsequent testing for fear relapse in the conditioning context suggested reduced fear in rats tested during the early active phase. These results lay the groundwork for mechanistic investigations of circadian rhythms in fear extinction memory.
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Affiliation(s)
- Matthew J Hartsock
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado
| | - Nicholas A Brennan
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado
| | - Robert L Spencer
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado
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54
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Diehl GW, Redish AD. Differential processing of decision information in subregions of rodent medial prefrontal cortex. eLife 2023; 12:82833. [PMID: 36652289 PMCID: PMC9848391 DOI: 10.7554/elife.82833] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 01/05/2023] [Indexed: 01/19/2023] Open
Abstract
Decision-making involves multiple cognitive processes requiring different aspects of information about the situation at hand. The rodent medial prefrontal cortex (mPFC) has been hypothesized to be central to these abilities. Functional studies have sought to link specific processes to specific anatomical subregions, but past studies of mPFC have yielded controversial results, leaving the precise nature of mPFC function unclear. To settle this debate, we recorded from the full dorso-ventral extent of mPFC in each of 8 rats, as they performed a complex economic decision task. These data revealed four distinct functional domains within mPFC that closely mirrored anatomically identified subregions, including novel evidence to divide prelimbic cortex into dorsal and ventral components. We found that dorsal aspects of mPFC (ACC, dPL) were more involved in processing information about active decisions, while ventral aspects (vPL, IL) were more engaged in motivational factors.
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Affiliation(s)
- Geoffrey W Diehl
- Department of Neuroscience, University of MinnesotaMinneapolisUnited States
| | - A David Redish
- Department of Neuroscience, University of MinnesotaMinneapolisUnited States
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55
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Gorkiewicz T, Danielewski K, Andraka K, Kondrakiewicz K, Meyza K, Kaminski J, Knapska E. Social buffering diminishes fear response but does not equal improved fear extinction. Cereb Cortex 2022; 33:5007-5024. [PMID: 36218820 PMCID: PMC10110450 DOI: 10.1093/cercor/bhac395] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 09/02/2022] [Accepted: 09/03/2022] [Indexed: 11/15/2022] Open
Abstract
Social support during exposure-based psychotherapy is believed to diminish fear and improve therapy outcomes. However, some clinical trials challenge that notion. Underlying mechanisms remain unknown, hindering the understanding of benefits and pitfalls of such approach. To study social buffering during fear extinction, we developed a behavioral model in which partner's presence decreases response to fear-associated stimuli. To identify the neuronal background of this phenomenon, we combined behavioral testing with c-Fos mapping, optogenetics, and chemogenetics. We found that the presence of a partner during fear extinction training causes robust inhibition of freezing; the effect, however, disappears in subjects tested individually on the following day. It is accompanied by lowered activation of the prelimbic (PL) and anterior cingulate (ACC) but not infralimbic (IL) cortex. Accordingly, blocking of IL activity left social buffering intact. Similarly, inhibition of the ventral hippocampus-PL pathway, suppressing fear response after prolonged extinction training, did not diminish the effect. In contrast, inhibition of the ACC-central amygdala pathway, modulating social behavior, blocked social buffering. By reporting that social modulation of fear inhibition is transient and insensitive to manipulation of the fear extinction-related circuits, we show that the mechanisms underlying social buffering during extinction are different from those of individual extinction.
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Affiliation(s)
- Tomasz Gorkiewicz
- Neurobiology of Emotions Laboratory, Nencki-EMBL Partnership for Neural Plasticity and Brain Disorders - BRAINCITY, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Konrad Danielewski
- Neurobiology of Emotions Laboratory, Nencki-EMBL Partnership for Neural Plasticity and Brain Disorders - BRAINCITY, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Karolina Andraka
- Neurobiology of Emotions Laboratory, Nencki-EMBL Partnership for Neural Plasticity and Brain Disorders - BRAINCITY, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Kacper Kondrakiewicz
- Neurobiology of Emotions Laboratory, Nencki-EMBL Partnership for Neural Plasticity and Brain Disorders - BRAINCITY, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland.,NeuroElectronics Research Flanders, Leuven, Belgium
| | - Ksenia Meyza
- Neurobiology of Emotions Laboratory, Nencki-EMBL Partnership for Neural Plasticity and Brain Disorders - BRAINCITY, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Jan Kaminski
- Neurophysiology of Mind Laboratory, Nencki-EMBL Partnership for Neural Plasticity and Brain Disorders - BRAINCITY, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Ewelina Knapska
- Neurobiology of Emotions Laboratory, Nencki-EMBL Partnership for Neural Plasticity and Brain Disorders - BRAINCITY, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
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56
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Souza RR, Powers MB, Rennaker RL, McIntyre CK, Hays SA, Kilgard MP. Timing of vagus nerve stimulation during fear extinction determines efficacy in a rat model of PTSD. Sci Rep 2022; 12:16526. [PMID: 36192564 PMCID: PMC9530175 DOI: 10.1038/s41598-022-20301-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 09/12/2022] [Indexed: 11/09/2022] Open
Abstract
Studies have indicated that vagus nerve stimulation (VNS) enhances extinction learning in rodent models. Here, we investigated if pairing VNS with the conditioned stimulus is required for the enhancing effects of VNS. Adult Sprague-Dawley rats were exposed to intense stress followed by fear conditioning training to produce resistant fear. Rats were then implanted with a cuff electrode around the left vagus. After recovery, rats underwent extinction training paired with VNS (0.5 s, 0.8 mA, 100 µs, and 30 Hz) or with Sham VNS (0 mA). VNS rats were randomized into the following subgroups: During VNS (delivered during presentations of the conditioned stimulus, CS), Between VNS (delivered between CS presentations), Continuous VNS (delivered during the entire extinction session), and Dispersed VNS (delivered at longer inter-stimulation intervals across the extinction session). Sham VNS rats failed to extinguish the conditioned fear response over 5 days of repeated exposure to the CS. Rats that received Between or Dispersed VNS showed modest improvement in conditioned fear at the retention test. During and Continuous VNS groups displayed the greatest reduction in conditioned fear. These findings indicate that delivering VNS paired precisely with CS presentations or continuously throughout extinction promotes the maximum enhancement in extinction learning.
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Affiliation(s)
- Rimenez R Souza
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, 75080, USA.
- School of Behavioral Brain Sciences, The University of Texas at Dallas, Bioengineering and Sciences Building, 14.506, 800 West Campbell Road, Richardson, TX, 75080, USA.
| | - Mark B Powers
- Baylor University Medical Center, Dallas, TX, 75246, USA
| | - Robert L Rennaker
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, 75080, USA
- School of Behavioral Brain Sciences, The University of Texas at Dallas, Bioengineering and Sciences Building, 14.506, 800 West Campbell Road, Richardson, TX, 75080, USA
- Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Christa K McIntyre
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, 75080, USA
- School of Behavioral Brain Sciences, The University of Texas at Dallas, Bioengineering and Sciences Building, 14.506, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Seth A Hays
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, 75080, USA
- Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Michael P Kilgard
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, 75080, USA
- School of Behavioral Brain Sciences, The University of Texas at Dallas, Bioengineering and Sciences Building, 14.506, 800 West Campbell Road, Richardson, TX, 75080, USA
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57
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Nishimura KJ, Poulos A, Drew MR, Rajbhandari AK. Know thy SEFL: Fear sensitization and its relevance to stressor-related disorders. Neurosci Biobehav Rev 2022; 142:104884. [PMID: 36174795 DOI: 10.1016/j.neubiorev.2022.104884] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/07/2022] [Accepted: 09/17/2022] [Indexed: 11/27/2022]
Abstract
Extreme stress can cause long-lasting changes in affective behavior manifesting in conditions such as post-traumatic stress disorder (PTSD). Understanding the biological mechanisms that govern trauma-induced behavioral dysregulation requires reliable and rigorous pre-clinical models that recapitulate multiple facets of this complex disease. For decades, Pavlovian fear conditioning has been a dominant paradigm for studying the effects of trauma through an associative learning framework. However, severe stress also causes long-lasting nonassociative fear sensitization, which is often overlooked in Pavlovian fear conditioning studies. This paper synthesizes recent research on the stress-enhanced fear learning (SEFL) paradigm, a valuable rodent model that can dissociate associative and nonassociative effects of stress. We discuss evidence that the SEFL paradigm produces nonassociative fear sensitization that is distinguishable from Pavlovian fear conditioning. We also discuss key biological variables, such as age and sex, neural circuit mechanisms, and crucial gaps in knowledge. We argue that nonassociative fear sensitization deserves more attention within current PTSD models and that SEFL provides a valuable complement to Pavlovian conditioning research on trauma-related pathology.
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Affiliation(s)
- Kenji J Nishimura
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, USA, 78712
| | - Andrew Poulos
- Department of Psychology and Center for Neuroscience Research, State University of New York at Albany, Albany, USA, 12222
| | - Michael R Drew
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, USA, 78712
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58
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Stimulation of the ventromedial prefrontal cortex blocks the return of subcortically mediated fear responses. Transl Psychiatry 2022; 12:394. [PMID: 36127327 PMCID: PMC9489865 DOI: 10.1038/s41398-022-02174-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 09/07/2022] [Accepted: 09/09/2022] [Indexed: 11/08/2022] Open
Abstract
The ventromedial prefrontal cortex (vmPFC) mediates the inhibition of defensive responses upon encounters of cues, that had lost their attribute as a threat signal via previous extinction learning. Here, we investigated whether such fear extinction recall can be facilitated by anodal transcranial direct current stimulation (tDCS). Extinction recall was tested twenty-four hours after previously acquired fear was extinguished. Either anodal tDCS or sham stimulation targeting the vmPFC was applied during this test. After stimulation ceased, we examined return of fear after subjects had been re-exposed to aversive events. Fear was assessed by reports of threat expectancy and modulations of autonomic (skin conductance, heart rate) and protective reflex (startle potentiation) measures, the latter of which are mediated by subcortical defense circuits. While tDCS did not affect initial extinction recall, it abolished the return of startle potentiation and autonomic components of the fear response. Results suggest hierarchical multi-level vmPFC functions in human fear inhibition and indicate, that its stimulation might immunize against relapses into pathological subcortically mediated defensive activation.
