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Subramanian R, Bauman A, Carpenter O, Cho C, Coste G, Dam A, Drake K, Ehnstrom S, Fitzgerald N, Jenkins A, Koolpe H, Liu R, Paserman T, Petersen D, Chavez DS, Rozental S, Thompson H, Tsukuda T, Zweig S, Gall M, Zupan B, Bergstrom H. An Infralimbic Cortex Neuronal Ensemble Encoded During Learning Attenuates Fear Generalization Expression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.18.608308. [PMID: 39229064 PMCID: PMC11370439 DOI: 10.1101/2024.08.18.608308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Generalization allows for experience to flexibly guide behavior when conditions change. A basic physical unit of memory storage and expression in the brain are sparse, distributed groups of neurons known as ensembles (i.e., the engram). The infralimbic (IL) subregion of the ventral medial prefrontal cortex plays a key role in modulating conditioned defensive responses. How IL neuronal ensembles established during learning contribute to generalized responses is unknown. In this set of experiments, generalization was tested in male and female mice by presenting a novel, ambiguous, tone generalization stimulus following Pavlovian defensive (fear) conditioning. The first experiment was designed to test a role for IL in generalization using chemogenetic manipulations. Results show IL bidirectionally regulates defensive behavior. IL silencing promotes a switch in defensive state from vigilant scanning to generalized freezing, while IL stimulation reduces freezing in favor of scanning. Leveraging activity-dependent tagging technology (ArcCreERT2 x eYFP system), a neuronal ensemble, preferentially located in IL superficial layer 2/3, was associated with the generalization stimulus. Remarkably, in the identical discrete location, fewer reactivated neurons were associated with the generalization stimulus at the remote timepoint (30 days) following learning. When an IL neuronal ensemble established during learning was selectively chemogenetically silenced, generalization increased. Conversely, IL neuronal ensemble stimulation reduced generalization. Overall, these data identify a crucial role for IL in suppressing generalized responses. Further, we uncover an IL neuronal ensemble, formed during learning, functions to later attenuate the expression of generalization in the presence of ambiguous threat stimuli.
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Affiliation(s)
- Rajani Subramanian
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Avery Bauman
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Olivia Carpenter
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Chris Cho
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Gabrielle Coste
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Ahona Dam
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Kasey Drake
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Sara Ehnstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Naomi Fitzgerald
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Abigail Jenkins
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Hannah Koolpe
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Runqi Liu
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Tamar Paserman
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - David Petersen
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Diego Scala Chavez
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Stefano Rozental
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Hannah Thompson
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Tyler Tsukuda
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Sasha Zweig
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Megan Gall
- Department of Biology, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Bojana Zupan
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Hadley Bergstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
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Ma J, O'Malley JJ, Kreiker M, Leng Y, Khan I, Kindel M, Penzo MA. Convergent direct and indirect cortical streams shape avoidance decisions in mice via the midline thalamus. Nat Commun 2024; 15:6598. [PMID: 39097600 PMCID: PMC11297946 DOI: 10.1038/s41467-024-50941-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 07/24/2024] [Indexed: 08/05/2024] Open
Abstract
Current concepts of corticothalamic organization in the mammalian brain are mainly based on sensory systems, with less focus on circuits for higher-order cognitive functions. In sensory systems, first-order thalamic relays are driven by subcortical inputs and modulated by cortical feedback, while higher-order relays receive strong excitatory cortical inputs. The applicability of these principles beyond sensory systems is uncertain. We investigated mouse prefronto-thalamic projections to the midline thalamus, revealing distinct top-down control. Unlike sensory systems, this pathway relies on indirect modulation via the thalamic reticular nucleus (TRN). Specifically, the prelimbic area, which influences emotional and motivated behaviors, impacts instrumental avoidance responses through direct and indirect projections to the paraventricular thalamus. Both pathways promote defensive states, but the indirect pathway via the TRN is essential for organizing avoidance decisions through disinhibition. Our findings highlight intra-thalamic circuit dynamics that integrate cortical cognitive signals and their role in shaping complex behaviors.
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Affiliation(s)
- Jun Ma
- Section on the Neural Circuits of Emotion and Motivation, National Institute of Mental Health, Bethesda, MD, USA
- Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, 221004, Xuzhou, China
| | - John J O'Malley
- Section on the Neural Circuits of Emotion and Motivation, National Institute of Mental Health, Bethesda, MD, USA
| | - Malaz Kreiker
- Section on the Neural Circuits of Emotion and Motivation, National Institute of Mental Health, Bethesda, MD, USA
| | - Yan Leng
- Section on the Neural Circuits of Emotion and Motivation, National Institute of Mental Health, Bethesda, MD, USA
| | - Isbah Khan
- Section on the Neural Circuits of Emotion and Motivation, National Institute of Mental Health, Bethesda, MD, USA
| | - Morgan Kindel
- Section on the Neural Circuits of Emotion and Motivation, National Institute of Mental Health, Bethesda, MD, USA
| | - Mario A Penzo
- Section on the Neural Circuits of Emotion and Motivation, National Institute of Mental Health, Bethesda, MD, USA.
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Laine MA, Greiner EM, Shansky RM. Sex differences in the rodent medial prefrontal cortex - What Do and Don't we know? Neuropharmacology 2024; 248:109867. [PMID: 38387553 DOI: 10.1016/j.neuropharm.2024.109867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/22/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
The prefrontal cortex, particularly its medial subregions (mPFC), mediates critical functions such as executive control, behavioral inhibition, and memory formation, with relevance for everyday functioning and psychopathology. Despite broad characterization of the mPFC in multiple model organisms, the extent to which mPFC structure and function vary according to an individual's sex is unclear - a knowledge gap that can be attributed to a historical bias for male subjects in neuroscience research. Recent efforts to consider sex as a biological variable in basic science highlight the great need to close this gap. Here we review the knowns and unknowns about how rodents categorized as male or female compare in mPFC neuroanatomy, pharmacology, as well as in aversive, appetitive, and goal- or habit-directed behaviors that recruit the mPFC. We propose that long-standing dogmatic concepts of mPFC structure and function may not remain supported when we move beyond male-only studies, and that empirical challenges to these dogmas are warranted. Additionally, we note some common pitfalls in this work. Most preclinical studies operationalize sex as a binary categorization, and while this approach has furthered the inclusion of non-male rodents it is not as such generalizable to what we know of sex as a multidimensional, dynamic variable. Exploration of sex variability may uncover both sex differences and sex similarities, but care must be taken in their interpretation. Including females in preclinical research needs to go beyond the investigation of sex differences, improving our knowledge of how this brain region and its subregions mediate behavior and health. This article is part of the Special Issue on "PFC circuit function in psychiatric disease and relevant models".
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Affiliation(s)
- M A Laine
- Department of Psychology, Northeastern University, Boston, MA, USA
| | - E M Greiner
- Department of Psychology, Northeastern University, Boston, MA, USA.
| | - R M Shansky
- Department of Psychology, Northeastern University, Boston, MA, USA
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Jaramillo JCM, Aitken CM, Lawrence AJ, Ryan PJ. Oxytocin-receptor-expressing neurons in the lateral parabrachial nucleus activate widespread brain regions predominantly involved in fluid satiation. J Chem Neuroanat 2024; 137:102403. [PMID: 38452468 DOI: 10.1016/j.jchemneu.2024.102403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/21/2024] [Accepted: 02/23/2024] [Indexed: 03/09/2024]
Abstract
Fluid satiation is an important signal and aspect of body fluid homeostasis. Oxytocin-receptor-expressing neurons (OxtrPBN) in the dorsolateral subdivision of the lateral parabrachial nucleus (dl LPBN) are key neurons which regulate fluid satiation. In the present study, we investigated brain regions activated by stimulation of OxtrPBN neurons in order to better characterise the fluid satiation neurocircuitry in mice. Chemogenetic activation of OxtrPBN neurons increased Fos expression (a proxy marker for neuronal activation) in known fluid-regulating brain nuclei, as well as other regions that have unclear links to fluid regulation and which are likely involved in regulating other functions such as arousal and stress relief. In addition, we analysed and compared Fos expression patterns between chemogenetically-activated fluid satiation and physiological-induced fluid satiation. Both models of fluid satiation activated similar brain regions, suggesting that the chemogenetic model of stimulating OxtrPBN neurons is a relevant model of physiological fluid satiation. A deeper understanding of this neural circuit may lead to novel molecular targets and creation of therapeutic agents to treat fluid-related disorders.
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Affiliation(s)
- Janine C M Jaramillo
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; The Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Connor M Aitken
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; The Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Andrew J Lawrence
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; The Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Philip J Ryan
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; The Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.
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Quave CB, Vasquez AM, Aquino-Miranda G, Bora EP, Chidomere CL, Zhang XO, Engelke DS, Do-Monte FH. Neural signatures of opioid-induced risk-taking behavior in the prelimbic prefrontal cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.05.578828. [PMID: 38370807 PMCID: PMC10871263 DOI: 10.1101/2024.02.05.578828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Opioid use disorder occurs alongside impaired risk-related decision-making, but the underlying neural correlates are unclear. We developed a novel approach-avoidance conflict model using a modified conditioned place preference paradigm to study neural signals of risky opioid seeking in the prefrontal cortex, a region implicated in executive decision making. Upon establishment of morphine conditioned place preference, rats underwent a subsequent conflict test in which fear-inducing cat odor was introduced in the previously drug-paired side of the apparatus. While the saline control group avoided the cat odor side, the morphine group maintained preference for the paired side despite the presence of cat odor. K-means clustering identified two subsets of morphine-treated rats that exhibited either persistent drug seeking (Risk-Takers) or increased avoidance (Risk-Avoiders) during conflict. Single-unit recordings from the prelimbic cortex (PL) revealed decreased neuronal firing rates upon acute morphine exposure in both Risk-Takers and Risk-Avoiders, but this firing rate suppression was absent after repeated administration. Risk-Avoiders also displayed distinct post-morphine excitation in PL which persisted across conditioning. During the preference test, subpopulations of PL neurons in all groups were either excited or inhibited when rats entered the paired side. Interestingly, while this inhibitory signal was lost during the subsequent conflict test in both saline and Risk-Avoider groups, these inhibitory responses persisted in Risk-Takers. Our results suggest that loss of PL inhibition after opioid conditioning is associated with the formation of contextual reward memory. Furthermore, persistent PL inhibitory signaling in the drug-associated context during conflict may underlie increased risk taking following opioid exposure.
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Affiliation(s)
- Cana B. Quave
- Dept. of Neurobiology & Anatomy, The University of Texas Health Science Center, Houston, TX 77030, USA
- McGovern Medical School at UTHealth Houston, The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Andres M. Vasquez
- Dept. of Neurobiology & Anatomy, The University of Texas Health Science Center, Houston, TX 77030, USA
- Dept. of Neuroscience, Rice University, Houston, TX 77005, USA
| | - Guillermo Aquino-Miranda
- Dept. of Neurobiology & Anatomy, The University of Texas Health Science Center, Houston, TX 77030, USA
| | - Esha P. Bora
- Dept. of Neurobiology & Anatomy, The University of Texas Health Science Center, Houston, TX 77030, USA
| | - Chinenye L. Chidomere
- Dept. of Neurobiology & Anatomy, The University of Texas Health Science Center, Houston, TX 77030, USA
- Dept. of Biomedical Engineering, University of Houston, Houston, TX 77204, USA
| | - Xu O. Zhang
- Dept. of Neurobiology & Anatomy, The University of Texas Health Science Center, Houston, TX 77030, USA
- McGovern Medical School at UTHealth Houston, The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Douglas S. Engelke
- Dept. of Neurobiology & Anatomy, The University of Texas Health Science Center, Houston, TX 77030, USA
| | - Fabricio H. Do-Monte
- Dept. of Neurobiology & Anatomy, The University of Texas Health Science Center, Houston, TX 77030, USA
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6
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Krueger JN, Patel NN, Shim K, Ng K, Sangha S. Conditioned inhibition of fear and reward in male and female rats. Neurobiol Learn Mem 2024; 208:107881. [PMID: 38135111 PMCID: PMC10922191 DOI: 10.1016/j.nlm.2023.107881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 11/24/2023] [Accepted: 12/19/2023] [Indexed: 12/24/2023]
Abstract
Stimuli in our environment are not always associated with an outcome. Some of these stimuli, depending on how they are presented, may gain inhibitory value or simply be ignored. If experienced in the presence of other cues predictive of appetitive or aversive outcomes, they typically gain inhibitory value and become predictive cues indicating the absence of appetitive or aversive outcomes. In this case, these cues are referred to as conditioned inhibitors. Here, male and female Long Evans rats underwent cue discrimination training where a reward cue was paired with sucrose, a fear cue with footshock, and an inhibitor cue resulted in neither sucrose or footshock. During a subsequent summation test for conditioned inhibition of fear and reward, the inhibitor cue was presented concurrently with the reward and fear cues without any outcome, intermixed with trials of reinforced reward and fear trials. Males showed significant conditioned inhibition of freezing, while females did not, which was not dependent on estrous. Both males and females showed significant conditioned inhibition of reward. During a retardation of fear acquisition test, the inhibitor was paired with footshock and both males and females showed delayed acquisition of fear. During a retardation of reward acquisition test, the inhibitor was paired with sucrose, and females showed delayed acquisition of reward, while males did not. In summary, males and females showed significant reward-fear-inhibitor cue discrimination, conditioned inhibition of reward, and retardation of fear acquisition. The main sex difference, which was not estrous-dependent, was the lack of conditioned inhibition of freezing in females. These data imply that while the inhibitor cue gained some inhibitory value in the females, the strength of this inhibitory value may not have been great enough to effectively downregulate freezing elicited by the fear cue.
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Affiliation(s)
- Jamie N Krueger
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA 47907
| | - Nupur N Patel
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA 47907
| | - Kevin Shim
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA 47907
| | - Ka Ng
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA 47907
| | - Susan Sangha
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA 47907; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA 46202.
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Felix-Ortiz AC, Terrell JM, Gonzalez C, Msengi HD, Boggan MB, Ramos AR, Magalhães G, Burgos-Robles A. Prefrontal Regulation of Safety Learning during Ethologically Relevant Thermal Threat. eNeuro 2024; 11:ENEURO.0140-23.2024. [PMID: 38272673 PMCID: PMC10903390 DOI: 10.1523/eneuro.0140-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 01/02/2024] [Accepted: 01/22/2024] [Indexed: 01/27/2024] Open
Abstract
Learning and adaptation during sources of threat and safety are critical mechanisms for survival. The prelimbic (PL) and infralimbic (IL) subregions of the medial prefrontal cortex (mPFC) have been broadly implicated in the processing of threat and safety. However, how these regions regulate threat and safety during naturalistic conditions involving thermal challenge still remains elusive. To examine this issue, we developed a novel paradigm in which adult mice learned that a particular zone that was identified with visuospatial cues was associated with either a noxious cold temperature ("threat zone") or a pleasant warm temperature ("safety zone"). This led to the rapid development of avoidance behavior when the zone was paired with cold threat or approach behavior when the zone was paired with warm safety. During a long-term test without further thermal reinforcement, mice continued to exhibit robust avoidance or approach to the zone of interest, indicating that enduring spatial-based memories were formed to represent the thermal threat and thermal safety zones. Optogenetic experiments revealed that neural activity in PL and IL was not essential for establishing the memory for the threat zone. However, PL and IL activity bidirectionally regulated memory formation for the safety zone. While IL activity promoted safety memory during normal conditions, PL activity suppressed safety memory especially after a stress pretreatment. Therefore, a working model is proposed in which balanced activity between PL and IL is favorable for safety memory formation, whereas unbalanced activity between these brain regions is detrimental for safety memory after stress.
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Affiliation(s)
- Ada C Felix-Ortiz
- Department of Neuroscience, Developmental, and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
| | - Jaelyn M Terrell
- Department of Neuroscience, Developmental, and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
| | - Carolina Gonzalez
- Department of Neuroscience, Developmental, and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
| | - Hope D Msengi
- Department of Neuroscience, Developmental, and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
| | - Miranda B Boggan
- Department of Neuroscience, Developmental, and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
| | - Angelica R Ramos
- Department of Neuroscience, Developmental, and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
| | - Gabrielle Magalhães
- Department of Neuroscience, Developmental, and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts 02215
| | - Anthony Burgos-Robles
- Department of Neuroscience, Developmental, and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, Texas 78249
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Rosas-Vidal LE, Naskar S, Mayo LM, Perini I, Altemus M, Engelbrektsson H, Jagasia P, Heilig M, Patel S. PREFRONTAL CORRELATES OF FEAR GENERALIZATION DURING ENDOCANNABINOID DEPLETION. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.30.577847. [PMID: 38352388 PMCID: PMC10862899 DOI: 10.1101/2024.01.30.577847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Maladaptive fear generalization is one of the hallmarks of trauma-related disorders. The endocannabinoid 2-arachidonoylglycerol (2-AG) is crucial for modulating anxiety, fear, and stress adaptation but its role in balancing fear discrimination versus generalization is not known. To address this, we used a combination of plasma endocannabinoid measurement and neuroimaging from a childhood maltreatment exposed and non-exposed mixed population combined with human and rodent fear conditioning models. Here we show that 2-AG levels are inversely associated with fear generalization at the behavioral level in both mice and humans. In mice, 2-AG depletion increases the proportion of neurons, and the similarity between neuronal representations, of threat-predictive and neutral stimuli within prelimbic prefrontal cortex ensembles. In humans, increased dorsolateral prefrontal cortical-amygdala resting state connectivity is inversely correlated with fear generalization. These data provide convergent cross-species evidence that 2-AG is a key regulator of fear generalization and suggest 2-AG deficiency could represent a trauma-related disorder susceptibility endophenotype.
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Affiliation(s)
- Luis E Rosas-Vidal
- Northwestern University, Feinberg School of Medicine, Department of Psychiatry and Behavioral Sciences, Chicago, IL
| | - Saptarnab Naskar
- Northwestern University, Feinberg School of Medicine, Department of Psychiatry and Behavioral Sciences, Chicago, IL
| | - Leah M Mayo
- Hotchkiss Brain Institute and Mathison Centre for Mental Health Research and Education, Department of Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Linköping University, Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping, Sweden
| | - Irene Perini
- Linköping University, Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping, Sweden
| | - Megan Altemus
- Vanderbilt University Medical Center, Department of Psychiatry and Behavioral Sciences, Nashville, TN
| | - Hilda Engelbrektsson
- Linköping University, Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping, Sweden
| | - Puja Jagasia
- Vanderbilt University Medical Center, Department of Psychiatry and Behavioral Sciences, Nashville, TN
| | - Markus Heilig
- Linköping University, Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping, Sweden
| | - Sachin Patel
- Northwestern University, Feinberg School of Medicine, Department of Psychiatry and Behavioral Sciences, Chicago, IL
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Cai Y, Ge J, Pan ZZ. The projection from dorsal medial prefrontal cortex to basolateral amygdala promotes behaviors of negative emotion in rats. Front Neurosci 2024; 18:1331864. [PMID: 38327845 PMCID: PMC10847313 DOI: 10.3389/fnins.2024.1331864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 01/10/2024] [Indexed: 02/09/2024] Open
Abstract
Brain circuits between medial prefrontal cortex (mPFC) and amygdala have been implicated in cortical control of emotion, especially anxiety. Studies in recent years focus on differential roles of subregions of mPFC and amygdala, and reciprocal pathways between mPFC and amygdala in regulation of emotional behaviors. It has been shown that, while the projection from ventral mPFC to basomedial amygdala has an anxiolytic effect, the reciprocal projections between dorsal mPFC (dmPFC) and basolateral amygdala (BLA) are generally involved in an anxiogenic effect in various conditions with increased anxiety. However, the function of the projection from dmPFC to BLA in regulation of general emotional behaviors under normal conditions remains unclear. In this study, we used optogenetic analysis to identify how this dmPFC-BLA pathway regulates various emotional behaviors in normal rats. We found that optogenetic stimulation of the dmPFC-BLA pathway promoted a behavioral state of negative emotion, increasing anxiety-like and depressive-like behaviors and producing aversive behavior of place avoidance. Conversely, optogenetic inhibition of this pathway produced opposite effects, reducing anxiety-like and depressive-like behaviors, and inducing behaviors of place preference of reward. These findings suggest that activity of the dmPFC-BLA pathway is sufficient to drive a negative emotion state and the mPFC-amygdala circuit is tonically active in cortical regulation of emotional behaviors.
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Affiliation(s)
| | | | - Zhizhong Z. Pan
- Department of Anesthesiology and Pain Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
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10
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Ng K, Pollock M, Escobedo A, Bachman B, Miyazaki N, Bartlett EL, Sangha S. Suppressing fear in the presence of a safety cue requires infralimbic cortical signaling to central amygdala. Neuropsychopharmacology 2024; 49:359-367. [PMID: 37188848 PMCID: PMC10724163 DOI: 10.1038/s41386-023-01598-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/23/2023] [Accepted: 04/27/2023] [Indexed: 05/17/2023]
Abstract
Stressful events can have lasting and impactful effects on behavior, especially by disrupting normal regulation of fear and reward processing. Accurate discrimination among environmental cues predicting threat, safety or reward adaptively guides behavior. Post-traumatic stress disorder (PTSD) represents a condition in which maladaptive fear persists in response to explicit safety-predictive cues that coincide with previously learned threat cues, but without threat being present. Since both the infralimbic cortex (IL) and amygdala have each been shown to be important for fear regulation to safety cues, we tested the necessity of specific IL projections to the basolateral amygdala (BLA) or central amygdala (CeA) during safety recall. Male Long Evans rats were used since prior work showed female Long Evans rats did not acquire the safety discrimination task used in this study. Here, we show the infralimbic projection to the central amygdala was necessary for suppressing fear cue-induced freezing in the presence of a learned safety cue, and the projection to the basolateral amygdala was not. The loss of discriminative fear regulation seen specifically during IL->CeA inhibition is similar to the behavioral disruption seen in PTSD individuals that fail to regulate fear in the presence of a safety cue.
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Affiliation(s)
- Ka Ng
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Michael Pollock
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Abraham Escobedo
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Brent Bachman
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Nanami Miyazaki
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Edward L Bartlett
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Susan Sangha
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA.