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59
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Neural activity in afferent projections to the infralimbic cortex is associated with individual differences in the recall of fear extinction. Sci Rep 2022; 12:13703. [PMID: 35953525 PMCID: PMC9372091 DOI: 10.1038/s41598-022-17895-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/02/2022] [Indexed: 11/08/2022] Open
Abstract
Post-traumatic stress disorder (PTSD) is characterized by an impaired ability to extinguish fear responses to trauma-associated cues. Studies in humans and non-human animals point to differences in the engagement of certain frontal cortical regions as key mediators determining whether or not fear extinction is successful, however the neural circuit interactions that dictate the differential involvement of these regions are not well understood. To better understand how individual differences in extinction recall are reflected in differences in neural circuit activity, we labeled projections to the infralimbic cortex (IL) in rats using a retrograde tracer and compared neural activity within, and outside, of IL-projecting neurons. We analyzed these data in groups separated on the basis of how well rats retained extinction memory. We found that within IL-projecting cells, neurons in the posterior paraventricular thalamus showed heightened activity in rats that showed good extinction recall. Outside of the IL-projecting cells, increased Fos activity was observed in good extinction rats in select regions of the claustrum and ventral hippocampus. Our results indicate that differences in extinction recall are associated with a specific pattern of neural activity both within and outside of projections to the IL.
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60
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Prefrontal cortical circuits in anxiety and fear: an overview. Front Med 2022; 16:518-539. [PMID: 35943704 DOI: 10.1007/s11684-022-0941-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 06/06/2022] [Indexed: 11/04/2022]
Abstract
Pathological anxiety is among the most difficult neuropsychiatric diseases to treat pharmacologically, and it represents a major societal problem. Studies have implicated structural changes within the prefrontal cortex (PFC) and functional changes in the communication of the PFC with distal brain structures in anxiety disorders. Treatments that affect the activity of the PFC, including cognitive therapies and transcranial magnetic stimulation, reverse anxiety- and fear-associated circuit abnormalities through mechanisms that remain largely unclear. While the subjective experience of a rodent cannot be precisely determined, rodent models hold great promise in dissecting well-conserved circuits. Newly developed genetic and viral tools and optogenetic and chemogenetic techniques have revealed the intricacies of neural circuits underlying anxiety and fear by allowing direct examination of hypotheses drawn from existing psychological concepts. This review focuses on studies that have used these circuit-based approaches to gain a more detailed, more comprehensive, and more integrated view on how the PFC governs anxiety and fear and orchestrates adaptive defensive behaviors to hopefully provide a roadmap for the future development of therapies for pathological anxiety.
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61
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Rosen JB, Schulkin J. Hyperexcitability: From Normal Fear to Pathological Anxiety and Trauma. Front Syst Neurosci 2022; 16:727054. [PMID: 35993088 PMCID: PMC9387392 DOI: 10.3389/fnsys.2022.727054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 06/20/2022] [Indexed: 11/16/2022] Open
Abstract
Hyperexcitability in fear circuits is suggested to be important for development of pathological anxiety and trauma from adaptive mechanisms of fear. Hyperexcitability is proposed to be due to acquired sensitization in fear circuits that progressively becomes more severe over time causing changing symptoms in early and late pathology. We use the metaphor and mechanisms of kindling to examine gains and losses in function of one excitatory and one inhibitory neuropeptide, corticotrophin releasing factor and somatostatin, respectively, to explore this sensitization hypothesis. We suggest amygdala kindling induced hyperexcitability, hyper-inhibition and loss of inhibition provide clues to mechanisms for hyperexcitability and progressive changes in function initiated by stress and trauma.
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Affiliation(s)
- Jeffrey B. Rosen
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
- *Correspondence: Jeffrey B. Rosen,
| | - Jay Schulkin
- School of Medicine, University of Washington, Seattle, WA, United States
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Vasudevan K, Ramanathan KR, Vierkant V, Maren S. Nucleus reuniens inactivation does not impair consolidation or reconsolidation of fear extinction. LEARNING & MEMORY (COLD SPRING HARBOR, N.Y.) 2022; 29:216-222. [PMID: 35902273 PMCID: PMC9374271 DOI: 10.1101/lm.053611.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/01/2022] [Indexed: 11/24/2022]
Abstract
Recent data reveal that the thalamic nucleus reuniens (RE) has a critical role in the extinction of conditioned fear. Muscimol (MUS) infusions into the RE impair within-session extinction of conditioned freezing and result in poor long-term extinction memories in rats. Although this suggests that RE inactivation impairs extinction learning, it is also possible that it is involved in the consolidation of extinction memories. To examine this possibility, we examined the effects of RE inactivation on the consolidation and reconsolidation of fear extinction in male and female rats. Twenty-four hours after auditory fear conditioning, rats underwent an extinction procedure (45 CS-alone trials) in a novel context and were infused with saline (SAL) or MUS within minutes of the final extinction trial. Twenty-four hours later, conditioned freezing to the extinguished CS was assessed in the extinction context. Postextinction inactivation of the RE did not affect extinction retrieval. In a second experiment, rats underwent extinction training and, 24 h later, were presented with a single CS to reactivate the extinction memory; rats were infused with SAL or MUS immediately after the reactivation session. Pharmacological inactivation of the RE did not affect conditioned freezing measured in a drug-free retrieval test the following day. Importantly, we found in a subsequent test that MUS infusions immediately before retrieval testing increased conditioned freezing and impaired extinction retrieval, as we have previously reported. These results indicate that although RE inactivation impairs the expression of extinction, it does not impair either the consolidation or reconsolidation of extinction memories. We conclude that the RE may have a critical role in suppressing context-inappropriate fear memories in the extinction context.
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Affiliation(s)
- Krithika Vasudevan
- Department of Psychological and Brain Sciences, Institute for Neuroscience, Texas A&M University, College Station, Texas 77843, USA
| | - Karthik R Ramanathan
- Department of Psychological and Brain Sciences, Institute for Neuroscience, Texas A&M University, College Station, Texas 77843, USA
| | - Valerie Vierkant
- Department of Psychological and Brain Sciences, Institute for Neuroscience, Texas A&M University, College Station, Texas 77843, USA
| | - Stephen Maren
- Department of Psychological and Brain Sciences, Institute for Neuroscience, Texas A&M University, College Station, Texas 77843, USA
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63
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Role of noradrenergic arousal for fear extinction processes in rodents and humans. Neurobiol Learn Mem 2022; 194:107660. [PMID: 35870717 DOI: 10.1016/j.nlm.2022.107660] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/29/2022] [Accepted: 07/17/2022] [Indexed: 01/22/2023]
Abstract
Fear extinction is a learning mechanism that is pivotal for the inhibition of fear responses towards cues or contexts that no longer predict the occurrence of a threat. Failure of fear extinction leads to fear expression under safe conditions and is regarded to be a cardinal characteristic of many anxiety-related disorders and posttraumatic stress disorder. Importantly, the neurotransmitter noradrenaline was shown to be a potent modulator of fear extinction. Rodent studies demonstrated that excessive noradrenaline transmission after acute stress opens a time window of vulnerability, in which fear extinction learning results in attenuated long-term extinction success. In contrast, when excessive noradrenergic transmission subsides, well-coordinated noradrenaline transmission is necessary for the formation of a long-lasting extinction memory. In addition, emerging evidence suggests that the neuropeptide corticotropin releasing hormone (CRF), which strongly regulates noradrenaline transmission under conditions of acute stress, also impedes long-term extinction success. Recent rodent work - using sophisticated methods - provides evidence for a hypothetical mechanistic framework of how noradrenaline and CRF dynamically orchestrate the neural fear and extinction circuitry to attenuate or to improve fear extinction and extinction recall. Accordingly, we review the evidence from rodent studies linking noradrenaline and CRF to fear extinction learning and recall and derive the hypothetical mechanistic framework of how different levels of noradrenaline and CRF may create a time window of vulnerability which impedes successful long-term fear extinction. We also address evidence from human studies linking noradrenaline and fear extinction success. Moreover, we accumulate emerging approaches to non-invasively measure and manipulate the noradrenergic system in healthy humans. Finally, we emphasize the importance of future studies to account for sex (hormone) differences when examining the interaction between fear extinction, noradrenaline, and CRF. To conclude, NA's effects on fear extinction recall strongly depend on the arousal levels at the onset of fear extinction learning. Our review aimed at compiling the available (mainly rodent) data in a neurobiological framework, suited to derive testable hypotheses for future work in humans.
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Mattera A, Cavallo A, Granato G, Baldassarre G, Pagani M. A Biologically Inspired Neural Network Model to Gain Insight Into the Mechanisms of Post-Traumatic Stress Disorder and Eye Movement Desensitization and Reprocessing Therapy. Front Psychol 2022; 13:944838. [PMID: 35911047 PMCID: PMC9326218 DOI: 10.3389/fpsyg.2022.944838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 06/06/2022] [Indexed: 01/09/2023] Open
Abstract
Eye movement desensitization and reprocessing (EMDR) therapy is a well-established therapeutic method to treat post-traumatic stress disorder (PTSD). However, how EMDR exerts its therapeutic action has been studied in many types of research but still needs to be completely understood. This is in part due to limited knowledge of the neurobiological mechanisms underlying EMDR, and in part to our incomplete understanding of PTSD. In order to model PTSD, we used a biologically inspired computational model based on firing rate units, encompassing the cortex, hippocampus, and amygdala. Through the modulation of its parameters, we fitted real data from patients treated with EMDR or classical exposure therapy. This allowed us to gain insights into PTSD mechanisms and to investigate how EMDR achieves trauma remission.
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65
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Totty MS, Maren S. Neural Oscillations in Aversively Motivated Behavior. Front Behav Neurosci 2022; 16:936036. [PMID: 35846784 PMCID: PMC9284508 DOI: 10.3389/fnbeh.2022.936036] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Fear and anxiety-based disorders are highly debilitating and among the most prevalent psychiatric disorders. These disorders are associated with abnormal network oscillations in the brain, yet a comprehensive understanding of the role of network oscillations in the regulation of aversively motivated behavior is lacking. In this review, we examine the oscillatory correlates of fear and anxiety with a particular focus on rhythms in the theta and gamma-range. First, we describe neural oscillations and their link to neural function by detailing the role of well-studied theta and gamma rhythms to spatial and memory functions of the hippocampus. We then describe how theta and gamma oscillations act to synchronize brain structures to guide adaptive fear and anxiety-like behavior. In short, that hippocampal network oscillations act to integrate spatial information with motivationally salient information from the amygdala during states of anxiety before routing this information via theta oscillations to appropriate target regions, such as the prefrontal cortex. Moreover, theta and gamma oscillations develop in the amygdala and neocortical areas during the encoding of fear memories, and interregional synchronization reflects the retrieval of both recent and remotely encoded fear memories. Finally, we argue that the thalamic nucleus reuniens represents a key node synchronizing prefrontal-hippocampal theta dynamics for the retrieval of episodic extinction memories in the hippocampus.