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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11
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Fitzgerald JM, Webb EK, Sangha S. Psychological and physiological correlates of stimulus discrimination in adults. Psychophysiology 2023; 60:e14327. [PMID: 37170664 PMCID: PMC10527767 DOI: 10.1111/psyp.14327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 03/20/2023] [Accepted: 04/12/2023] [Indexed: 05/13/2023]
Abstract
The discrimination of cues in the environment that signal danger ("fear cue") is important for survival but depends critically on the discernment of such cues from ones that pose no threat ("safety cues"). In rodents, we previously demonstrated the underlying neurobiological mechanisms that support fear versus safety discrimination and documented that these mechanisms extend to the discrimination of reward as well. While learning about reward is equally important for survival, it remains an under-studied area of research, particularly in human studies of conditional discrimination. In the present study, we translated our rodent task of fear reward and neutral discrimination (fear, reward, and neutral discrimination [FRND]) for use in humans. Undergraduate students (N = 53) completed the FRND while electrodermal activity was recorded. Skin conductance response (SCR) amplitude, a marker of arousal response, was derived for fear, reward, and neutral cues that signaled no outcome; critical trials assessed conditional discrimination using combined fear + neutral and reward + neutral cues. Participants provided likeability ratings for each cue type. Results demonstrated that participants rated reward cues the best, fear cues the worst, and neutral cues in between, while SCR amplitude was largest for fear and reward cues and lowest for neutral cues. SCR amplitudes were reduced for fear + neutral (compared to fear) and reward + neutral cues (compared to reward). Results demonstrate that the FRND is a useful paradigm for the assessment of psychological and physiological discrimination of fear and reward. Implications and directions for future work are discussed.
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Affiliation(s)
| | - E. Kate Webb
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts, USA
- Division of Depression and Anxiety, McLean Hospital, Belmont, Massachusetts, USA
| | - Susan Sangha
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA
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12
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den Bakker H, Van Dijck M, Sun JJ, Kloosterman F. Sharp-wave-ripple-associated activity in the medial prefrontal cortex supports spatial rule switching. Cell Rep 2023; 42:112959. [PMID: 37590137 DOI: 10.1016/j.celrep.2023.112959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 06/22/2023] [Accepted: 07/24/2023] [Indexed: 08/19/2023] Open
Abstract
Previous studies have highlighted an important role for hippocampal sharp-wave ripples in spatial alternation learning, as well as in modulating activity in the medial prefrontal cortex (mPFC). However, the direct influence of hippocampal sharp-wave ripples on mPFC activity during spatial alternation learning has not been investigated. Here, we train Long Evans rats on a three-arm radial maze to perform a sequence of alternations. Three alternation sequences needed to be learned, and while learning a sequence, the activity in the mPFC was inhibited either directly following sharp-wave ripples in the hippocampus (on-time condition) or with a randomized delay (delayed condition). In the on-time condition, the behavioral performance is significantly worse compared to the same animals in the delayed inhibition condition, as measured by a lower correct alternation performance and more perseverative behavior. This indicates that the activity in the mPFC directly following hippocampal sharp-wave ripples is necessary for spatial rule switching.
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Affiliation(s)
- Hanna den Bakker
- Neuro-Electronics Research Flanders, Leuven, Belgium; Brain & Cognition, KU Leuven, Leuven, Belgium
| | - Marie Van Dijck
- Neuro-Electronics Research Flanders, Leuven, Belgium; Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Jyh-Jang Sun
- Neuro-Electronics Research Flanders, Leuven, Belgium
| | - Fabian Kloosterman
- Neuro-Electronics Research Flanders, Leuven, Belgium; Brain & Cognition, KU Leuven, Leuven, Belgium.
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13
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Felix-Ortiz AC, Terrell JM, Gonzalez C, Msengi HD, Ramos AR, Boggan MB, Lopez-Pesina SM, Magalhães G, Burgos-Robles A. The infralimbic and prelimbic cortical areas bidirectionally regulate safety learning during normal and stress conditions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.05.539516. [PMID: 37205585 PMCID: PMC10187296 DOI: 10.1101/2023.05.05.539516] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Safety learning is a critical function for behavioral adaptation, environmental fitness, and mental health. Animal models have implicated the prelimbic (PL) and infralimbic (IL) subregions of the medial prefrontal cortex (mPFC) in safety learning. However, whether these regions differentially contribute to safety learning and how their contributions become affected by stress still remain poorly understood. In this study, we evaluated these issues using a novel semi-naturalistic mouse model for threat and safety learning. As mice navigated within a test arena, they learned that specific zones were associated with either noxious cold temperatures ("threat") or pleasant warm temperatures ("safety"). Optogenetic-mediated inhibition revealed critical roles for the IL and PL regions for selectively controlling safety learning during these naturalistic conditions. This form of safety learning was also highly susceptible to stress pre-exposure, and while IL inhibition mimicked the deficits produced by stress, PL inhibition fully rescued safety learning in stress-exposed mice. Collectively, these findings indicate that IL and PL bidirectionally regulate safety learning during naturalistic situations, with the IL region promoting this function and the PL region suppressing it, especially after stress. A model of balanced IL and PL activity is proposed as a fundamental mechanism for controlling safety learning.
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Affiliation(s)
- Ada C. Felix-Ortiz
- Department of Neuroscience, Developmental, and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
| | - Jaelyn M. Terrell
- Department of Neuroscience, Developmental, and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
| | - Carolina Gonzalez
- Department of Neuroscience, Developmental, and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
| | - Hope D. Msengi
- Department of Neuroscience, Developmental, and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
| | - Angelica R. Ramos
- Department of Neuroscience, Developmental, and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
- Department of Psychology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
| | - Miranda B. Boggan
- Department of Neuroscience, Developmental, and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
- Department of Psychology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
| | - Savannah M. Lopez-Pesina
- Department of Neuroscience, Developmental, and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
| | - Gabrielle Magalhães
- Department of Neuroscience, Developmental, and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, United States, 02215
| | - Anthony Burgos-Robles
- Department of Neuroscience, Developmental, and Regenerative Biology, University of Texas at San Antonio, San Antonio, TX, United States, 78249
- Brain Health Consortium, University of Texas at San Antonio, San Antonio, TX, United States, 78249
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14
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Ng KH, Sangha S. Encoding of conditioned inhibitors of fear in the infralimbic cortex. Cereb Cortex 2023; 33:5658-5670. [PMID: 36411540 PMCID: PMC10152082 DOI: 10.1093/cercor/bhac450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/23/2022] Open
Abstract
Cues in the environment signaling the absence of threat, i.e. safety, can influence both fear and reward-seeking behaviors. Heightened and maladaptive fear is associated with reduced activity in the medial prefrontal cortex. We have previously shown in male rats that the infralimbic (IL) prefrontal cortex is necessary for suppressing fear during a safety cue. The objective of the present study was to determine if there was safety cue-specific neural activity within the IL using a Pavlovian conditioning paradigm, where a fear cue was paired with shock, a safety cue was paired with no shock, and a reward cue was paired with sucrose. To investigate how safety cues can suppress fear, the fear and safety cues were presented together as a compound fear + safety cue. Single-unit activity showed a large proportion of neurons with excitatory responses to the fear + safety cue specifically, a separate group of neurons with excitatory responses to both the reward and fear + safety cues, and bidirectional neurons with excitation to the fear + safety cue and inhibition to the fear cue. Neural activity was also found to be negatively correlated with freezing during the fear + safety cue. Together, these data implicate the IL in encoding specific aspects of conditioned inhibitors when fear is being actively suppressed.
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Affiliation(s)
- Ka H Ng
- Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907, United States
| | - Susan Sangha
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202, United States
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15
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Cassaday HJ, Muir C, Stevenson CW, Bonardi C, Hock R, Waite L. From safety to frustration: The neural substrates of inhibitory learning in aversive and appetitive conditioning procedures. Neurobiol Learn Mem 2023; 202:107757. [PMID: 37044368 DOI: 10.1016/j.nlm.2023.107757] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/20/2023] [Accepted: 04/08/2023] [Indexed: 04/14/2023]
Abstract
Inhibitory associative learning counters the effects of excitatory learning, whether appetitively or aversively motivated. Moreover, the affective responses accompanying the inhibitory associations are of opponent valence to the excitatory conditioned responses. Inhibitors for negative aversive outcomes (e.g. shock) signal safety, while inhibitors for appetitive outcomes (e.g. food reward) elicit frustration and/or disappointment. This raises the question as to whether studies using appetitive and aversive conditioning procedures should demonstrate the same neural substrates for inhibitory learning. We review the neural substrates of appetitive and aversive inhibitory learning as measured in different procedural variants and in the context of the underpinning excitatory conditioning on which it depends. The mesocorticolimbic dopamine pathways, retrosplenial cortex and hippocampus are consistently implicated in inhibitory learning. Further neural substrates identified in some procedural variants may be related to the specific motivation of the learning task and modalities of the learning cues. Finally, we consider the translational implications of our understanding of the neural substrates of inhibitory learning, for obesity and addictions as well as for anxiety disorders.
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Affiliation(s)
| | - C Muir
- School of Psychology, University of Nottingham; School of Physiology, Pharmacology, and Neuroscience, University of Bristol
| | | | - C Bonardi
- School of Psychology, University of Nottingham
| | - R Hock
- School of Psychology, University of Nottingham
| | - L Waite
- School of Psychology, University of Nottingham
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16
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Hackleman A, Ibrahim M, Shim K, Sangha S. Interaction of stress and alcohol on discriminating fear from safety and reward in male and female rats. Psychopharmacology (Berl) 2023; 240:609-621. [PMID: 35960326 PMCID: PMC9922333 DOI: 10.1007/s00213-022-06206-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 07/28/2022] [Indexed: 10/16/2022]
Abstract
RATIONALE Stressful events can have lasting and impactful effects on behavior, especially in terms of appropriate fear regulation and reward seeking. Our prior work in rats has shown baseline sex differences in fear expression and sucrose seeking in a discriminative reward-fear-safety conditioning task. OBJECTIVES The objectives of the current study were to determine how prior stress may affect alcohol consumption across a reward-fear-safety learning task, and how prior alcohol history may interact with stress to impact learning in this task. METHODS Male and female Long Evans rats were given home cage intermittent 24 h access to both water and alcohol for 5 weeks. A subset of rats then received exposure to stress (15 unsignaled footshocks), while remaining unstressed rats received context exposure without shock. One week later, all rats were trained on the same reward-fear-safety cue task while having continuous home cage access to both water and alcohol. RESULTS All rats increased consumption (g/kg/24 h) across the 5 weeks of intermittent access, with females showing higher consumption levels. Stress exposure did not alter alcohol consumption in the week following stress, but did increase home cage alcohol consumption during later reward-fear-safety cue learning. Stress in both sexes also elevated freezing levels to the reward cue resulting in decreased sucrose seeking and was positively correlated with home cage alcohol consumption. CONCLUSIONS While stress increased drinking in both males and females, the effects of stress were particularly pronounced in females, indicating our results could be capturing a higher propensity for females to display stress-induced drinking.
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Affiliation(s)
- Abigail Hackleman
- Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Muhja Ibrahim
- Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Kevin Shim
- Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Susan Sangha
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA. .,Department of Psychiatry, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, IN, NB 300A46202, USA.