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Binette AN, Totty MS, Maren S. Sex differences in the immediate extinction deficit and renewal of extinguished fear in rats. PLoS One 2022; 17:e0264797. [PMID: 35687598 PMCID: PMC9187087 DOI: 10.1371/journal.pone.0264797] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/31/2022] [Indexed: 12/16/2022] Open
Abstract
Extinction learning is central to exposure-based behavioral therapies for reducing fear and anxiety in humans. However, patients with fear and anxiety disorders are often resistant to extinction. Moreover, trauma and stress-related disorders are highly prone to relapse and are twice as likely to occur in females compared to males, suggesting that females may be more susceptible to extinction deficits and fear relapse phenomena. In this report, we tested this hypothesis by examining sex differences in a stress-induced extinction learning impairment, the immediate extinction deficit (IED), and renewal, a common form of fear relapse. In contrast to our hypothesis, there were no sex differences in the magnitude of the immediate extinction deficit in two different rat strains (Long-Evans and Wistar). However, we did observe a sex difference in the renewal of fear when the extinguished conditioned stimulus was presented outside the extinction context. Male Wistar rats exhibited significantly greater renewal than female rats, a sex difference that has previously been reported after appetitive extinction. Collectively, these data reveal that stress-induced extinction impairments are similar in male and female rats, though the context-dependence of extinction is more pronounced in males.
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Affiliation(s)
- Annalise N. Binette
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, Texas, United States of America
| | - Michael S. Totty
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, Texas, United States of America
| | - Stephen Maren
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, Texas, United States of America
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Pathway-specific inhibition of critical projections from the mediodorsal thalamus to the frontal cortex controls kindled seizures. Prog Neurobiol 2022; 214:102286. [PMID: 35537572 DOI: 10.1016/j.pneurobio.2022.102286] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/22/2022] [Accepted: 05/04/2022] [Indexed: 02/07/2023]
Abstract
There is a large unmet need for improved treatment for temporal lobe epilepsy (TLE); circuit-specific manipulation that disrupts the initiation and propagation of seizures is promising in this regard. The midline thalamus, including the mediodorsal nucleus (MD) is a critical distributor of seizure activity, but its afferent and efferent pathways that mediate seizure activity are unknown. Here, we used chemogenetics to silence input and output projections of the MD to discrete regions of the frontal cortex in the kindling model of TLE in rats. Chemogenetic inhibition of the projection from the amygdala to the MD abolished seizures, an effect that was replicated using optogenetic inhibition. Chemogenetic inhibition of projections from the MD to the prelimbic cortex likewise abolished seizures. By contrast, inhibition of projections from the MD to other frontal regions produced partial (orbitofrontal cortex, infralimbic cortex) or no (cingulate, insular cortex) attenuation of behavioral or electrographic seizure activity. These results highlight the particular importance of projections from MD to prelimbic cortex in the propagation of amygdala-kindled seizures.
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68
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Han X, Song X, Song D, Xie G, Guo H, Wu N, Li J. Comparison between cannabidiol and sertraline for the modulation of post-traumatic stress disorder-like behaviors and fear memory in mice. Psychopharmacology (Berl) 2022; 239:1605-1620. [PMID: 35396940 DOI: 10.1007/s00213-022-06132-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 03/28/2022] [Indexed: 12/30/2022]
Abstract
RATIONALE AND OBJECTIVES Post-traumatic stress disorder (PTSD) is characterized by poor adaptation to a traumatic experience and disturbances in fear memory regulation, and currently lacks effective medication. Cannabidiol is a main constituent of Cannabis sativa; it has no psychotomimetic effects and has been implicated in modulating fear learning in mammals. Using a mouse PTSD model, we investigated the effects of CBD on PTSD-like behaviors and the modulation of trauma-related fear memory, a crucial process leading to core symptoms of PTSD. METHODS We applied the modified pre-shock model to evaluated PTSD-like behaviors from days 3 to 26. The measures included the freezing time to the conditioned context, open field test, elevated plus maze test, and social interaction test. CBD and sertraline were administered at different stages of fear memory. RESULTS CBD (10 mg/kg, i.p.) administration alleviated main PTSD-like symptoms in the mouse pre-shock model by attenuating trauma-related fear memory and anxiety-like behavior, and increasing social interaction behavior. The effects of CBD were apparent irrespective of whether it was administered before, during, or after re-exposure to the aversive context. However, sertraline (15 mg/kg, p.o.) was only effective when administered before the behavioral test. CBD also reduced the consolidation, retrieval, and reconsolidation of trauma-related fear memory, whereas sertraline only reduced fear-memory retrieval. CONCLUSION CBD produced anti-PTSD-like actions in mice and disrupted trauma-related fear memory by interfering with multiple aspects of fear memory processing. These findings indicate that CBD may be a promising candidate for treating PTSD.
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Affiliation(s)
- Xiao Han
- Beijing Key Laboratory of Neuropsychopharmacology, State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China.
| | - Xiankui Song
- Beijing Key Laboratory of Neuropsychopharmacology, State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Dake Song
- Beijing Key Laboratory of Neuropsychopharmacology, State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Guanbo Xie
- Beijing Key Laboratory of Neuropsychopharmacology, State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Hongyan Guo
- Shanxi Medical University School and Hospital of Stomatology, Taiyuan, 030001, China
| | - Ning Wu
- Beijing Key Laboratory of Neuropsychopharmacology, State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China.
| | - Jin Li
- Beijing Key Laboratory of Neuropsychopharmacology, State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
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69
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Narvaes RF, Nachtigall EG, Marcondes LA, Izquierdo I, Myskiw JDC, Furini CR. Involvement of medial prefrontal cortex canonical Wnt/β-catenin and non-canonical Wnt/Ca2+ signaling pathways in contextual fear memory in male rats. Behav Brain Res 2022; 430:113948. [DOI: 10.1016/j.bbr.2022.113948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 04/25/2022] [Accepted: 05/24/2022] [Indexed: 11/02/2022]
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70
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Raut SB, Marathe PA, van Eijk L, Eri R, Ravindran M, Benedek DM, Ursano RJ, Canales JJ, Johnson LR. Diverse therapeutic developments for post-traumatic stress disorder (PTSD) indicate common mechanisms of memory modulation. Pharmacol Ther 2022; 239:108195. [PMID: 35489438 DOI: 10.1016/j.pharmthera.2022.108195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 12/20/2022]
Abstract
Post-traumatic stress disorder (PTSD), characterized by abnormally persistent and distressing memories, is a chronic debilitating condition in need of new treatment options. Current treatment guidelines recommend psychotherapy as first line management with only two drugs, sertraline and paroxetine, approved by U.S. Food and Drug Administration (FDA) for treatment of PTSD. These drugs have limited efficacy as they only reduce symptoms related to depression and anxiety without producing permanent remission. PTSD remains a significant public health problem with high morbidity and mortality requiring major advances in therapeutics. Early evidence has emerged for the beneficial effects of psychedelics particularly in combination with psychotherapy for management of PTSD, including psilocybin, MDMA, LSD, cannabinoids, ayahuasca and ketamine. MDMA and psilocybin reduce barrier to therapy by increasing trust between therapist and patient, thus allowing for modification of trauma related memories. Furthermore, research into the memory reconsolidation mechanisms has allowed for identification of various pharmacological targets to disrupt abnormally persistent memories. A number of pre-clinical and clinical studies have investigated novel and re-purposed pharmacological agents to disrupt fear memory in PTSD. Novel therapeutic approaches like neuropeptide Y, oxytocin, cannabinoids and neuroactive steroids have also shown potential for PTSD treatment. Here, we focus on the role of fear memory in the pathophysiology of PTSD and propose that many of these new therapeutic strategies produce benefits through the effect on fear memory. Evaluation of recent research findings suggests that while a number of drugs have shown promising results in preclinical studies and pilot clinical trials, the evidence from large scale clinical trials would be needed for these drugs to be incorporated in clinical practice.
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Affiliation(s)
- Sanket B Raut
- Schools of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia
| | - Padmaja A Marathe
- Department of Pharmacology and Therapeutics, Seth GS Medical College & KEM Hospital, Parel, Mumbai 400 012, India
| | - Liza van Eijk
- Department of Psychology, College of Healthcare Sciences, James Cook University, QLD 4811, Australia
| | - Rajaraman Eri
- Health Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia
| | - Manoj Ravindran
- Medicine, College of Health and Medicine, University of Tasmania, TAS 7250, Australia; Department of Psychiatry, North-West Private Hospital, Burnie TAS 7320, Australia
| | - David M Benedek
- Centre for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD 20814, USA
| | - Robert J Ursano
- Centre for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD 20814, USA
| | - Juan J Canales
- Schools of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia
| | - Luke R Johnson
- Schools of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia; Centre for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD 20814, USA.
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Maren S. Unrelenting Fear Under Stress: Neural Circuits and Mechanisms for the Immediate Extinction Deficit. Front Syst Neurosci 2022; 16:888461. [PMID: 35520882 PMCID: PMC9062589 DOI: 10.3389/fnsys.2022.888461] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
Therapeutic interventions for disorders of fear and anxiety rely on behavioral approaches that reduce pathological fear memories. For example, learning that threat-predictive stimuli are no longer associated with aversive outcomes is central to the extinction of conditioned fear responses. Unfortunately, fear memories are durable, long-lasting, and resistant to extinction, particularly under high levels of stress. This is illustrated by the "immediate extinction deficit," which is characterized by a poor long-term reduction of conditioned fear when extinction procedures are attempted within hours of fear conditioning. Here, I will review recent work that has provided new insight into the neural mechanisms underlying resistance to fear extinction. Emerging studies reveal that locus coeruleus norepinephrine modulates amygdala-prefrontal cortical circuits that are critical for extinction learning. These data suggest that stress-induced activation of brain neuromodulatory systems biases fear memory at the expense of extinction learning. Behavioral and pharmacological strategies to reduce stress in patients undergoing exposure therapy might improve therapeutic outcomes.
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Affiliation(s)
- Stephen Maren
- Department of Psychological and Brain Sciences, Institute for Neuroscience, Texas A&M University, College Station, TX, United States
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72
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Howland JG, Ito R, Lapish CC, Villaruel FR. The rodent medial prefrontal cortex and associated circuits in orchestrating adaptive behavior under variable demands. Neurosci Biobehav Rev 2022; 135:104569. [PMID: 35131398 PMCID: PMC9248379 DOI: 10.1016/j.neubiorev.2022.104569] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 12/17/2021] [Accepted: 02/01/2022] [Indexed: 11/28/2022]
Abstract
Emerging evidence implicates rodent medial prefrontal cortex (mPFC) in tasks requiring adaptation of behavior to changing information from external and internal sources. However, the computations within mPFC and subsequent outputs that determine behavior are incompletely understood. We review the involvement of mPFC subregions, and their projections to the striatum and amygdala in two broad types of tasks in rodents: 1) appetitive and aversive Pavlovian and operant conditioning tasks that engage mPFC-striatum and mPFC-amygdala circuits, and 2) foraging-based tasks that require decision making to optimize reward. We find support for region-specific function of the mPFC, with dorsal mPFC and its projections to the dorsomedial striatum supporting action control with higher cognitive demands, and ventral mPFC engagement in translating affective signals into behavior via discrete projections to the ventral striatum and amygdala. However, we also propose that defined mPFC subdivisions operate as a functional continuum rather than segregated functional units, with crosstalk that allows distinct subregion-specific inputs (e.g., internal, affective) to influence adaptive behavior supported by other subregions.
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Affiliation(s)
- John G Howland
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada.
| | - Rutsuko Ito
- Department of Psychology, University of Toronto-Scarborough, Toronto, ON, Canada.
| | - Christopher C Lapish
- Department of Psychology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA.
| | - Franz R Villaruel
- Department of Psychology, Concordia University, Montreal, QC, Canada.
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73
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Namkung H, Thomas KL, Hall J, Sawa A. Parsing neural circuits of fear learning and extinction across basic and clinical neuroscience: Towards better translation. Neurosci Biobehav Rev 2022; 134:104502. [PMID: 34921863 DOI: 10.1016/j.neubiorev.2021.12.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/22/2022]
Abstract
Over the past decades, studies of fear learning and extinction have advanced our understanding of the neurobiology of threat and safety learning. Animal studies can provide mechanistic/causal insights into human brain regions and their functional connectivity involved in fear learning and extinction. Findings in humans, conversely, may further enrich our understanding of neural circuits in animals by providing macroscopic insights at the level of brain-wide networks. Nevertheless, there is still much room for improvement in translation between basic and clinical research on fear learning and extinction. Through the lens of neural circuits, in this article, we aim to review the current knowledge of fear learning and extinction in both animals and humans, and to propose strategies to fill in the current knowledge gap for the purpose of enhancing clinical benefits.
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Affiliation(s)
- Ho Namkung
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Kerrie L Thomas
- Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK; School of Biosciences, Cardiff University, Cardiff, UK
| | - Jeremy Hall
- Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK; School of Medicine, Cardiff University, Cardiff, UK
| | - Akira Sawa
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Mental Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, 21287, USA.
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74
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Subfornical organ interleukin 1 receptor: A novel regulator of spontaneous and conditioned fear associated behaviors in mice. Brain Behav Immun 2022; 101:304-317. [PMID: 35032573 PMCID: PMC9836229 DOI: 10.1016/j.bbi.2022.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 12/25/2021] [Accepted: 01/07/2022] [Indexed: 01/14/2023] Open
Abstract
Impaired threat responding and fear regulation is a hallmark of psychiatric conditions such as post-traumatic stress disorder (PTSD) and Panic Disorder (PD). Most studies have focused on external psychogenic threats to study fear, however, accumulating evidence suggests a primary role of homeostatic perturbations and interoception in regulating emotional behaviors. Heightened reactivity to interoceptive threat carbon dioxide (CO2) inhalation associates with increased risk for developing PD and PTSD, however, contributory mechanisms and molecular targets are not well understood. Previous studies from our group suggested a potential role of interleukin 1 receptor (IL-1R1) signaling within BBB-devoid sensory circumventricular organ, the subfornical organ (SFO) in CO2-evoked fear. However, the necessity of SFO-IL-1R1 in regulating CO2-associated spontaneous fear as well as, long-term fear potentiation relevant to PD/PTSD has not been investigated. The current study tested male mice with SFO-targeted microinfusion of the IL-1R1 antagonist (IL-1RA) or vehicle in a recently developed CO2-startle-fear conditioning-extinction paradigm. Consistent with our hypothesis, SFO IL-1RA treatment elicited significant attenuation of freezing and increased rearing during CO2 inhalation suggesting SFO-IL1R1 regulation of spontaneous fear to CO2. Intriguingly, SFO IL-1RA treatment normalized CO2-associated potentiation of conditioned fear and impaired extinction a week later suggesting modulation of long-term fear by SFO-IL-1R1 signaling. Post behavior FosB mapping revealed recruitment of prefrontal cortex-amygdala-periaqueductal gray (PAG) areas in SFO-IL-1RA mediated effects. Additionally, we localized cellular IL-1R1 expression within the SFO to blood vessel endothelial cells and observed CO2-induced alterations in IL-1β/IL-1R1 expression in peripheral mononuclear cells and SFO. Lastly, CO2-evoked microglial activation was attenuated in SFO-IL-1RA treated mice. These observations suggest a peripheral monocyte-endothelial-microglia interplay in SFO-IL-1R1 modulation of CO2-associated spontaneous fear and delayed fear memory. Collectively, our data highlight a novel, "bottom-up" neuroimmune mechanism that integrates interoceptive and exteroceptive threat processing of relevance to fear-related pathologies.
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75
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Pessoa L, Medina L, Desfilis E. Refocusing neuroscience: moving away from mental categories and towards complex behaviours. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200534. [PMID: 34957851 PMCID: PMC8710886 DOI: 10.1098/rstb.2020.0534] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 10/01/2021] [Indexed: 11/12/2022] Open
Abstract
Mental terms-such as perception, cognition, action, emotion, as well as attention, memory, decision-making-are epistemically sterile. We support our thesis based on extensive comparative neuroanatomy knowledge of the organization of the vertebrate brain. Evolutionary pressures have moulded the central nervous system to promote survival. Careful characterization of the vertebrate brain shows that its architecture supports an enormous amount of communication and integration of signals, especially in birds and mammals. The general architecture supports a degree of 'computational flexibility' that enables animals to cope successfully with complex and ever-changing environments. Here, we suggest that the vertebrate neuroarchitecture does not respect the boundaries of standard mental terms, and propose that neuroscience should aim to unravel the dynamic coupling between large-scale brain circuits and complex, naturalistic behaviours. This article is part of the theme issue 'Systems neuroscience through the lens of evolutionary theory'.
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Affiliation(s)
- Luiz Pessoa
- Department of Psychology, University of Maryland, College Park, MD 20742, USA
| | - Loreta Medina
- Department of Experimental Medicine, Institut de Recerca Biomèdica de Lleida Fundació Dr. Pifarré (IRBLleida), University of Lleida, 25198 Lleida, Spain
| | - Ester Desfilis
- Department of Experimental Medicine, Institut de Recerca Biomèdica de Lleida Fundació Dr. Pifarré (IRBLleida), University of Lleida, 25198 Lleida, Spain
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76
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Villaruel FR, Martins M, Chaudhri N. Corticostriatal Suppression of Appetitive Pavlovian Conditioned Responding. J Neurosci 2022; 42:834-849. [PMID: 34880119 PMCID: PMC8808725 DOI: 10.1523/jneurosci.1664-21.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/29/2021] [Accepted: 10/09/2021] [Indexed: 11/21/2022] Open
Abstract
The capacity to suppress learned responses is essential for animals to adapt in dynamic environments. Extinction is a process by which animals learn to suppress conditioned responding when an expected outcome is omitted. The infralimbic (IL) cortex to nucleus accumbens shell (NAcS) neural circuit is implicated in suppressing conditioned responding after extinction, especially in the context of operant cocaine-seeking behavior. However, the role of the IL-to-NAcS neural circuit in the extinction of responding to appetitive Pavlovian cues is unknown, and the psychological mechanisms involved in response suppression following extinction are unclear. We trained male Long Evans rats to associate a 10 s auditory conditioned stimulus (CS; 14 trials per session) with a sucrose unconditioned stimulus (US; 0.2 ml per CS) in a specific context, and then following extinction in a different context, precipitated a renewal of CS responding by presenting the CS alone in the original Pavlovian conditioning context. Unilateral, optogenetic stimulation of the IL-to-NAcS circuit selectively during CS trials suppressed renewal. In a separate experiment, IL-to-NAcS stimulation suppressed CS responding regardless of prior extinction and impaired extinction retrieval. Finally, IL-to-NAcS stimulation during the CS did not suppress the acquisition of Pavlovian conditioning but was required for the subsequent expression of CS responding. These results are consistent with multiple studies showing that the IL-to-NAcS neural circuit is involved in the suppression of operant cocaine-seeking, extending these findings to appetitive Pavlovian cues. The suppression of appetitive Pavlovian responding following IL-to-NAcS circuit stimulation, however, does not appear to be an extinction-dependent process.SIGNIFICANCE STATEMENT Extinction is a form of inhibitory learning through which animals learn to suppress conditioned responding in the face of nonreinforcement. We investigated the role of the IL cortex inputs to the NAcS in the extinction of responding to appetitive Pavlovian cues and the psychological mechanisms involved in response suppression following extinction. Using in vivo optogenetics, we found that stimulating the IL-to-NAcS neural circuit suppressed context-induced renewal of conditioned responding after extinction. In a separate experiment, stimulating the IL-to-NAcS circuit suppressed conditioned responding in an extinction-independent manner. These findings can be used by future research aimed at understanding how corticostriatal circuits contribute to behavioral flexibility and mental disorders that involve the suppression of learned behaviors.
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Affiliation(s)
- Franz R Villaruel
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Melissa Martins
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Nadia Chaudhri
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, Quebec H4B 1R6, Canada
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77
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PV network plasticity mediated by neuregulin1-ErbB4 signalling controls fear extinction. Mol Psychiatry 2022; 27:896-906. [PMID: 34697452 DOI: 10.1038/s41380-021-01355-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 10/02/2021] [Accepted: 10/06/2021] [Indexed: 11/09/2022]
Abstract
Neuroplasticity in the medial prefrontal cortex (mPFC) is essential for fear extinction, the process of which forms the basis of the general therapeutic process used to treat human fear disorders. However, the underlying molecules and local circuit elements controlling neuronal activity and concomitant induction of plasticity remain unclear. Here we show that sustained plasticity of the parvalbumin (PV) neuronal network in the infralimbic (IL) mPFC is required for fear extinction in adult male mice and identify the involvement of neuregulin 1-ErbB4 signalling in PV network plasticity-mediated fear extinction. Moreover, regulation of fear extinction by basal medial amygdala (BMA)-projecting IL neurons is dependent on PV network configuration. Together, these results uncover the local molecular circuit mechanisms underlying mPFC-mediated top-down control of fear extinction, suggesting alterative therapeutic approaches to treat fear disorders.