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17
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Hilz EN, Lee HJ. Estradiol and progesterone in female reward-learning, addiction, and therapeutic interventions. Front Neuroendocrinol 2023; 68:101043. [PMID: 36356909 DOI: 10.1016/j.yfrne.2022.101043] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 09/24/2022] [Accepted: 10/28/2022] [Indexed: 11/09/2022]
Abstract
Sex steroid hormones like estradiol (E2) and progesterone (P4) guide the sexual organization and activation of the developing brain and control female reproductive behavior throughout the lifecycle; importantly, these hormones modulate functional activity of not just the endocrine system, but most of the nervous system including the brain reward system. The effects of E2 and P4 can be seen in the processing of and memory for rewarding stimuli and in the development of compulsive reward-seeking behaviors like those seen in substance use disorders. Women are at increased risk of developing substance use disorders; however, the origins of this sex difference are not well understood and therapeutic interventions targeting ovarian hormones have produced conflicting results. This article reviews the contribution of the E2 and P4 in females to functional modulation of the brain reward system, their possible roles in origins of addiction vulnerability, and the development and treatment of compulsive reward-seeking behaviors.
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Affiliation(s)
- Emily N Hilz
- The University of Texas at Austin, Department of Pharmacology, USA.
| | - Hongjoo J Lee
- The University of Texas at Austin, Department of Psychology, USA; The University of Texas at Austin, Institute for Neuroscience, USA
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18
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Lee JY, You T, Woo CW, Kim SG. Optogenetic fMRI for Brain-Wide Circuit Analysis of Sensory Processing. Int J Mol Sci 2022; 23:ijms232012268. [PMID: 36293125 PMCID: PMC9602603 DOI: 10.3390/ijms232012268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/12/2022] [Accepted: 10/12/2022] [Indexed: 11/20/2022] Open
Abstract
Sensory processing is a complex neurological process that receives, integrates, and responds to information from one's own body and environment, which is closely related to survival as well as neurological disorders. Brain-wide networks of sensory processing are difficult to investigate due to their dynamic regulation by multiple brain circuits. Optogenetics, a neuromodulation technique that uses light-sensitive proteins, can be combined with functional magnetic resonance imaging (ofMRI) to measure whole-brain activity. Since ofMRI has increasingly been used for investigating brain circuits underlying sensory processing for over a decade, we systematically reviewed recent ofMRI studies of sensory circuits and discussed the challenges of optogenetic fMRI in rodents.
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Affiliation(s)
- Jeong-Yun Lee
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 16419, Korea
| | - Taeyi You
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 16419, Korea
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, Korea
| | - Choong-Wan Woo
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 16419, Korea
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, Korea
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 16419, Korea
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, Korea
- Correspondence: ; Tel.: +82-31-299-4350; Fax: +82-31-299-4506
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19
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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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20
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Adkins JM, Halcomb CJ, Rogers D, Jasnow AM. Stress and sex-dependent effects on conditioned inhibition of fear. Learn Mem 2022; 29:246-255. [PMID: 36206391 PMCID: PMC9488025 DOI: 10.1101/lm.053508.121] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/10/2022] [Indexed: 10/14/2022]
Abstract
Anxiety and stress-related disorders are highly prevalent and are characterized by excessive fear to threatening and nonthreatening stimuli. Moreover, there is a large sex bias in vulnerability to anxiety and stress-related disorders-women make up a disproportionately larger number of affected individuals compared with men. Growing evidence suggests that an impaired ability to suppress fear in the presence of safety signals may in part contribute to the development and maintenance of many anxiety and stress-related disorders. However, the sex-dependent impact of stress on conditioned inhibition of fear remains unclear. The present study investigated sex differences in the acquisition and recall of conditioned inhibition in male and female mice with a focus on understanding how stress impacts fear suppression. In these experiments, the training context served as the "fear" cue and an explicit tone served as the "safety" cue. Here, we found a possible sex difference in the training requirements for safety learning, although this effect was not consistent across experiments. Reductions in freezing to the safety cue in female mice were also not due to alternative fear behavior expression such as darting. Next, using footshock as a stressor, we found that males were impaired in conditioned inhibition of freezing when the stress was experienced before, but not after, conditioned inhibition training. Females were unaffected by footshock stress when it was administered at either time. Extended conditioned inhibition training in males eliminated the deficit produced by footshock stress. Finally, exposing male and female mice to swim stress impaired safety learning in male mice only. Thus, we found sex × stress interactions in the learning of conditioned inhibition and sex-dependent effects of stress modality. The present study adds to the growing literature on sex differences in safety learning, which will be critical for developing sex-specific therapies for a variety of fear-related disorders that involve excessive fear and/or impaired fear inhibition.
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Affiliation(s)
- Jordan M Adkins
- Department of Psychological Sciences, Brain Health Research Institute, Kent State University, Kent, Ohio 44242, USA
| | - Carly J Halcomb
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina 29209, USA
| | - Danielle Rogers
- Department of Psychological Sciences, Brain Health Research Institute, Kent State University, Kent, Ohio 44242, USA
| | - Aaron M Jasnow
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina 29209, USA
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21
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Hamel L, Cavdaroglu B, Yeates D, Nguyen D, Riaz S, Patterson D, Khan N, Kirolos N, Roper K, Ha QA, Ito R. Cortico-Striatal Control over Adaptive Goal-Directed Responding Elicited by Cues Signaling Sucrose Reward or Punishment. J Neurosci 2022; 42:3811-3822. [PMID: 35351827 PMCID: PMC9087743 DOI: 10.1523/jneurosci.2175-21.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 03/21/2022] [Accepted: 03/23/2022] [Indexed: 11/21/2022] Open
Abstract
The medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) have been associated with the expression of adaptive and maladaptive behavior elicited by fear-related and drug-associated cues. However, reported effects of mPFC manipulations on cue-elicited natural reward-seeking and inhibition thereof have been varied, with few studies examining cortico-striatal contributions in tasks that require adaptive responding to cues signaling reward and punishment within the same session. The current study aimed to better elucidate the role of mPFC and NAc subdivisions, and their functional connectivity in cue-elicited adaptive responding using a novel discriminative cue responding task. Male Long-Evans rats learned to lever-press on a VR5 schedule for a discriminative cue signaling reward, and to avoid pressing the same lever in the presence of another cue signaling punishment. Postacquisition, prelimbic (PL) and infralimbic (IL) areas of the mPFC, NAc core, shell, PL-core, or IL-shell circuits were pharmacologically or chemogenetically inhibited while animals performed under (1) nonreinforced (extinction) conditions, where the appetitive and aversive cues were presented in alternating trials alone or as a compound stimulus; and (2) reinforced conditions, whereby cued responding was accompanied by associated outcomes. PL and IL inactivation attenuated nonreinforced and reinforced goal-directed cue responding, whereas NAc core and shell inactivation impaired nonreinforced responding for the appetitive, but not aversive cue. Furthermore, PL-core and IL-shell inhibition disinhibited nonreinforced but not reinforced cue responding. Our findings implicate the mPFC as a site of confluence of motivationally significant cues and outcomes, and in the regulation of nonreinforced cue responding via downstream NAc targets.SIGNIFICANCE STATEMENT The ability to discriminate and respond appropriately to environmental cues that signal availability of reward or punishment is essential for survival. The medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) have been implicated in adaptive and maladaptive behavior elicited by fear-related and drug-associated cues. However, less is known about the role they play in orchestrating adaptive responses to natural reward and punishment cues within the same behavioral task. Here, using a novel discriminative cue responding task combined with pharmacological or chemogenetic inhibition of mPFC, NAc and mPFC-NAc circuits, we report that mPFC is critically involved in responding to changing cued response-outcomes, both when the responses are reinforced, and nonreinforced. Furthermore, the mPFC coordinates nonreinforced discriminative cue responding by suppressing inappropriate responding via downstream NAc targets.
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Affiliation(s)
- Laurie Hamel
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
| | - Bilgehan Cavdaroglu
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
| | - Dylan Yeates
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
| | - David Nguyen
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
| | - Sadia Riaz
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
| | - Dylan Patterson
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3G5 Canada
| | - Nisma Khan
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
| | - Nardin Kirolos
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
| | - Katherine Roper
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
| | - Quynh An Ha
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
| | - Rutsuko Ito
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario, M1C 1A4, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3G5 Canada
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22
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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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23
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Hughes RB, Whittingham-Dowd J, Clapcote SJ, Broughton SJ, Dawson N. Altered medial prefrontal cortex and dorsal raphé activity predict genotype and correlate with abnormal learning behavior in a mouse model of autism-associated 2p16.3 deletion. Autism Res 2022; 15:614-627. [PMID: 35142069 PMCID: PMC9303357 DOI: 10.1002/aur.2685] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 01/14/2022] [Accepted: 01/24/2022] [Indexed: 12/26/2022]
Abstract
2p16.3 deletion, involving NEUREXIN1 (NRXN1) heterozygous deletion, substantially increases the risk of developing autism and other neurodevelopmental disorders. We have a poor understanding of how NRXN1 heterozygosity impacts on brain function and cognition to increase the risk of developing the disorder. Here we characterize the impact of Nrxn1α heterozygosity on cerebral metabolism, in mice, using 14C‐2‐deoxyglucose imaging. We also assess performance in an olfactory‐based discrimination and reversal learning (OB‐DaRL) task and locomotor activity. We use decision tree classifiers to test the predictive relationship between cerebral metabolism and Nrxn1α genotype. Our data show that Nrxn1α heterozygosity induces prefrontal cortex (medial prelimbic cortex, mPrL) hypometabolism and a contrasting dorsal raphé nucleus (DRN) hypermetabolism. Metabolism in these regions allows for the predictive classification of Nrxn1α genotype. Consistent with reduced mPrL glucose utilization, prefrontal cortex insulin receptor signaling is decreased in Nrxn1α+/− mice. Behaviorally, Nrxn1α+/− mice show enhanced learning of a novel discrimination, impaired reversal learning and an increased latency to make correct choices. In addition, male Nrxn1α+/− mice show hyperlocomotor activity. Correlative analysis suggests that mPrL hypometabolism contributes to the enhanced novel odor discrimination seen in Nrxn1α+/− mice, while DRN hypermetabolism contributes to their increased latency in making correct choices. The data show that Nrxn1α heterozygosity impacts on prefrontal cortex and serotonin system function, which contribute to the cognitive alterations seen in these animals. The data suggest that Nrxn1α+/− mice provide a translational model for the cognitive and behavioral alterations seen in autism and other neurodevelopmental disorders associated with 2p16.3 deletion.
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Affiliation(s)
- Rebecca B Hughes
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
| | - Jayde Whittingham-Dowd
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
| | | | - Susan J Broughton
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
| | - Neil Dawson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
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24
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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: 36] [Impact Index Per Article: 18.0] [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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25
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Fernandez-Leon JA, Engelke DS, Aquino-Miranda G, Goodson A, Rasheed MN, Do Monte FH. Neural correlates and determinants of approach-avoidance conflict in the prelimbic prefrontal cortex. eLife 2021; 10:74950. [PMID: 34913438 PMCID: PMC8853658 DOI: 10.7554/elife.74950] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 12/13/2021] [Indexed: 12/04/2022] Open
Abstract
The recollection of environmental cues associated with threat or reward allows animals to select the most appropriate behavioral responses. Neurons in the prelimbic (PL) cortex respond to both threat- and reward-associated cues. However, it remains unknown whether PL regulates threat-avoidance vs. reward-approaching responses when an animals’ decision depends on previously associated memories. Using a conflict model in which male Long–Evans rats retrieve memories of shock- and food-paired cues, we observed two distinct phenotypes during conflict: (1) rats that continued to press a lever for food (Pressers) and (2) rats that exhibited a complete suppression in food seeking (Non-pressers). Single-unit recordings revealed that increased risk-taking behavior in Pressers is associated with persistent food-cue responses in PL, and reduced spontaneous activity in PL glutamatergic (PLGLUT) neurons during conflict. Activating PLGLUT neurons in Pressers attenuated food-seeking responses in a neutral context, whereas inhibiting PLGLUT neurons in Non-pressers reduced defensive responses and increased food approaching during conflict. Our results establish a causal role for PLGLUT neurons in mediating individual variability in memory-based risky decision-making by regulating threat-avoidance vs. reward-approach behaviors.