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78
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Hennings AC, McClay M, Drew MR, Lewis-Peacock JA, Dunsmoor JE. Neural reinstatement reveals divided organization of fear and extinction memories in the human brain. Curr Biol 2022; 32:304-314.e5. [PMID: 34813732 PMCID: PMC8792329 DOI: 10.1016/j.cub.2021.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/28/2021] [Accepted: 11/02/2021] [Indexed: 01/26/2023]
Abstract
Neurobiological research in rodents has revealed that competing experiences of fear and extinction are stored as distinct memory traces in the brain. This divided organization is adaptive for mitigating overgeneralization of fear to related stimuli that are learned to be safe while also maintaining threat associations for unsafe stimuli. The mechanisms involved in organizing these competing memories in the human brain remain unclear. Here, we used a hybrid form of Pavlovian conditioning with an episodic memory component to identify overlapping multivariate patterns of fMRI activity associated with the formation and retrieval of fear versus extinction. In healthy adults, distinct regions of the medial prefrontal cortex (PFC) and hippocampus showed selective reactivation of fear versus extinction memories based on the temporal context in which these memories were encoded. This dissociation was absent in participants with posttraumatic stress disorder (PTSD) symptoms. The divided neural organization of fear and extinction may support flexible retrieval of context-appropriate emotional memories, while their disorganization may promote overgeneralization and increased fear relapse in affective disorders.
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Affiliation(s)
- Augustin C Hennings
- Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA; Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
| | - Mason McClay
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Michael R Drew
- Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA; Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
| | - Jarrod A Lewis-Peacock
- Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA; Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, TX, USA; Department of Psychology, University of Texas at Austin, Austin, TX, USA; Department of Psychiatry, Dell Medical School, University of Texas at Austin, Austin, TX, USA
| | - Joseph E Dunsmoor
- Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA; Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, TX, USA; Department of Psychiatry, Dell Medical School, University of Texas at Austin, Austin, TX, USA.
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79
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Canto-de-Souza L, Demetrovich PG, Plas S, Souza RR, Epperson J, Wahlstrom KL, Nunes-de-Souza RL, LaLumiere RT, Planeta CS, McIntyre CK. Daily Optogenetic Stimulation of the Left Infralimbic Cortex Reverses Extinction Impairments in Male Rats Exposed to Single Prolonged Stress. Front Behav Neurosci 2022; 15:780326. [PMID: 34987362 PMCID: PMC8721142 DOI: 10.3389/fnbeh.2021.780326] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/02/2021] [Indexed: 11/13/2022] Open
Abstract
Post-traumatic stress disorder (PTSD) is associated with decreased activity in the prefrontal cortex. PTSD-like pathophysiology and behaviors have been observed in rodents exposed to a single prolonged stress (SPS) procedure. When animals are left alone for 7 days after SPS treatment, they show increased anxiety-like behavior and impaired extinction of conditioned fear, and reduced activity in the prefrontal cortex. Here, we tested the hypothesis that daily optogenetic stimulation of the infralimbic region (IL) of the medial prefrontal cortex (mPFC) during the 7 days after SPS would reverse SPS effects on anxiety and fear extinction. Male Sprague-Dawley rats underwent SPS and then received daily optogenetic stimulation (20 Hz, 2 s trains, every 10 s for 15 min/day) of glutamatergic neurons of the left or right IL for seven days. After this incubation period, rats were tested in the elevated plus-maze (EPM). Twenty-four hours after the EPM test, rats underwent auditory fear conditioning (AFC), extinction training and a retention test. SPS increased anxiety-like behavior in the EPM task and produced a profound impairment in extinction of AFC. Optogenetic stimulation of the left IL, but not right, during the 7-day incubation period reversed the extinction impairment. Optogenetic stimulation did not reverse the increased anxiety-like behavior, suggesting that the extinction effects are not due to a treatment-induced reduction in anxiety. Results indicate that increased activity of the left IL after traumatic experiences can prevent development of extinction impairments. These findings suggest that non-invasive brain stimulation may be a useful tool for preventing maladaptive responses to trauma.
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Affiliation(s)
- Lucas Canto-de-Souza
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, Brazil.,Institute of Neuroscience and Behavior, Ribeirão Preto, Brazil.,School of Behavior and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
| | - Peyton G Demetrovich
- School of Behavior and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
| | - Samantha Plas
- School of Behavior and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
| | - Rimenez R Souza
- School of Behavior and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States.,Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Joseph Epperson
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Krista L Wahlstrom
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, United States
| | - Ricardo Luiz Nunes-de-Souza
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, Brazil.,Institute of Neuroscience and Behavior, Ribeirão Preto, Brazil.,Joint Graduate Program in Physiological Sciences, Universidade Federal de São Carlos - UFSCar/UNESP, São Carlos, Brazil
| | - Ryan T LaLumiere
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, United States.,Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, United States
| | - Cleopatra Silva Planeta
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, Brazil.,Joint Graduate Program in Physiological Sciences, Universidade Federal de São Carlos - UFSCar/UNESP, São Carlos, Brazil
| | - Christa K McIntyre
- School of Behavior and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States.,Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
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80
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Anderson MC, Floresco SB. Prefrontal-hippocampal interactions supporting the extinction of emotional memories: the retrieval stopping model. Neuropsychopharmacology 2022; 47:180-195. [PMID: 34446831 PMCID: PMC8616908 DOI: 10.1038/s41386-021-01131-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023]
Abstract
Neuroimaging has revealed robust interactions between the prefrontal cortex and the hippocampus when people stop memory retrieval. Efforts to stop retrieval can arise when people encounter reminders to unpleasant thoughts they prefer not to think about. Retrieval stopping suppresses hippocampal and amygdala activity, especially when cues elicit aversive memory intrusions, via a broad inhibitory control capacity enabling prepotent response suppression. Repeated retrieval stopping reduces intrusions of unpleasant memories and diminishes their affective tone, outcomes resembling those achieved by the extinction of conditioned emotional responses. Despite this resemblance, the role of inhibitory fronto-hippocampal interactions and retrieval stopping broadly in extinction has received little attention. Here we integrate human and animal research on extinction and retrieval stopping. We argue that reconceptualising extinction to integrate mnemonic inhibitory control with learning would yield a greater understanding of extinction's relevance to mental health. We hypothesize that fear extinction spontaneously engages retrieval stopping across species, and that controlled suppression of hippocampal and amygdala activity by the prefrontal cortex reduces fearful thoughts. Moreover, we argue that retrieval stopping recruits extinction circuitry to achieve affect regulation, linking extinction to how humans cope with intrusive thoughts. We discuss novel hypotheses derived from this theoretical synthesis.
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Affiliation(s)
- Michael C Anderson
- MRC Cognition & Brain Sciences Unit, University of Cambridge, Cambridge, UK.
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
| | - Stan B Floresco
- Department of Psychology, and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
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81
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Alexandra Kredlow M, Fenster RJ, Laurent ES, Ressler KJ, Phelps EA. Prefrontal cortex, amygdala, and threat processing: implications for PTSD. Neuropsychopharmacology 2022; 47:247-259. [PMID: 34545196 PMCID: PMC8617299 DOI: 10.1038/s41386-021-01155-7] [Citation(s) in RCA: 89] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 08/03/2021] [Accepted: 08/06/2021] [Indexed: 02/08/2023]
Abstract
Posttraumatic stress disorder can be viewed as a disorder of fear dysregulation. An abundance of research suggests that the prefrontal cortex is central to fear processing-that is, how fears are acquired and strategies to regulate or diminish fear responses. The current review covers foundational research on threat or fear acquisition and extinction in nonhuman animals, healthy humans, and patients with posttraumatic stress disorder, through the lens of the involvement of the prefrontal cortex in these processes. Research harnessing advances in technology to further probe the role of the prefrontal cortex in these processes, such as the use of optogenetics in rodents and brain stimulation in humans, will be highlighted, as well other fear regulation approaches that are relevant to the treatment of posttraumatic stress disorder and involve the prefrontal cortex, namely cognitive regulation and avoidance/active coping. Despite the large body of translational research, many questions remain unanswered and posttraumatic stress disorder remains difficult to treat. We conclude by outlining future research directions related to the role of the prefrontal cortex in fear processing and implications for the treatment of posttraumatic stress disorder.
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Affiliation(s)
- M. Alexandra Kredlow
- grid.38142.3c000000041936754XDepartment of Psychology, Harvard University, Cambridge, MA USA
| | - Robert J. Fenster
- grid.38142.3c000000041936754XDivision of Depression and Anxiety, McLean Hospital; Department of Psychiatry, Harvard Medical School, Cambridge, MA USA
| | - Emma S. Laurent
- grid.38142.3c000000041936754XDepartment of Psychology, Harvard University, Cambridge, MA USA
| | - Kerry J. Ressler
- grid.38142.3c000000041936754XDivision of Depression and Anxiety, McLean Hospital; Department of Psychiatry, Harvard Medical School, Cambridge, MA USA
| | - Elizabeth A. Phelps
- grid.38142.3c000000041936754XDepartment of Psychology, Harvard University, Cambridge, MA USA
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82
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Sottile RJ, Vida T. A proposed mechanism for the MDMA-mediated extinction of traumatic memories in PTSD patients treated with MDMA-assisted therapy. Front Psychiatry 2022; 13:991753. [PMID: 36311515 PMCID: PMC9596814 DOI: 10.3389/fpsyt.2022.991753] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/29/2022] [Indexed: 11/29/2022] Open
Abstract
Post-traumatic stress disorder (PTSD) is a devastating psychiatric disorder afflicting millions of people around the world. Characterized by severe anxiety, intrusive thoughts, pervasive nightmares, an assortment of somatic symptoms, associations with severe long-term health problems, and an elevated risk of suicide, as much as 40-70% of patients suffer from refractory disease. 3,4-Methylenedioxy-methamphetamine (MDMA), like classic psychedelics such as psilocybin, have been used to enhance the efficacy of psychotherapy almost since their discovery, but due to their perceived potential for abuse and inclusion on USFDA (United States Food and Drug Administration) schedule 1, research into the mechanism by which they produce improvements in PTSD symptomology has been limited. Nevertheless, several compelling rationales have been explored, with the pro-social effects of MDMA thought to enhance therapeutic alliance and thus facilitate therapist-assisted trauma processing. This may be insufficient to fully explain the efficacy of MDMA in the treatment of psychiatric illness. Molecular mechanisms such as the MDMA mediated increase of brain-derived neurotrophic factor (BDNF) availability in the fear memory learning pathways combined with MDMA's pro-social effects may provide a more nuanced explanation for the therapeutic actions of MDMA.