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Affiliation(s)
| | - Douglas S Engelke
- Department of Neurobiology and Anatomy, The University of Texas Health Science Center at Houston, Houston, United States
| | - Guillermo Aquino-Miranda
- Department of Neurobiology and Anatomy, The University of Texas Health Science Center at Houston, Houston, United States
| | | | - Maria N Rasheed
- Department of Neurobiology and Anatomy, The University of Texas Health Science Center at Houston, Houston, United States
| | - Fabricio H Do Monte
- Department of Neurobiology and Anatomy, The University of Texas Health Science Center at Houston, Houston, United States
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26
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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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27
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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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28
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Lucantonio F, Kim E, Su Z, Chang AJ, Bari BA, Cohen JY. Aversive stimuli bias corticothalamic responses to motivationally significant cues. eLife 2021; 10:57634. [PMID: 34738905 PMCID: PMC8570692 DOI: 10.7554/elife.57634] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 10/11/2021] [Indexed: 11/19/2022] Open
Abstract
Making predictions about future rewards or punishments is fundamental to adaptive behavior. These processes are influenced by prior experience. For example, prior exposure to aversive stimuli or stressors changes behavioral responses to negative- and positive-value predictive cues. Here, we demonstrate a role for medial prefrontal cortex (mPFC) neurons projecting to the paraventricular nucleus of the thalamus (PVT; mPFC→PVT) in this process. We found that a history of aversive stimuli negatively biased behavioral responses to motivationally relevant cues in mice and that this negative bias was associated with hyperactivity in mPFC→PVT neurons during exposure to those cues. Furthermore, artificially mimicking this hyperactive response with selective optogenetic excitation of the same pathway recapitulated the negative behavioral bias induced by aversive stimuli, whereas optogenetic inactivation of mPFC→PVT neurons prevented the development of the negative bias. Together, our results highlight how information flow within the mPFC→PVT circuit is critical for making predictions about motivationally-relevant outcomes as a function of prior experience.
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Affiliation(s)
- Federica Lucantonio
- The Solomon H Snyder Department of Neuroscience, Brain Science Institute, Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Eunyoung Kim
- The Solomon H Snyder Department of Neuroscience, Brain Science Institute, Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Zhixiao Su
- The Solomon H Snyder Department of Neuroscience, Brain Science Institute, Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Anna J Chang
- The Solomon H Snyder Department of Neuroscience, Brain Science Institute, Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Bilal A Bari
- The Solomon H Snyder Department of Neuroscience, Brain Science Institute, Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Jeremiah Y Cohen
- The Solomon H Snyder Department of Neuroscience, Brain Science Institute, Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
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29
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Chen Y, Lu X, Yu P, Zeng L, Ye H, Shi Q, Guo W. Modulating the Activity of the VMPFC With tDCS Alters the Social Framing Effect. Front Behav Neurosci 2021; 15:677006. [PMID: 34512282 PMCID: PMC8426551 DOI: 10.3389/fnbeh.2021.677006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 07/23/2021] [Indexed: 12/30/2022] Open
Abstract
Numerous experimental studies have replicated the social framing effect-the observation that people’s decisions related to economic benefits and feelings depend on the method of presentation. Previous neuroimaging studies have shown that the ventromedial prefrontal cortex (VMPFC) plays a part in the influence of framing and how individuals think about the feelings of others. Based on this, we used transcranial direct current stimulation (tDCS) to modulate neuronal activity in the VMPFC to determine the likelihood of a direct association between VMPFC activity and the social framing effect. Subsequently, in three stimulation treatments, we assessed the presence of the social framing effect, as demonstrated by a disparity between harm degree and help degree. The findings revealed a social framing effect in the participants in the control group and the sham treatment but no social framing effect in the participants in the anodal or cathodal treatments. Furthermore, sex differences were observed in the sham treatment’s social framing effect, whereas no sex differences were observed in the anodal or cathodal treatments. The participants tended to harm the victim after receiving anodal or cathodal tDCS over the VMPFC and did not change their helping behaviour in any stimulations. Consequently, a clear causal link between the behaviour of the VMPFC and the social framing effect was found in the present research.
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Affiliation(s)
- Yuyou Chen
- Center for Economic Behavior and Decision-Making, Zhejiang University of Finance and Economics, Hangzhou, China.,School of Economics, Zhejiang University of Finance and Economics, Hangzhou, China
| | - Xinbo Lu
- School of Economics, Jiaxing University, Jiaxing, China
| | - Ping Yu
- Center for Economic Behavior and Decision-Making, Zhejiang University of Finance and Economics, Hangzhou, China.,School of Economics, Zhejiang University of Finance and Economics, Hangzhou, China
| | - Lulu Zeng
- Center for Economic Behavior and Decision-Making, Zhejiang University of Finance and Economics, Hangzhou, China.,School of Economics, Zhejiang University of Finance and Economics, Hangzhou, China
| | - Hang Ye
- Center for Economic Behavior and Decision-Making, Zhejiang University of Finance and Economics, Hangzhou, China.,School of Economics, Zhejiang University of Finance and Economics, Hangzhou, China
| | - Qing Shi
- School of Information Management and Artificial Intelligence, Zhejiang University of Finance and Economics, Hangzhou, China
| | - Wenmin Guo
- Center for Economic Behavior and Decision-Making, Zhejiang University of Finance and Economics, Hangzhou, China.,School of Economics, Zhejiang University of Finance and Economics, Hangzhou, China
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30
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De Falco E, White SM, Morningstar MD, Ma B, Nkurunziza LT, Ahmed‐Dilibe A, Wellman CL, Lapish CC. Impaired cognitive flexibility and heightened urgency are associated with increased alcohol consumption in rodent models of excessive drinking. Addict Biol 2021; 26:e13004. [PMID: 33508872 DOI: 10.1111/adb.13004] [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: 08/06/2020] [Revised: 11/10/2020] [Accepted: 12/20/2020] [Indexed: 10/22/2022]
Abstract
Alcohol use disorder (AUD) is characterized by impairments in decision-making that can exist as stable traits or transient states. Cognitive inflexibility reflects an inability to update information that guides decision-making and is thought to contribute to the inability to abstain from drinking. While several studies have reported evidence of impaired cognitive flexibility following chronic alcohol exposure, evidence that a pre-existing impairment in cognitive flexibility is a heritable risk factor for AUD is scarce. Here, we found that cognitive flexibility was impaired in rodents selectively bred for excessive alcohol consumption (alcohol preferring (P) rats), on the attentional set-shifting task (ASST). Further, the degree of impairment is predictive of future ethanol consumption, thus suggesting that cognitive inflexibility is a stable trait capable of predisposing one for drinking. In a second set of experiments, we observed an impairment in the ability of P rats to use a previously learned rule to guide foraging in a simple discrimination task. Convergence across several behavioral measures suggested that this impairment reflected a state of heightened urgency that interfered with decision-making. A similar impairment on a simple discrimination task was observed in Wistar rats with a history of alcohol consumption. These findings indicate how trait and state variables-in this case, impaired cognitive flexibility and heightened urgency, respectively-may influence the risk for excessive drinking. Furthermore, our results suggest that cognitive inflexibility and urgency can exist as both risk factors for and the result of alcohol exposure.
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Affiliation(s)
- Emanuela De Falco
- Department of Psychology Indiana University‐Purdue University Indianapolis Indianapolis IN USA
| | - Shelby M. White
- Department of Psychology Indiana University‐Purdue University Indianapolis Indianapolis IN USA
| | - Mitchell D. Morningstar
- Department of Psychology Indiana University‐Purdue University Indianapolis Indianapolis IN USA
| | - Baofeng Ma
- Department of Psychology Indiana University‐Purdue University Indianapolis Indianapolis IN USA
| | - Lionnel T. Nkurunziza
- Department of Psychology Indiana University‐Purdue University Indianapolis Indianapolis IN USA
| | - Anisah Ahmed‐Dilibe
- Department of Psychology Indiana University‐Purdue University Indianapolis Indianapolis IN USA
| | - Cara L. Wellman
- Department of Psychological & Brain Sciences Indiana University, Bloomington IN USA
| | - Christopher C. Lapish
- Department of Psychology Indiana University‐Purdue University Indianapolis Indianapolis IN USA
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31
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Soares VPMN, de Andrade TGCS, Canteras NS, Coimbra NC, Wotjak CT, Almada RC. Orexin 1 and 2 Receptors in the Prelimbic Cortex Modulate Threat Valuation. Neuroscience 2021; 468:158-167. [PMID: 34126185 DOI: 10.1016/j.neuroscience.2021.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/10/2021] [Accepted: 06/03/2021] [Indexed: 12/21/2022]
Abstract
The ability to distinguish between threatening (repulsors), neutral and appetitive stimuli (attractors) stimuli is essential for survival. The orexinergic neurons of hypothalamus send projections to the limbic structures, such as different subregions of the medial prefrontal cortex (mPFC), suggesting that the orexinergic mechanism in the prelimbic cortex (PL) is involved in the processing of fear and anxiety. We investigated the role of orexin receptors type 1 (OX1R) and type 2 (OX2R) in the PL in such processes upon confrontation with an erratically moving robo-beetle in mice. The selective blockade of OX1R and OX2R in the PL with SB 334867 (3, 30, 300 nM) and TCS OX2 29 (3, 30, 300 nM), respectively, did not affect general exploratory behavior or reactive fear such as avoidance, jumping or freezing, but significantly enhances tolerance and approach behavior at the highest dose of each antagonist tested (300 nM). We interpret these findings as evidence for an altered cognitive appraisal of the potential threatening stimulus. Consequently, the orexin system seems to bias the perception of stimuli towards danger or threat via OX1R and OX2R in the PL.
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Affiliation(s)
- Victor P M N Soares
- Department of Biological Sciences, School of Sciences, Humanities and Languages of the São Paulo State University (UNESP), Assis, São Paulo, Brazil
| | - Telma G C S de Andrade
- Department of Biological Sciences, School of Sciences, Humanities and Languages of the São Paulo State University (UNESP), Assis, São Paulo, Brazil
| | - Newton S Canteras
- Department of Anatomy, Biomedical Sciences Institute of the University of São Paulo (ICB-USP), São Paulo, São Paulo, Brazil
| | - Norberto C Coimbra
- Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil; Behavioural Neuroscience Institute (INeC), Ribeirão Preto, São Paulo, Brazil; NAP-USP-Neurobiology of Emotions Research Centre (NuPNE), Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Carsten T Wotjak
- Neuronal Plasticity Research Group, Max Planck Institute of Psychiatry, Munich, Germany; Central Nervous System Diseases Research, Boehringer Ingelheim Pharmaceuticals Die Gesellschaft mit Beschränkter Haftung & Compagnie Kommanditgesellschaft, Biberach Riss, Germany
| | - Rafael C Almada
- Department of Biological Sciences, School of Sciences, Humanities and Languages of the São Paulo State University (UNESP), Assis, São Paulo, Brazil; Behavioural Neuroscience Institute (INeC), Ribeirão Preto, São Paulo, Brazil.
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32
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Petrie GN, Nastase AS, Aukema RJ, Hill MN. Endocannabinoids, cannabinoids and the regulation of anxiety. Neuropharmacology 2021; 195:108626. [PMID: 34116110 DOI: 10.1016/j.neuropharm.2021.108626] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 05/11/2021] [Accepted: 05/24/2021] [Indexed: 12/16/2022]
Abstract
Cannabis has been used for hundreds of years, with its ability to dampen feelings of anxiety often reported as a primary reason for use. Only recently has the specific role cannabinoids play in anxiety been thoroughly investigated. Here we discuss the body of evidence describing how endocannabinoids and exogenous cannabinoids are capable of regulating the generation and termination of anxiety states. Disruption of the endogenous cannabinoid (eCB) system following genetic manipulation, pharmacological intervention or stress exposure reliably leads to the generation of an anxiety state. On the other hand, upregulation of eCB signaling is capable of alleviating anxiety-like behaviors in multiple paradigms. When considering exogenous cannabinoid administration, cannabinoid receptor 1 (CB1) agonists have a biphasic, dose-dependent effect on anxiety such that low doses are anxiolytic while high doses are anxiogenic, a phenomenon that is evident in both rodent models and humans. Translational studies investigating a loss of function mutation in the gene for fatty acid amide hydrolase, the enzyme responsible for metabolizing AEA, have also shown that AEA signaling regulates anxiety in humans. Taken together, evidence reviewed here has outlined a convincing argument for cannabinoids being powerful regulators of both the manifestation and amelioration of anxiety symptoms, and highlights the therapeutic potential of targeting the eCB system for the development of novel classes of anxiolytics. This article is part of the special issue on 'Cannabinoids'.
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Affiliation(s)
- Gavin N Petrie
- Hotchkiss Brain Institute and the Mathison Centre for Mental Health Education and Research, Departments of Cell Biology and Anatomy & Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Andrei S Nastase
- Hotchkiss Brain Institute and the Mathison Centre for Mental Health Education and Research, Departments of Cell Biology and Anatomy & Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Robert J Aukema
- Hotchkiss Brain Institute and the Mathison Centre for Mental Health Education and Research, Departments of Cell Biology and Anatomy & Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Matthew N Hill
- Hotchkiss Brain Institute and the Mathison Centre for Mental Health Education and Research, Departments of Cell Biology and Anatomy & Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 1N4, Canada.
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33
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Food-Seeking Behavior Is Mediated by Fos-Expressing Neuronal Ensembles Formed at First Learning in Rats. eNeuro 2021; 8:ENEURO.0373-20.2021. [PMID: 33472867 PMCID: PMC8174054 DOI: 10.1523/eneuro.0373-20.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 12/22/2020] [Accepted: 01/06/2021] [Indexed: 11/21/2022] Open
Abstract
Neuronal ensembles in the infralimbic cortex (IL) develop after prolonged food self-administration training. However, rats demonstrate evidence of learning the food self-administration response as early as day 1, with responding quickly increasing to asymptotic levels. Since the contribution of individual brain regions to task performance shifts over the course of training, it remains unclear whether IL ensembles are gradually formed and refined over the course of extensive operant training, or whether functionally-relevant ensembles might be recruited and formed as early as the initial acquisition of food self-administration behavior. Here, we aimed to determine the role of IL ensembles at the earliest possible point after demonstrable learning of a response-outcome association. We first allowed rats to lever press for palatable food pellets and stopped training rats once their behavior evidenced the response-outcome association (learners). We compared their food-seeking behavior and neuronal activation (Fos protein expression) to similarly trained rats that did not form this association (non-learners). Learners had greater food-seeking behavior and neuronal activation within the medial prefrontal cortex (mPFC), suggesting that mPFC subregions might encode initial food self-administration memories. To test the functional relevance of mPFC Fos-expressing ensembles to subsequent food seeking, we tested region-wide inactivation of the IL using muscimol+baclofen and neuronal ensemble-specific ablation using the Daun02 inactivation procedure. Both region-wide inactivation and ensemble-specific inactivation of the IL significantly decreased food seeking. These data suggest that IL neuronal ensembles form during initial learning of food self-administration behavior, and furthermore, that these ensembles play a functional role in food seeking.
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34
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Meyer HC, Gerhard DM, Amelio PA, Lee FS. Pre-adolescent stress disrupts adult, but not adolescent, safety learning. Behav Brain Res 2021; 400:113005. [PMID: 33171149 PMCID: PMC8283802 DOI: 10.1016/j.bbr.2020.113005] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/26/2020] [Accepted: 11/03/2020] [Indexed: 11/28/2022]
Abstract
Anxiety disorders are highly prevalent across the lifespan, although diagnoses peak early in adolescence. As a method for inhibiting fear, safety signals have the potential to augment conventional treatments for anxiety. However, the ability to acquire and use safety signals during adolescence remains unclear. Moreover, the impact of stress on safety learning has received surprisingly little attention given that stress is a major factor preceding anxiety onset. In this study, mice were trained in a discriminative conditioning protocol to facilitate safety learning and were tested for fear inhibition using a conditioned safety signal. Next, independent groups of mice were exposed to chronic unpredictable stress (CUS) conditions between postnatal day 22 and 28, followed by tests for anxiety-like phenotypes or fear inhibition using a safety signal, performed either 24 h or five weeks following CUS. Pre-adolescent CUS reduced weight in adolescence and this effect endured into adulthood. CUS also increased specific anxiety-like behaviors in adolescence that were unique from the increase in anxiety observed in adulthood. Despite increased anxiety-like behaviors, adolescents were able to learn about and effectively use safety signals to inhibit fear. In contrast, adults that experienced CUS showed a subtle increase in anxiety but had impaired safety signal learning and usage. Together, these findings indicate that pre-adolescent stress has immediate and enduring effects on anxiety-like behaviors but impairs the capacity for conditioned inhibition only following incubation.
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Affiliation(s)
- Heidi C Meyer
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA.
| | - Danielle M Gerhard
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA.
| | - Paia A Amelio
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA; School of Communication, Northwestern University, Evanston, IL, 60208, USA.
| | - Francis S Lee
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA; Sackler Institute for Developmental Psychobiology, Weill Cornell Medicine, New York, NY, 10065, USA.
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35
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Wandres M, Pfarr S, Molnár B, Schöllkopf U, Ercsey-Ravasz M, Sommer WH, Körber C. Alcohol and sweet reward are encoded by distinct meta-ensembles. Neuropharmacology 2021; 195:108496. [PMID: 33582149 DOI: 10.1016/j.neuropharm.2021.108496] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/30/2021] [Accepted: 02/08/2021] [Indexed: 01/14/2023]
Abstract
Cue-reward associations form distinct memories that can drive appetitive behaviors and cravings for both drugs and natural rewards. It is still unclear how such memories are encoded in the brain's reward system. We trained rats to concurrently self-administer either alcohol or a sweet saccharin solution as drug or natural rewards, respectively. Memory recall due to cue exposure reactivated reward-associated functional ensembles in reward-related brain regions, marked by a neural cFos response. While the local ensembles activated by cue presentation for either reward consisted of similar numbers of neurons, using advanced statistical network theory, we found robust reward-specific co-activation patterns across brain regions. Interestingly, the resulting meta-ensemble networks differed by the most influential regions, which in case of saccharin comprised the prefrontal cortex, while for alcohol seeking control shifted to insular cortex with strong involvement of the amygdala. Our results support the view of memory representation as a differential co-activation of local neuronal ensembles. This article is part of the special issue on 'Neurocircuitry Modulating Drug and Alcohol Abuse'.
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Affiliation(s)
- Miriam Wandres
- Institute of Anatomy and Cell Biology, Department of Functional Neuroanatomy, Heidelberg University, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Simone Pfarr
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany
| | - Botond Molnár
- Faculty of Mathematics and Informatics, Babeş-Bolyai University, Cluj-Napoca, Romania; Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, Romania; Transylvanian Institute of Neuroscience, Network Science Lab, Cluj-Napoca, Romania
| | - Ursula Schöllkopf
- Institute of Anatomy and Cell Biology, Department of Functional Neuroanatomy, Heidelberg University, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Maria Ercsey-Ravasz
- Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, Romania; Transylvanian Institute of Neuroscience, Network Science Lab, Cluj-Napoca, Romania
| | - Wolfgang H Sommer
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany; Department of Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany.
| | - Christoph Körber
- Institute of Anatomy and Cell Biology, Department of Functional Neuroanatomy, Heidelberg University, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany.
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Odriozola P, Gee DG. Learning About Safety: Conditioned Inhibition as a Novel Approach to Fear Reduction Targeting the Developing Brain. Am J Psychiatry 2021; 178:136-155. [PMID: 33167673 PMCID: PMC7951569 DOI: 10.1176/appi.ajp.2020.20020232] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Adolescence is a peak time for the onset of psychiatric disorders, with anxiety disorders being the most common and affecting as many as 30% of youths. A core feature of anxiety disorders is difficulty regulating fear, with evidence suggesting deficits in extinction learning and corresponding alterations in frontolimbic circuitry. Despite marked changes in this neural circuitry and extinction learning throughout development, interventions for anxious youths are largely based on principles of extinction learning studied in adulthood. Safety signal learning, based on conditioned inhibition of fear in the presence of a cue that indicates safety, has been shown to effectively reduce anxiety-like behavior in animal models and attenuate fear responses in healthy adults. Cross-species evidence suggests that safety signal learning involves connections between the ventral hippocampus and the prelimbic cortex in rodents or the dorsal anterior cingulate cortex in humans. Particularly because this pathway follows a different developmental trajectory than fronto-amygdala circuitry involved in traditional extinction learning, safety cues may provide a novel approach to reducing fear in youths. In this review, the authors leverage a translational framework to bring together findings from studies in animal models and humans and to bridge the gap between research on basic neuroscience and clinical treatment. The authors consider the potential application of safety signal learning for optimizing interventions for anxious youths by targeting the biological state of the developing brain. Based on the existing cross-species literature on safety signal learning, they propose that the judicious use of safety cues may be an effective and neurodevelopmentally optimized approach to enhancing treatment outcomes for youths with anxiety disorders.
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Affiliation(s)
| | - Dylan G. Gee
- Department of Psychology, Yale University, New Haven, Conn
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Absence Makes the Mind Grow Fonder: Reconceptualizing Studies of Safety Learning in Translational Research on Anxiety. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2021; 21:1-13. [PMID: 33420710 DOI: 10.3758/s13415-020-00855-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/19/2020] [Indexed: 01/04/2023]
Abstract
Overgeneralized fear (OGF), or indiscriminate fear responses to signals of threat and nonthreat, is a well-studied cognitive mechanism in human anxiety. Anxiety-related OGF has been studied primarily through fear-learning paradigms and conceptualized as overly exaggerated learning of cues signaling imminent threat. However, the role of safety learning in OGF has not only received much less empirical attention but has been fundamentally conceptualized as learning about the absence of threat rather than the presence of safety. As a result, the relative contributions of exaggerated fear learning and weakened safety learning to anxiety-related OGF remain poorly understood, as do the potentially unique biological and behavioral underpinnings of safety learning. The present review outlines these gaps by, first, summarizing animal and human research on safety learning related to anxiety and OGF. Second, we outline innovations in methods to tease apart unique biological and behavioral contributions of safety learning to OGF. Lastly, we describe clinical and treatment implications of this framework for translational research relevant to human anxiety.