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Affiliation(s)
- Robert J Sottile
- Department of Medical Education, Kirk Kerkorian School of Medicine at UNLV, University of Nevada Las Vegas, Las Vegas, NV, United States
| | - Thomas Vida
- Department of Medical Education, Kirk Kerkorian School of Medicine at UNLV, University of Nevada Las Vegas, Las Vegas, NV, United States
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83
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Watanabe M, Uematsu A, Johansen JP. Enhanced synchronization between prelimbic and infralimbic cortices during fear extinction learning. Mol Brain 2021; 14:175. [PMID: 34895283 PMCID: PMC8666018 DOI: 10.1186/s13041-021-00884-6] [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] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/24/2021] [Indexed: 01/05/2023] Open
Abstract
The ability to extinguish aversive memories when they are no longer associated with danger is critical for balancing survival with competing adaptive demands. Previous studies demonstrated that the infralimbic cortex (IL) is essential for extinction of learned fear, while neural activity in the prelimbic cortex (PL) facilitates fear responding and is negatively correlated with the strength of extinction memories. Though these adjacent regions in the prefrontal cortex maintain mutual synaptic connectivity, it has been unclear whether PL and IL interact functionally with each other during fear extinction learning. Here we addressed this question by recording local field potentials (LFPs) simultaneously from PL and IL of awake behaving rats during extinction of auditory fear memories. We found that LFP power in the fast gamma frequency (100-200 Hz) in both PL and IL regions increased during extinction learning. In addition, coherency analysis showed that synchronization between PL and IL in the fast gamma frequency was enhanced over the course of extinction. These findings support the hypothesis that interregional interactions between PL and IL increase as animals extinguish aversive memories.
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Affiliation(s)
- Mayumi Watanabe
- RIKEN Center for Brain Science, Wako-shi, Saitama, Japan.,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Akira Uematsu
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,International Research Center for Neurointelligence, The University of Tokyo, Tokyo, Japan
| | - Joshua P Johansen
- RIKEN Center for Brain Science, Wako-shi, Saitama, Japan. .,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan. .,RIKEN Center for Brain Science, Laboratory for Neural Circuitry of Learning and Memory, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
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84
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Meyer HC, Sangha S, Radley JJ, LaLumiere RT, Baratta MV. Environmental certainty influences the neural systems regulating responses to threat and stress. Neurosci Biobehav Rev 2021; 131:1037-1055. [PMID: 34673111 PMCID: PMC8642312 DOI: 10.1016/j.neubiorev.2021.10.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 10/20/2022]
Abstract
Flexible calibration of threat responding in accordance with the environment is an adaptive process that allows an animal to avoid harm while also maintaining engagement of other goal-directed actions. This calibration process, referred to as threat response regulation, requires an animal to calculate the probability that a given encounter will result in a threat so they can respond accordingly. Here we review the neural correlates of two highly studied forms of threat response suppression: extinction and safety conditioning. We focus on how relative levels of certainty or uncertainty in the surrounding environment alter the acquisition and application of these processes. We also discuss evidence indicating altered threat response regulation following stress exposure, including enhanced fear conditioning, and disrupted extinction and safety conditioning. To conclude, we discuss research using an animal model of coping that examines the impact of stressor controllability on threat responding, highlighting the potential for previous experiences with control, or other forms of coping, to protect against the effects of future adversity.
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Affiliation(s)
- Heidi C Meyer
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA.
| | - Susan Sangha
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA.
| | - Jason J Radley
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, 52242, USA.
| | - Ryan T LaLumiere
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, 52242, USA.
| | - Michael V Baratta
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO, 80301, USA.
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85
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Nett KE, LaLumiere RT. Infralimbic cortex functioning across motivated behaviors: Can the differences be reconciled? Neurosci Biobehav Rev 2021; 131:704-721. [PMID: 34624366 PMCID: PMC8642304 DOI: 10.1016/j.neubiorev.2021.10.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 09/10/2021] [Accepted: 10/02/2021] [Indexed: 10/20/2022]
Abstract
The rodent infralimbic cortex (IL) is implicated in higher order executive functions such as reward seeking and flexible decision making. However, the precise nature of its role in these processes is unclear. Early evidence indicated that the IL promotes the extinction and ongoing inhibition of fear conditioning and cocaine seeking. However, evidence spanning other behavioral domains, such as natural reward seeking and habit-based learning, suggests a more nuanced understanding of IL function. As techniques have advanced and more studies have examined IL function, identifying a unifying explanation for its behavioral function has become increasingly difficult. Here, we discuss evidence of IL function across motivated behaviors, including associative learning, drug seeking, natural reward seeking, and goal-directed versus habit-based behaviors, and emphasize how context-specific encoding and heterogeneous IL neuronal populations may underlie seemingly conflicting findings in the literature. Together, the evidence suggests that a major IL function is to facilitate the encoding and updating of contingencies between cues and behaviors to guide subsequent behaviors.
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Affiliation(s)
- Kelle E Nett
- Interdisciplinary Neuroscience Program, University of Iowa, Iowa City, IA 52242, United States.
| | - Ryan T LaLumiere
- Interdisciplinary Neuroscience Program, University of Iowa, Iowa City, IA 52242, United States; Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, United States
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86
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Wen Z, Hammoud MZ, Scott JC, Jimmy J, Brown L, Marin MF, Asnaani A, Gur RC, Foa EB, Milad MR. Impact of exogenous estradiol on task-based and resting-state neural signature during and after fear extinction in healthy women. Neuropsychopharmacology 2021; 46:2278-2287. [PMID: 34493827 PMCID: PMC8581031 DOI: 10.1038/s41386-021-01158-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 02/06/2023]
Abstract
Fluctuations of endogenous estrogen modulates fear extinction, but the influence of exogenous estradiol is less studied. Moreover, little focus has been placed on the impact of estradiol on broad network connectivity beyond the fear extinction circuit. Here, we examined the effect of acute exogenous estradiol administration on fear extinction-induced brain activation, whole-brain functional connectivity (FC) during the fear extinction task and post-extinction resting-state. Ninety healthy women (57 using oral contraceptives [OC], 33 naturally cycling [NC]) were fear conditioned on day 1. They ingested an estradiol or placebo pill prior to extinction learning on day 2 (double-blind design). Extinction memory was assessed on day 3. Task-based functional MRI data were ascertained on days 2 and 3 and resting-state data were collected post-extinction on day 2 and pre-recall on day 3. Estradiol administration significantly modulated the neural signature associated with fear extinction learning and memory, consistent with prior studies. Importantly, estradiol administration induced significant changes in FC within multiple networks, including the default mode and somatomotor networks during extinction learning, post-extinction, and during extinction memory recall. Exploratory analyses revealed that estradiol impacted ventromedial prefrontal cortex (vmPFC) activation and FC differently in the NC and OC women. The data implicate a more diffused and significant effect of acute estradiol administration on multiple networks. Such an effect might be beneficial to modulating attention and conscious processes in addition to engaging neural processes associated with emotional learning and memory consolidation.
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Affiliation(s)
- Zhenfu Wen
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA
| | - Mira Z Hammoud
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA
| | - J Cobb Scott
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- VISN4 Mental Illness Research, Education, and Clinical Center at the Philadelphia VA Medical Center, Philadelphia, PA, USA
| | - Jagan Jimmy
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA
| | - Lily Brown
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Marie-France Marin
- Departement of Psychology, Université du Québec à Montréal, Montreal, QC, Canada
- Research Center of the Institut universitaire en santé mentale de Montréal, Montreal, QC, Canada
| | - Anu Asnaani
- Department of Psychology, University of Utah, Salt Lake City, UT, USA
| | - Ruben C Gur
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Edna B Foa
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mohammed R Milad
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA.
- The Neuroscience Institute, New York University School of Medicine, New York, NY, USA.
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA.
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87
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The Medial Prefrontal Cortex and Fear Memory: Dynamics, Connectivity, and Engrams. Int J Mol Sci 2021; 22:ijms222212113. [PMID: 34830009 PMCID: PMC8619965 DOI: 10.3390/ijms222212113] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 01/08/2023] Open
Abstract
It is becoming increasingly apparent that long-term memory formation relies on a distributed network of brain areas. While the hippocampus has been at the center of attention for decades, it is now clear that other regions, in particular the medial prefrontal cortex (mPFC), are taking an active part as well. Recent evidence suggests that the mPFC-traditionally implicated in the long-term storage of memories-is already critical for the early phases of memory formation such as encoding. In this review, we summarize these findings, relate them to the functional importance of the mPFC connectivity, and discuss the role of the mPFC during memory consolidation with respect to the different theories of memory storage. Owing to its high functional connectivity to other brain areas subserving memory formation and storage, the mPFC emerges as a central hub across the lifetime of a memory, although much still remains to be discovered.
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88
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Bisby MA, Stylianakis AA, Baker KD, Richardson R. Fear extinction learning and retention during adolescence in rats and mice: A systematic review. Neurosci Biobehav Rev 2021; 131:1264-1274. [PMID: 34740753 DOI: 10.1016/j.neubiorev.2021.10.044] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 10/20/2021] [Accepted: 10/29/2021] [Indexed: 10/19/2022]
Abstract
Despite exposure-based treatments being recommended for anxiety disorders, these treatments are ineffective for over half of all adolescents who receive them. The limited efficacy of exposure during adolescence may be driven by a deficit in extinction. Although indications of diminished extinction learning during adolescence were first reported over 10 years ago, these findings have yet to be reviewed and compared. This review (k = 34) found a stark inter-species difference in extinction performance: studies of adolescent mice reported deficits in extinction learning and retention of both cued and context fear. In contrast, studies of adolescent rats only reported poor extinction retention specific to cued fear. Adolescent mice and rats appeared to have only one behavioral outcome in common, being poor extinction retention of cued fear. These findings suggest that different behavioral phenotypes are present across rodent species in adolescence and highlight that preclinical work in rats and mice is not interchangeable. Further investigation of these differences offers the opportunity to better understand the etiology, maintenance, and treatment of fear-based disorders.