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Saul’skaya NB, Marchuk OE, Puzanova MA, Trofimova NA. Activation of Serotonin System in the Medial Prefrontal Cortex by Sound Signals of Danger. NEUROCHEM J+ 2020. [DOI: 10.1134/s181971242004008x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Glover LR, McFadden KM, Bjorni M, Smith SR, Rovero NG, Oreizi-Esfahani S, Yoshida T, Postle AF, Nonaka M, Halladay LR, Holmes A. A prefrontal-bed nucleus of the stria terminalis circuit limits fear to uncertain threat. eLife 2020; 9:60812. [PMID: 33319747 PMCID: PMC7899651 DOI: 10.7554/elife.60812] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/11/2020] [Indexed: 12/30/2022] Open
Abstract
In many cases of trauma, the same environmental stimuli that become associated with aversive events are experienced on other occasions without adverse consequence. We examined neural circuits underlying partially reinforced fear (PRF), whereby mice received tone-shock pairings on half of conditioning trials. Tone-elicited freezing was lower after PRF conditioning than fully reinforced fear (FRF) conditioning, despite an equivalent number of tone-shock pairings. PRF preferentially activated medial prefrontal cortex (mPFC) and bed nucleus of the stria terminalis (BNST). Chemogenetic inhibition of BNST-projecting mPFC neurons increased PRF, not FRF, freezing. Multiplexing chemogenetics with in vivo neuronal recordings showed elevated infralimbic cortex (IL) neuronal activity during CS onset and freezing cessation; these neural correlates were abolished by chemogenetic mPFC→BNST inhibition. These data suggest that mPFC→BNST neurons limit fear to threats with a history of partial association with an aversive stimulus, with potential implications for understanding the neural basis of trauma-related disorders.
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Affiliation(s)
- Lucas R Glover
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, United States
| | - Kerry M McFadden
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, United States
| | - Max Bjorni
- Department of Psychology, Santa Clara University, Santa Clara, United States
| | - Sawyer R Smith
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, United States
| | - Natalie G Rovero
- Department of Psychology, Santa Clara University, Santa Clara, United States
| | - Sarvar Oreizi-Esfahani
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, United States
| | - Takayuki Yoshida
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, United States
| | - Abagail F Postle
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, United States
| | - Mio Nonaka
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, United States
| | - Lindsay R Halladay
- Department of Psychology, Santa Clara University, Santa Clara, United States
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, United States
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Krueger JN, Sangha S. On the basis of sex: Differences in safety discrimination vs. conditioned inhibition. Behav Brain Res 2020; 400:113024. [PMID: 33290755 DOI: 10.1016/j.bbr.2020.113024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/19/2020] [Accepted: 11/18/2020] [Indexed: 01/04/2023]
Abstract
Inaccurate discrimination between threat and safety cues is a common symptom of anxiety disorders such as Post-Traumatic Stress Disorder (PTSD). Although females experience higher rates of these disorders than males, the body of literature examining sex differences in safety learning is still growing. Learning to discriminate safety cues from threat cues requires downregulating fear to the safety cue while continuing to express fear to the threat cue. However, successful discrimination between safety and threat cues does not necessarily guarantee that the safety cue can effectively reduce fear to the threat cue when they are presented together. The conditioned inhibitory ability of a safety cue to reduce fear in the presence of both safety and threat is most likely dependent on the ability to discriminate between the two. There are relatively few studies exploring conditioned inhibition as a method of safety learning. Adding to this knowledge gap is the general lack of inclusion of female subjects within these studies. In this review, we provide a qualitative review of our current knowledge of sex differences in safety discrimination versus conditioned inhibition in both humans and rodents. Overall, the literature suggests that while females and males perform similarly in discrimination learning, females show deficits in conditioned inhibition compared to males. Furthermore, while estrogen appears to have a protective effect on safety learning in humans, increased estrogen in female rodents appears to be correlated with impaired safety learning performance.
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Affiliation(s)
- Jamie N Krueger
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA.
| | - Susan Sangha
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 47907, USA; Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA.
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Liu J, Likhtik E, Shereen AD, Dennis-Tiwary TA, Casaccia P. White Matter Plasticity in Anxiety: Disruption of Neural Network Synchronization During Threat-Safety Discrimination. Front Cell Neurosci 2020; 14:587053. [PMID: 33250713 PMCID: PMC7674975 DOI: 10.3389/fncel.2020.587053] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/02/2020] [Indexed: 12/11/2022] Open
Abstract
Recent evidence highlighted the importance of white matter tracts in typical and atypical behaviors. White matter dynamically changes in response to learning, stress, and social experiences. Several lines of evidence have reported white matter dysfunction in psychiatric conditions, including depression, stress- and anxiety-related disorders. The mechanistic underpinnings of these associations, however, remain poorly understood. Here, we outline an integrative perspective positing a link between aberrant myelin plasticity and anxiety. Drawing on extant literature and emerging new findings, we suggest that in anxiety, unique changes may occur in response to threat and to safety learning and the ability to discriminate between both types of stimuli. We propose that altered myelin plasticity in the neural circuits underlying these two forms of learning relates to the emergence of anxiety-related disorders, by compromising mechanisms of neural network synchronization. The clinical and translational implications of this model for anxiety-related disorders are discussed.
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Affiliation(s)
- Jia Liu
- Advanced Science Research Center at the Graduate Center, Neuroscience Initiative, City University of New York, New York, NY, United States
| | - Ekaterina Likhtik
- Department of Biology, Hunter College, City University of New York, New York, NY, United States
- Graduate Program in Biology at the Graduate Center, City University of New York, New York, NY, United States
| | - A. Duke Shereen
- Advanced Science Research Center at the Graduate Center, Neuroscience Initiative, City University of New York, New York, NY, United States
| | - Tracy A. Dennis-Tiwary
- Department of Psychology, Hunter College, City University of New York, New York, NY, United States
- Graduate Program in Psychology and Behavioral and Cognitive Neuroscience at the Graduate Center, City University of New York, New York, NY, United States
| | - Patrizia Casaccia
- Advanced Science Research Center at the Graduate Center, Neuroscience Initiative, City University of New York, New York, NY, United States
- Graduate Program in Biology at the Graduate Center, City University of New York, New York, NY, United States
- Graduate Program in Biochemistry at the Graduate Center, City University of New York, New York, NY, United States
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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Infralimbic cortex controls fear memory generalization and susceptibility to extinction during consolidation. Sci Rep 2020; 10:15827. [PMID: 32985565 PMCID: PMC7522076 DOI: 10.1038/s41598-020-72856-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 09/03/2020] [Indexed: 01/22/2023] Open
Abstract
Lesioning or inactivating the infralimbic (IL) subregion of the medial prefrontal cortex before acquisition produces more generalized and extinction-resistant fear memories. However, whether and how it modulates memory specificity and extinction susceptibility while consolidation takes place is still unknown. The present study aims to investigate these questions using muscimol-induced temporary inactivation and anisomycin-induced protein synthesis inhibition in the rat IL following contextual fear conditioning. Results indicate that the IL activity immediately after acquisition, but not six hours later, controls memory generalization over a week, regardless of its strength. Such IL function depends on the context-shock pairing since muscimol induced no changes in animals exposed to immediate shocks or the conditioning context only. Animals in which the IL was inactivated during consolidation extinguished similarly to controls within the session but were unable to recall the extinction memory the following day. Noteworthy, these post-acquisition IL inactivation-induced effects were not associated with changes in anxiety, as assessed in the elevated plus-maze test. Anisomycin results indicate that the IL protein synthesis during consolidation contributes more to producing extinction-sensitive fear memories than memory specificity. Collectively, present results provide evidence for the IL's role in controlling generalization and susceptibility to extinction during fear memory consolidation.
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Nahmoud I, Vasquez JG, Cho H, Dennis-Tiwary T, Likhtik E. Salient safety conditioning improves novel discrimination learning. Behav Brain Res 2020; 397:112907. [PMID: 32956774 DOI: 10.1016/j.bbr.2020.112907] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/14/2020] [Accepted: 09/08/2020] [Indexed: 12/19/2022]
Abstract
Generalized fear is one purported mechanism of anxiety that is a target of clinical and basic research. Impaired fear discrimination has been primarily examined from the perspective of increased fear learning, rather than how learning about non-threatening stimuli affects fear discrimination. To address this question, we tested how three Safety Conditioning protocols with varied levels of salience allocated to the safety cue compared to classic Fear Conditioning in their impact on subsequent innate anxiety, and differential fear learning of new aversive and neutral cues. Using a high anxiety strain of mice (129SvEv, Taconic), we show that Fear Conditioned animals show little exploration of the anxiogenic center of an open field 24 h later, and poor discrimination during new differential conditioning 7 days later. Three groups of mice underwent Safety Conditioning, (i) the safety tone was unpaired with a shock, (ii) the safety tone was unpaired with the shock and co-terminated with a house light signaling the end of the safety period, and (iii) the safety tone was unpaired with the shock and its beginning co-occurred with a house light, signaling the start of a safety period. Mice from all Safety Conditioning groups showed higher levels of open field exploration than the Fear Conditioned mice 24 h after training. Furthermore, Safety Conditioned animals showed improved discrimination learning of a novel non-threat, with the Salient Beginning safety conditioned group performing best. These findings indicate that high anxiety animals benefit from salient safety training to improve exploration and discrimination of new non-threating stimuli.
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Affiliation(s)
- I Nahmoud
- Chemistry Dept., Hunter College, CUNY, New York, NY, United States
| | - J Ganay Vasquez
- Chemistry Dept., Hunter College, CUNY, New York, NY, United States
| | - H Cho
- Department of Psychology, The Graduate Center, CUNY, NY, United States; Psychology Dept., Hunter College, CUNY, New York, NY, United States
| | - T Dennis-Tiwary
- Department of Psychology, The Graduate Center, CUNY, NY, United States; Psychology Dept., Hunter College, CUNY, New York, NY, United States
| | - E Likhtik
- Biology Dept., Hunter College, CUNY, New York, NY, United States; Program in Biology, The Graduate Center, CUNY, NY, United States.
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Piantadosi PT, Yeates DCM, Floresco SB. Prefrontal cortical and nucleus accumbens contributions to discriminative conditioned suppression of reward-seeking. ACTA ACUST UNITED AC 2020; 27:429-440. [PMID: 32934096 PMCID: PMC7497111 DOI: 10.1101/lm.051912.120] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/02/2020] [Indexed: 12/18/2022]
Abstract
Fear can potently inhibit ongoing behavior, including reward-seeking, yet the neural circuits that underlie such suppression remain to be clarified. Prior studies have demonstrated that distinct subregions of the rodent medial prefrontal cortex (mPFC) differentially affect fear behavior, whereby fear expression is promoted by the more dorsal prelimbic cortex (PL) and inhibited by the more ventral infralimbic cortex (IL). These mPFC regions project to subregions of the nucleus accumbens, the core (NAcC) and shell (NAcS), that differentially contribute to reward-seeking as well as affective processes that may be relevant to fear expression. Here, we investigated how these mPFC and NAc subregions contribute to discriminative fear conditioning, assessed by conditioned suppression of reward-seeking. Bilateral inactivation of the NAcS or PL reduced the expression of conditioned suppression to a shock-associated CS+, whereas NAcC inactivation reduced reward-seeking without affecting suppression. IL inactivation caused a general reduction in conditioned suppression following discriminative conditioning, but not when using a single-stimulus design. Pharmacological disconnection of the PL → NAcS pathway revealed that this projection mediates conditioned suppression. These data add to a growing literature implicating discrete cortico-striatal pathways in the suppression of reward-seeking in response to aversive stimuli. Dysfunction within related structures may contribute to aberrant patterns of behavior in psychiatric illnesses including substance use disorders.