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Affiliation(s)
- Madelyne A Bisby
- School of Psychology, UNSW Sydney, Sydney, 2052, NSW, Australia; eCentreClinic, School of Psychological Sciences, Faculty of Medicine and Health, Macquarie University, Sydney, 2109, NSW, Australia.
| | | | - Kathryn D Baker
- School of Psychology, UNSW Sydney, Sydney, 2052, NSW, Australia
| | - Rick Richardson
- School of Psychology, UNSW Sydney, Sydney, 2052, NSW, Australia
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89
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Mouly AM, Bouillot C, Costes N, Zimmer L, Ravel N, Litaudon P. PET Metabolic Imaging of Time-Dependent Reorganization of Olfactory Cued Fear Memory Networks in Rats. Cereb Cortex 2021; 32:2717-2728. [PMID: 34668524 DOI: 10.1093/cercor/bhab376] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 12/24/2022] Open
Abstract
Memory consolidation involves reorganization at both the synaptic and system levels. The latter involves gradual reorganization of the brain regions that support memory and has been mostly highlighted using hippocampal-dependent tasks. The standard memory consolidation model posits that the hippocampus becomes gradually less important over time in favor of neocortical regions. In contrast, this reorganization of circuits in amygdala-dependent tasks has been less investigated. Moreover, this question has been addressed using primarily lesion or cellular imaging approaches thus precluding the comparison of recent and remote memory networks in the same animals. To overcome this limitation, we used microPET imaging to characterize, in the same animals, the networks activated during the recall of a recent versus remote memory in an olfactory cued fear conditioning paradigm. The data highlighted the drastic difference between the extents of the two networks. Indeed, although the recall of a recent odor fear memory activates a large network of structures spanning from the prefrontal cortex to the cerebellum, significant activations during remote memory retrieval are limited to the piriform cortex. These results strongly support the view that amygdala-dependent memories also undergo system-level reorganization, and that sensory cortical areas might participate in the long-term storage of emotional memories.
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Affiliation(s)
- Anne-Marie Mouly
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Bron Cedex 69675, France
| | | | | | - Luc Zimmer
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Bron Cedex 69675, France.,CERMEP-Life Imaging, Bron Cedex 69677, France.,Hospices Civils de Lyon, Lyon 69002, France
| | - Nadine Ravel
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Bron Cedex 69675, France
| | - Philippe Litaudon
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Bron Cedex 69675, France
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90
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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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91
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McCool BA. Ethanol modulation of cortico-basolateral amygdala circuits: Neurophysiology and behavior. Neuropharmacology 2021; 197:108750. [PMID: 34371080 DOI: 10.1016/j.neuropharm.2021.108750] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/22/2021] [Accepted: 08/05/2021] [Indexed: 12/19/2022]
Abstract
This review highlights literature relating the anatomy, physiology, and behavioral contributions by projections between rodent prefrontal cortical areas and the basolateral amygdala. These projections are robustly modulated by both environmental experience and exposure to drugs of abuse including ethanol. Recent literature relating optogenetic and chemogenetic dissection of these circuits within behavior both compliments and occasionally challenges roles defined by more traditional pharmacological or lesion-based approaches. In particular, cortico-amygdala circuits help control both aversive and reward-seeking. Exposure to pathology-producing environments or abused drugs dysregulates the relative 'balance' of these outcomes. Modern circuit-based approaches have also shown that overlapping populations of neurons within a given brain region frequently govern both aversion and reward-seeking. In addition, these circuits often dramatically influence 'local' cortical or basolateral amygdala excitatory or inhibitory circuits. Our understanding of these neurobiological processes, particularly in relation to ethanol research, has just begun and represents a significant opportunity.
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Affiliation(s)
- Brian A McCool
- Department of Physiology & Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA.
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92
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Chen YH, Wu JL, Hu NY, Zhuang JP, Li WP, Zhang SR, Li XW, Yang JM, Gao TM. Distinct projections from the infralimbic cortex exert opposing effects in modulating anxiety and fear. J Clin Invest 2021; 131:e145692. [PMID: 34263737 DOI: 10.1172/jci145692] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 06/03/2021] [Indexed: 01/07/2023] Open
Abstract
Anxiety-related disorders can be treated by cognitive therapies and transcranial magnetic stimulation, which involve the medial prefrontal cortex (mPFC). Subregions of the mPFC have been implicated in mediating different and even opposite roles in anxiety-related behaviors. However, precise causal targets of these top-down connections among diverse possibilities have not been established. Here, we show that the lateral septum (LS) and the central nucleus of the amygdala (CeA) represent 2 direct targets of the infralimbic cortex (IL), a subregion of the mPFC that modulates anxiety and fear. Two projections were unexpectedly found to exert opposite effects on the anxious state and learned freezing: the IL-LS projection promoted anxiety-related behaviors and fear-related freezing, whereas the IL-CeA projection exerted anxiolytic and fear-releasing effects for the same features. Furthermore, selective inhibition of corresponding circuit elements showed opposing behavioral effects compared with excitation. Notably, the IL-CeA projection implemented top-down control of the stress-induced high-anxiety state. These results suggest that distinct IL outputs exert opposite effects in modulating anxiety and fear and that modulating the excitability of these projections with distinct strategies may be beneficial for the treatment of anxiety disorders.
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93
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Castillo-Ocampo Y, Colón M, Hernández A, Lopez P, Gerena Y, Porter JT. Plasticity of GluN1 at Ventral Hippocampal Synapses in the Infralimbic Cortex. Front Synaptic Neurosci 2021; 13:695964. [PMID: 34335223 PMCID: PMC8320376 DOI: 10.3389/fnsyn.2021.695964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/25/2021] [Indexed: 11/25/2022] Open
Abstract
Although the infralimbic cortex (IL) is not thought to play a role in fear acquisition, recent experiments found evidence that synaptic plasticity is occurring at ventral hippocampal (vHPC) synapses in IL during auditory fear acquisition as measured by changes in the N-methyl-D-aspartate (NMDA) receptor-mediated currents in male rats. These electrophysiological data suggest that fear conditioning changes the expression of NMDA receptors on vHPC-to-IL synapses. To further evaluate the plasticity of NMDA receptors at this specific synapse, we injected AAV particles expressing channelrhodopsin-EYFP into the vHPC of male and female rats to label vHPC projections with EYFP. To test for NMDA receptor changes in vHPC-to-IL synapses after fear learning, we used fluorescence-activated cell sorting (FACS) to quantify synaptosomes isolated from IL tissue punches that were positive for EYFP and the obligatory GluN1 subunit. More EYFP+/GluN1+ synaptosomes with greater average expression of GluN1 were isolated from male rats exposed to auditory fear conditioning (AFC) than those exposed to context and tones only or to contextual fear conditioning (CFC), suggesting that AFC increased NMDA receptor expression in males. In a second experiment, we found that pairing the tones and shocks was required to induce the molecular changes and that fear extinction did not reverse the changes. In contrast, females showed similar levels of EYFP+/GluN1+ synaptosomes in all behavioral groups. These findings suggest that AFC induces synaptic plasticity of NMDA receptors in the vHPC-to-IL projection in males, while female rats rely on different synaptic mechanisms.
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Affiliation(s)
- Yesenia Castillo-Ocampo
- Department of Basic Sciences, Ponce Research Institute, Ponce Health Sciences University, Ponce, Puerto Rico
| | - María Colón
- Department of Basic Sciences, Ponce Research Institute, Ponce Health Sciences University, Ponce, Puerto Rico
| | - Anixa Hernández
- Department of Basic Sciences, Ponce Research Institute, Ponce Health Sciences University, Ponce, Puerto Rico
| | - Pablo Lopez
- Department of Basic Sciences, Ponce Research Institute, Ponce Health Sciences University, Ponce, Puerto Rico
| | - Yamil Gerena
- Department of Pharmacology and Toxicology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - James T. Porter
- Department of Basic Sciences, Ponce Research Institute, Ponce Health Sciences University, Ponce, Puerto Rico
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94
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Loewke AC, Minerva AR, Nelson AB, Kreitzer AC, Gunaydin LA. Frontostriatal Projections Regulate Innate Avoidance Behavior. J Neurosci 2021; 41:5487-5501. [PMID: 34001628 PMCID: PMC8221601 DOI: 10.1523/jneurosci.2581-20.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 04/13/2021] [Accepted: 04/16/2021] [Indexed: 11/21/2022] Open
Abstract
The dorsomedial prefrontal cortex (dmPFC) has been linked to avoidance and decision-making under conflict, key neural computations altered in anxiety disorders. However, the heterogeneity of prefrontal projections has obscured identification of specific top-down projections involved. While the dmPFC-amygdala circuit has long been implicated in controlling reflexive fear responses, recent work suggests that dmPFC-dorsomedial striatum (DMS) projections may be more important for regulating avoidance. Using fiber photometry recordings in both male and female mice during the elevated zero maze task, we show heightened neural activity in frontostriatal but not frontoamygdalar projection neurons during exploration of the anxiogenic open arms. Additionally, using optogenetics, we demonstrate that this frontostriatal projection preferentially excites postsynaptic D1 receptor-expressing neurons in the DMS and causally controls innate avoidance behavior. These results support a model for prefrontal control of defensive behavior in which the dmPFC-amygdala projection controls reflexive fear behavior and the dmPFC-striatum projection controls anxious avoidance behavior.SIGNIFICANCE STATEMENT The medial prefrontal cortex has been extensively linked to several behavioral symptom domains related to anxiety disorders, with much of the work centered around reflexive fear responses. Comparatively little is known at the mechanistic level about anxious avoidance behavior, a core feature across anxiety disorders. Recent work has suggested that the striatum may be an important hub for regulating avoidance behaviors. Our work uses optical circuit dissection techniques to identify a specific corticostriatal circuit involved in encoding and controlling avoidance behavior. Identifying neural circuits for avoidance will enable the development of more targeted symptom-specific treatments for anxiety disorders.
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Affiliation(s)
- Adrienne C Loewke
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California 94158
| | - Adelaide R Minerva
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California 94158
| | - Alexandra B Nelson
- Department of Neurology, University of California, San Francisco, San Francisco, California 94158
- Kavli Institute for Fundamental Neuroscience is at University of California, San Francisco, San Francisco, California 94158
| | - Anatol C Kreitzer
- Department of Neurology, University of California, San Francisco, San Francisco, California 94158
- Kavli Institute for Fundamental Neuroscience is at University of California, San Francisco, San Francisco, California 94158
- Department of Physiology, University of California, San Francisco, San Francisco, California 94158
- Neurological Disease Institute, Gladstone Institutes, San Francisco, California 94158
| | - Lisa A Gunaydin
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California 94158
- Kavli Institute for Fundamental Neuroscience is at University of California, San Francisco, San Francisco, California 94158
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, California 94158
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95
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Omura J, Fuchikami M, Araki M, Miyagi T, Okamoto Y, Morinobu S. Chemogenetic activation of the mPFC alleviates impaired fear memory extinction in an animal model of PTSD. Prog Neuropsychopharmacol Biol Psychiatry 2021; 108:110090. [PMID: 32896603 DOI: 10.1016/j.pnpbp.2020.110090] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 08/19/2020] [Accepted: 08/30/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND AND AIM Although impaired extinction of fear memory (EFM) is a hallmark symptom of posttraumatic stress disorder (PTSD), the mechanisms underlying the impairment are unknown. Activation of the infralimbic cortex (IL) in the medial prefrontal cortex (mPFC) has been reported to predict successful fear extinction, whereas functionally disrupting this region impairs extinction. We examined whether chemogenetic activation of the IL could alleviate impaired EFM in a single prolonged stress (SPS) rat model of PTSD. METHODS Chemogenetic activation of IL and prelimbic (PL) excitatory neurons was undertaken to evaluate EFM using a contextual fear conditioning paradigm. Neuronal activity in the IL was recorded using a 32-multichannel silicon electrode. To examine histological changes in the mPFC, apoptosis was measured by TUNEL staining. RESULTS Chemogenetic activation of excitatory neurons in the IL, but not the PL, enhanced EFM in sham rats and resulted in alleviation of EFM impairment in SPS rats. The alleviation of impaired EFM in SPS rats was observed during the extinction test session. Neuronal activity in the IL of SPS rats was lower than that of sham rats after clozapine-n-oxide administration. Increased apoptosis was found in the IL of SPS rats. CONCLUSIONS These findings suggest that a decreased excitatory response in the IL due, at least in part, to an increase in apoptosis in SPS rats leads to impaired EFM, and that neuronal activation during extinction training could be useful for the treatment of impaired EFM in PTSD patients.
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Affiliation(s)
- Jun Omura
- Department of Psychiatry and Neuroscience, Division of Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Manabu Fuchikami
- Department of Psychiatry and Neuroscience, Division of Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
| | - Motoaki Araki
- Department of Psychiatry and Neuroscience, Division of Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tatsuhiro Miyagi
- Department of Psychiatry and Neuroscience, Division of Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yasumasa Okamoto
- Department of Psychiatry and Neuroscience, Division of Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Shigeru Morinobu
- Department of Occupational Therapy, School of Health Science and Social Welfare, Kibi International University, Takahashi, Japan
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96
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Memories are not written in stone: Re-writing fear memories by means of non-invasive brain stimulation and optogenetic manipulations. Neurosci Biobehav Rev 2021; 127:334-352. [PMID: 33964307 DOI: 10.1016/j.neubiorev.2021.04.036] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/29/2021] [Accepted: 04/29/2021] [Indexed: 11/21/2022]
Abstract
The acquisition of fear associative memory requires brain processes of coordinated neural activity within the amygdala, prefrontal cortex (PFC), hippocampus, thalamus and brainstem. After fear consolidation, a suppression of fear memory in the absence of danger is crucial to permit adaptive coping behavior. Acquisition and maintenance of fear extinction critically depend on amygdala-PFC projections. The robust correspondence between the brain networks encompassed cortical and subcortical hubs involved into fear processing in humans and in other species underscores the potential utility of comparing the modulation of brain circuitry in humans and animals, as a crucial step to inform the comprehension of fear mechanisms and the development of treatments for fear-related disorders. The present review is aimed at providing a comprehensive description of the literature on recent clinical and experimental researches regarding the noninvasive brain stimulation and optogenetics. These innovative manipulations applied over specific hubs of fear matrix during fear acquisition, consolidation, reconsolidation and extinction allow an accurate characterization of specific brain circuits and their peculiar interaction within the specific fear processing.
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97
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Maglio LE, Noriega-Prieto JA, Maroto IB, Martin-Cortecero J, Muñoz-Callejas A, Callejo-Móstoles M, Fernández de Sevilla D. IGF-1 facilitates extinction of conditioned fear. eLife 2021; 10:e67267. [PMID: 33792539 PMCID: PMC8043742 DOI: 10.7554/elife.67267] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/31/2021] [Indexed: 11/26/2022] Open
Abstract
Insulin-like growth factor-1 (IGF-1) plays a key role in synaptic plasticity, spatial learning, and anxiety-like behavioral processes. While IGF-1 regulates neuronal firing and synaptic transmission in many areas of the central nervous system, its signaling and consequences on excitability, synaptic plasticity, and animal behavior dependent on the prefrontal cortex remain unexplored. Here, we show that IGF-1 induces a long-lasting depression of the medium and slow post-spike afterhyperpolarization (mAHP and sAHP), increasing the excitability of layer 5 pyramidal neurons of the rat infralimbic cortex. Besides, IGF-1 mediates a presynaptic long-term depression of both inhibitory and excitatory synaptic transmission in these neurons. The net effect of this IGF-1-mediated synaptic plasticity is a long-term potentiation of the postsynaptic potentials. Moreover, we demonstrate that IGF-1 favors the fear extinction memory. These results show novel functional consequences of IGF-1 signaling, revealing IGF-1 as a key element in the control of the fear extinction memory.
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Affiliation(s)
- Laura E Maglio
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de MadridMadridSpain
- Departamento de Ciencias Médicas Básicas (Fisiología) and Instituto de Tecnologías Biomédicas (ITB), Universidad de La LagunaTenerifeSpain
| | - José A Noriega-Prieto
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de MadridMadridSpain
- Department of Neuroscience, University of MinnesotaMinneapolisUnited States
| | - Irene B Maroto
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de MadridMadridSpain
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto Universitario de Investigación Neuroquímica (IUIN), Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) and Departamento de Bioquímica y Biología Molecular, Facultad de Química, Universidad Complutense de MadridMadridSpain
| | - Jesús Martin-Cortecero
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de MadridMadridSpain
- Institute of Physiology and Pathophysiology, Medical Biophysic, Heidelberg UniversityHeidelbergGermany
| | - Antonio Muñoz-Callejas
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de MadridMadridSpain
| | - Marta Callejo-Móstoles
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de MadridMadridSpain
| | - David Fernández de Sevilla
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de MadridMadridSpain
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98
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Bouton ME, Maren S, McNally GP. BEHAVIORAL AND NEUROBIOLOGICAL MECHANISMS OF PAVLOVIAN AND INSTRUMENTAL EXTINCTION LEARNING. Physiol Rev 2021; 101:611-681. [PMID: 32970967 PMCID: PMC8428921 DOI: 10.1152/physrev.00016.2020] [Citation(s) in RCA: 153] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This article reviews the behavioral neuroscience of extinction, the phenomenon in which a behavior that has been acquired through Pavlovian or instrumental (operant) learning decreases in strength when the outcome that reinforced it is removed. Behavioral research indicates that neither Pavlovian nor operant extinction depends substantially on erasure of the original learning but instead depends on new inhibitory learning that is primarily expressed in the context in which it is learned, as exemplified by the renewal effect. Although the nature of the inhibition may differ in Pavlovian and operant extinction, in either case the decline in responding may depend on both generalization decrement and the correction of prediction error. At the neural level, Pavlovian extinction requires a tripartite neural circuit involving the amygdala, prefrontal cortex, and hippocampus. Synaptic plasticity in the amygdala is essential for extinction learning, and prefrontal cortical inhibition of amygdala neurons encoding fear memories is involved in extinction retrieval. Hippocampal-prefrontal circuits mediate fear relapse phenomena, including renewal. Instrumental extinction involves distinct ensembles in corticostriatal, striatopallidal, and striatohypothalamic circuits as well as their thalamic returns for inhibitory (extinction) and excitatory (renewal and other relapse phenomena) control over operant responding. The field has made significant progress in recent decades, although a fully integrated biobehavioral understanding still awaits.
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Affiliation(s)
- Mark E Bouton
- Department of Psychological Science, University of Vermont, Burlington, Vermont
| | - Stephen Maren
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, Texas
| | - Gavan P McNally
- School of Psychology, University of New South Wales, Sydney, Australia
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99
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Marković V, Vicario CM, Yavari F, Salehinejad MA, Nitsche MA. A Systematic Review on the Effect of Transcranial Direct Current and Magnetic Stimulation on Fear Memory and Extinction. Front Hum Neurosci 2021; 15:655947. [PMID: 33828472 PMCID: PMC8019721 DOI: 10.3389/fnhum.2021.655947] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 02/25/2021] [Indexed: 12/13/2022] Open
Abstract
Anxiety disorders are among the most prevalent mental disorders. Present treatments such as cognitive behavior therapy and pharmacological treatments show only moderate success, which emphasizes the importance for the development of new treatment protocols. Non-invasive brain stimulation methods such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) have been probed as therapeutic option for anxiety disorders in recent years. Mechanistic information about their mode of action, and most efficient protocols is however limited. Here the fear extinction model can serve as a model of exposure therapies for studying therapeutic mechanisms, and development of appropriate intervention protocols. We systematically reviewed 30 research articles that investigated the impact of rTMS and tDCS on fear memory and extinction in animal models and humans, in clinical and healthy populations. The results of these studies suggest that tDCS and rTMS can be efficient methods to modulate fear memory and extinction. Furthermore, excitability-enhancing stimulation applied over the vmPFC showed the strongest potential to enhance fear extinction. We further discuss factors that determine the efficacy of rTMS and tDCS in the context of the fear extinction model and provide future directions to optimize parameters and protocols of stimulation for research and treatment.
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Affiliation(s)
- Vuk Marković
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
- International Graduate School of Neuroscience, Ruhr-University-Bochum, Bochum, Germany
| | | | - Fatemeh Yavari
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
| | - Mohammad A. Salehinejad
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
| | - Michael A. Nitsche
- International Graduate School of Neuroscience, Ruhr-University-Bochum, Bochum, Germany
- Department of Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany
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100
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Jacobs DS, Moghaddam B. Medial prefrontal cortex encoding of stress and anxiety. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2021; 158:29-55. [PMID: 33785149 DOI: 10.1016/bs.irn.2020.11.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The prefrontal cortex (PFC) is involved in adaptive control of behavior and optimizing action selection. When an organism is experiencing an aversive event, such as a sustained state of anxiety or an overt experience of fear or stress, the mechanisms that govern PFC regulation of action selection may be critical for survival. A large body of literature has shown that acute aversive states influence the activity of PFC neurons and the release of neurotransmitters in this region. These states also result in long-term neurobiological changes in the PFC and expression of PFC-dependent motivated behaviors. The mechanism for how these changes lead to modifying action selection is only recently beginning to emerge. Here, we review animal and human studies into the neural mechanisms which may mediate the adaptive changes in the PFC that emerge during negative affective states. We then highlight recent advances in approaches for understanding how anxiety influences action selection and related cortical processes. We conclude by proposing that PFC neurons selectively influence action encoding during conditions where actions toward obtaining a reward or avoiding harm are executed under a fog of fear and anxiety.
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Affiliation(s)
- David S Jacobs
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, United States
| | - Bita Moghaddam
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, United States.
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