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Affiliation(s)
- Patrick T Piantadosi
- Department of Psychology and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Dylan C M Yeates
- Department of Psychology and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Stan B Floresco
- Department of Psychology and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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Individual expression of conditioned safety but not of conditioned relief is correlated with contextual fear. Behav Brain Res 2020; 393:112799. [DOI: 10.1016/j.bbr.2020.112799] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/19/2020] [Accepted: 07/05/2020] [Indexed: 11/20/2022]
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Neural correlates of safety learning. Behav Brain Res 2020; 396:112884. [PMID: 32871228 DOI: 10.1016/j.bbr.2020.112884] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/24/2020] [Accepted: 08/21/2020] [Indexed: 02/01/2023]
Abstract
Accurate discrimination between safe and dangerous stimuli is essential for survival. Prior research has begun to uncover the neural structures that are necessary for learning this discrimination, but exploration of brain regions involved in this learning process has been mostly limited to males. Recent findings show sex differences in discrimination learning, with reduced fear expression to safe cues in females compared to males. Here, we used male and female Sprague Dawley rats to explore neural activation, as measured by Fos expression, in fear and safety learning related brain regions. Neural activation after fear discrimination (Discrimination) was compared between males and females, as well as with fear conditioned (Fear Only) and stimulus presented (Control) conditions. Correlations of discrimination ability and neural activation were also calculated. We uncovered a correlation between central amygdala (CeA) activation and discrimination abilities in males and females. Anterior medial bed nucleus of the stria terminalis (BNST) was the only region where sex differences in Fos counts were observed in the Discrimination condition, and the only region where neural activation significantly differed between Fear Only and Discrimination conditions. Together, these findings indicate the importance of fear expression circuitry in mediating discrimination responses and generate important questions for future investigation.
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Prelimbic and Infralimbic Prefrontal Regulation of Active and Inhibitory Avoidance and Reward-Seeking. J Neurosci 2020; 40:4773-4787. [PMID: 32393535 DOI: 10.1523/jneurosci.0414-20.2020] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/23/2020] [Accepted: 05/03/2020] [Indexed: 11/21/2022] Open
Abstract
Flexible initiation or suppression of actions to avoid aversive events is crucial for survival. The prelimbic (PL) and infralimbic (IL) regions of the medial prefrontal cortex (mPFC) have been implicated in different aspects of avoidance and reward-seeking, but their respective contribution in instigating versus suppressing actions in aversive contexts remains to be clarified. We examined mPFC involvement in different forms of avoidance in rats well trained on different cued lever-press avoidance tasks. Active/inhibitory avoidance required flexible discrimination between auditory cues signaling foot-shock could be avoided by making or withholding instrumental responses. On a simpler active avoidance task, a single cue signaled when a lever press would avoid shock. PL inactivation disrupted active but not inhibitory avoidance on the discriminative task while having no effect on single-cued avoidance. In comparison, IL inactivation broadly impaired active and inhibitory avoidance. Conversely, on a cued appetitive go/no-go task, both IL and PL inactivation impaired inhibitory but not active reward-seeking, the latter effect being diametrically opposite to that observed on the avoidance task. These findings highlight the complex manner in which different mPFC regions aid in initiating or inhibiting actions in the service of avoiding aversive outcomes or obtaining rewarding ones. IL facilitates active avoidance but suppress inappropriate actions in appetitive and aversive contexts. In contrast, contextual valence plays a critical role in how the PL is recruited in initiating or suppressing actions, which may relate to the degree of cognitive control required to flexibly negotiate response or motivational conflicts and override prepotent behaviors.SIGNIFICANCE STATEMENT Choosing to make or withhold actions in a context-appropriate manner to avoid aversive events or obtain other goals is a critical survival skill. Different medial prefrontal cortex (mPFC) regions have been implicated in certain aspects of avoidance, but their contributions to instigating or suppressing actions remains to be clarified. Here, we show that the dorsal, prelimbic (PL) region of the medial PFC aids active avoidance in situations requiring flexible mitigation of response conflicts, but also aids in withholding responses to obtain rewards. In comparison the ventral infralimbic (IL) cortex plays a broader role in active and inhibitory avoidance as well as suppressing actions to obtain rewards. These findings provide insight into mechanisms underlying normal and maladaptive avoidance behaviors and response inhibition.
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Gutzeit VA, Ahuna K, Santos TL, Cunningham AM, Sadsad Rooney M, Muñoz Zamora A, Denny CA, Donaldson ZR. Optogenetic reactivation of prefrontal social neural ensembles mimics social buffering of fear. Neuropsychopharmacology 2020; 45:1068-1077. [PMID: 32035426 PMCID: PMC7162965 DOI: 10.1038/s41386-020-0631-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 01/23/2020] [Accepted: 01/28/2020] [Indexed: 12/12/2022]
Abstract
Social buffering occurs when the presence of a companion attenuates the physiological and/or behavioral effects of a stressful or fear-provoking event. It represents a way in which social interactions can immediately and potently modulate behavior. As such, social buffering is one mechanism by which strong social support increases resilience to mental illness. Although the behavioral and neuroendocrine impacts of social buffering are well studied in multiple species, including humans, the neuronal underpinnings of this behavioral phenomenon remain largely unexplored. Previous work has shown that the infralimbic prefrontal cortex (IL-PFC) is important for processing social information and, in separate studies, for modulating fear and anxiety. Thus, we hypothesized that socially active cells within the IL-PFC may integrate social information to modulate fear responsivity. To test this hypothesis, we employed social buffering paradigms in male and female mice. Similar to prior studies in rats, we found that the presence of a cagemate reduced freezing in fear- and anxiety-provoking contexts. In accordance with previous work, we demonstrated that interaction with a novel or familiar conspecific induces activity in the IL-PFC as evidenced by increased immediate early gene (IEG) expression. We then utilized an activity-dependent tagging murine line, the ArcCreERT2 mice, to express channelrhodopsin (ChR2) in neurons active during the social encoding of a new cagemate. We found that optogenetic reactivation of these socially active neuronal ensembles phenocopied the effects of cagemate presence in male and female mice in learned and innate fear contexts without being inherently rewarding or altering locomotion. These data suggest that a social neural ensemble within the IL-PFC may contribute to social buffering of fear. These neurons may represent a novel therapeutic target for fear and anxiety disorders.
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Affiliation(s)
- Vanessa A. Gutzeit
- 000000041936877Xgrid.5386.8Neuroscience Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065 USA
| | - Kylia Ahuna
- 0000000096214564grid.266190.aDepartment of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Tabia L. Santos
- Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY 11549 USA
| | - Ashley M. Cunningham
- 0000 0001 0670 2351grid.59734.3cMt. Sinai School of Medicine, New York, NY 10029 USA
| | | | - Andrea Muñoz Zamora
- 0000000419368729grid.21729.3fDepartment of Psychiatry, Columbia University Irving Medical Center (CUIMC), New York, NY 10032 USA ,0000 0000 8499 1112grid.413734.6Division of Systems Neuroscience, New York State Psychiatric Institute (NYSPI)/Research Foundation for Mental Hygiene, Inc. (RFMH), New York, NY 10032 USA
| | - Christine A. Denny
- 0000000419368729grid.21729.3fDepartment of Psychiatry, Columbia University Irving Medical Center (CUIMC), New York, NY 10032 USA ,0000 0000 8499 1112grid.413734.6Division of Systems Neuroscience, New York State Psychiatric Institute (NYSPI)/Research Foundation for Mental Hygiene, Inc. (RFMH), New York, NY 10032 USA
| | - Zoe R. Donaldson
- 0000000096214564grid.266190.aDepartment of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO 80309 USA ,0000000096214564grid.266190.aDepartment of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309 USA
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Kreutzmann JC, Fendt M. Chronic inhibition of GABA synthesis in the infralimbic cortex facilitates conditioned safety memory and reduces contextual fear. Transl Psychiatry 2020; 10:120. [PMID: 32332716 PMCID: PMC7182568 DOI: 10.1038/s41398-020-0788-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/12/2020] [Accepted: 03/25/2020] [Indexed: 12/20/2022] Open
Abstract
Accurate discrimination between danger and safety cues is essential for survival. Recent findings in humans indicate that patients suffering from anxiety disorders cannot reliably use safety cues in order to inhibit fear responses. However, the neuroanatomical pathways of conditioned safety are still unclear. Aim of the present study was to investigate whether chronic inhibition of GABA synthesis in the infralimbic (IL) cortex, a critical region for fear inhibition, would lead to enhanced conditioned safety memory. Male Sprague Dawley rats were equipped with osmotic mini-pumps attached to an infusion cannula aimed at the IL. Mini-pumps were either filled with the glutamate decarboxylase (GAD) inhibitor L-allylglycine (L-AG) or the inactive enantiomer D-allylglycine (D-AG). Previous studies demonstrated that chronic infusions of L-AG lead to lower GABA levels and overall enhanced neural activity. The effect of IL disinhibition on conditioned safety was investigated utilizing the acoustic startle response. Chronic disinhibition of the IL facilitated conditioned safety memory, along with reduced contextual fear and lower corticosterone levels. The present findings suggest that the IL is a key brain region for conditioned safety memory. Because anxiety disorder patients are often not capable to use safety cues to inhibit unnecessary fear responses, the present findings are of clinical relevance and could potentially contribute to therapy optimization.
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Affiliation(s)
- Judith C. Kreutzmann
- grid.5807.a0000 0001 1018 4307Institute for Pharmacology & Toxicology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany ,grid.418723.b0000 0001 2109 6265Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Markus Fendt
- grid.5807.a0000 0001 1018 4307Institute for Pharmacology & Toxicology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany ,grid.5807.a0000 0001 1018 4307Center of Behavioral Brain Sciences, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
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Sex differences in auditory fear discrimination are associated with altered medial prefrontal cortex function. Sci Rep 2020; 10:6300. [PMID: 32286467 PMCID: PMC7156682 DOI: 10.1038/s41598-020-63405-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/28/2020] [Indexed: 01/05/2023] Open
Abstract
The increased prevalence of post-traumatic stress disorder (PTSD) that is observed in women may involve sex differences in learned fear inhibition and medial prefrontal cortex (mPFC) function. PTSD is characterized by fear overgeneralization involving impaired fear regulation by safety signals. We recently found that males show fear discrimination and females show fear generalization involving reduced safety signalling after extended fear discrimination training. Here we determined if these sex differences involve altered mPFC function. Male and female rats underwent three days of auditory fear discrimination training, where one tone (CS+) was paired with footshock and another tone (CS−) was presented alone. Local field potentials were recorded from prelimbic (PL) and infralimbic (IL) mPFC during retrieval. We found that males discriminated and females generalized based on cue-induced freezing at retrieval. This was accompanied by sex differences in basal theta and gamma oscillations in PL and IL. Importantly, males also showed PL/IL theta activation during safety signalling by the CS− and IL gamma activation in response to the threat-related CS+, both of which were absent in females. These results add to growing evidence indicating that sex differences in learned fear inhibition are associated with altered mPFC function.
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