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Iqbal J, Huang GD, Xue YX, Yang M, Jia XJ. Role of estrogen in sex differences in memory, emotion and neuropsychiatric disorders. Mol Biol Rep 2024; 51:415. [PMID: 38472517 DOI: 10.1007/s11033-024-09374-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 02/22/2024] [Indexed: 03/14/2024]
Abstract
Estrogen regulates a wide range of neuronal functions in the brain, such as dendritic spine formation, remodeling of synaptic plasticity, cognition, neurotransmission, and neurodevelopment. Estrogen interacts with intracellular estrogen receptors (ERs) and membrane-bound ERs to produce its effect via genomic and non-genomic pathways. Any alterations in these pathways affect the number, size, and shape of dendritic spines in neurons associated with psychiatric diseases. Increasing evidence suggests that estrogen fluctuation causes changes in dendritic spine density, morphology, and synapse numbers of excitatory and inhibitory neurons differently in males and females. In this review, we discuss the role of estrogen hormone in rodents and humans based on sex differences. First, we explain estrogen role in learning and memory and show that a high estrogen level alleviates the deficits in learning and memory. Secondly, we point out that estrogen produces a striking difference in emotional memories in men and women, which leads them to display sex-specific differences in underlying neuronal signaling. Lastly, we discuss that fluctuations in estrogen levels in men and women are related to neuropsychiatric disorders, including schizophrenia, autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), bipolar disorder (BPD), major depressive disorder (MDD), substance use disorder (SUD), and anxiety disorders.
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Affiliation(s)
- Javed Iqbal
- Department of Addiction Medicine, Shenzhen Clinical Research Center for Mental Disorders, Shenzhen Kangning Hospital & Shenzhen Mental Health Center, No. 77 Zhenbi Road, Pingshan District, Shenzhen, 518118, Guangdong, China
| | - Geng-Di Huang
- Department of Addiction Medicine, Shenzhen Clinical Research Center for Mental Disorders, Shenzhen Kangning Hospital & Shenzhen Mental Health Center, No. 77 Zhenbi Road, Pingshan District, Shenzhen, 518118, Guangdong, China
| | - Yan-Xue Xue
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China
| | - Mei Yang
- Department of Addiction Medicine, Shenzhen Clinical Research Center for Mental Disorders, Shenzhen Kangning Hospital & Shenzhen Mental Health Center, No. 77 Zhenbi Road, Pingshan District, Shenzhen, 518118, Guangdong, China.
- Clinical College of Mental Health, Shenzhen University Health Science Center, Shenzhen, China.
- Affiliated Mental Health Center, Southern University of Science and Technology, Shenzhen, China.
| | - Xiao-Jian Jia
- Department of Addiction Medicine, Shenzhen Clinical Research Center for Mental Disorders, Shenzhen Kangning Hospital & Shenzhen Mental Health Center, No. 77 Zhenbi Road, Pingshan District, Shenzhen, 518118, Guangdong, China.
- Clinical College of Mental Health, Shenzhen University Health Science Center, Shenzhen, China.
- Affiliated Mental Health Center, Southern University of Science and Technology, Shenzhen, China.
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Shimoda R, Amaya Y, Okamoto M, Soya S, Soya M, Koizumi H, Nakamura K, Hiraga T, Torma F, Soya H. Accelerated Fear Extinction by Regular Light-Intensity Exercise: A Possible Role of Hippocampal BDNF-TrkB Signaling. Med Sci Sports Exerc 2024; 56:221-229. [PMID: 38214538 DOI: 10.1249/mss.0000000000003312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
PURPOSE Growing concern exists worldwide about stress-related mental disorders, such as posttraumatic stress disorder (PTSD), often linked to hippocampal dysfunctions. Recognizing this connection, regular light-intensity exercise (LIE)-such as yoga, walking, or slow jogging-may offer a solution. Easily accessible even to vulnerable individuals, LIE has been found to enhance hippocampus-based cognitive functions through the stimulation of neurotrophic factors like brain-derived neurotrophic factor (BDNF). A prior study that demonstrated BDNF's role in extinguishing original fear memory further leads us to propose that a consistent LIE training might drive fear extinction learning, offering potential therapeutic benefits through BDNF signaling. METHODS Eleven-week-old Wistar rats underwent 4 wk of training under conditions of sedentary, LIE, or moderate-intensity exercise (MOE) after contextual or auditory fear conditioning. Subsequently, fear extinction tests were performed. We then administered intraperitoneal (i.p.) ANA-12, a selective antagonist of tropomyosin receptor kinase B (TrkB), or a vehicle to explore the role of BDNF signaling in exercise-induced fear extinction among the LIE rats. Following the regular exercise training, further fear extinction tests were conducted, and hippocampal protein analysis was performed using Western blotting. RESULTS Both LIE and MOE over 4 wk accelerated hippocampus-associated contextual fear extinction compared with sedentary. In addition, 4 wk of LIE with i.p. administered vehicle increased hippocampal BDNF and TrkB protein levels. In contrast, i.p. ANA-12 administration fully blocked the LIE-enhanced protein levels and its effect on contextual fear extinction. CONCLUSIONS Our findings reveal that LIE regimen promotes fear extinction learning, at least partially tied to hippocampal BDNF-TrkB signaling. This suggests that even regular light exercise could alleviate the excessive fear response in anxiety disorders and PTSD, providing hope for those affected.
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Affiliation(s)
- Ryo Shimoda
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, JAPAN
| | - Yuki Amaya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, JAPAN
| | | | - Shingo Soya
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, JAPAN
| | - Mariko Soya
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, JAPAN
| | - Hikaru Koizumi
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, JAPAN
| | - Kengo Nakamura
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, JAPAN
| | - Taichi Hiraga
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, JAPAN
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Jones MJ, Uzuneser TC, Clement T, Wang H, Ojima I, Rushlow WJ, Laviolette SR. Inhibition of fatty acid binding protein-5 in the basolateral amygdala induces anxiolytic effects and accelerates fear memory extinction. Psychopharmacology (Berl) 2024; 241:119-138. [PMID: 37747506 DOI: 10.1007/s00213-023-06468-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/11/2023] [Indexed: 09/26/2023]
Abstract
RATIONALE The endocannabinoid (eCB) system critically controls anxiety and fear-related behaviours. Anandamide (AEA), a prominent eCB ligand, is a hydrophobic lipid that requires chaperone proteins such as Fatty Acid Binding Proteins (FABPs) for intracellular transport. Intracellular AEA transport is necessary for degradation, so blocking FABP activity increases AEA neurotransmission. OBJECTIVE To investigate the effects of a novel FABP5 inhibitor (SBFI-103) in the basolateral amygdala (BLA) on anxiety and fear memory. METHODS We infused SBFI-103 (0.5 μg-5 μg) to the BLA of adult male Sprague Dawley rats and ran various anxiety and fear memory behavioural assays, neurophysiological recordings, and localized molecular signaling analyses. We also co-infused SBFI-103 with the AEA inhibitor, LEI-401 (3 μg and 10 μg) to investigate the potential role of AEA in these phenomena. RESULTS Acute intra-BLA administration of SBFI-103 produced strong anxiolytic effects across multiple behavioural tests. Furthermore, animals exhibited acute and long-term accelerated associative fear memory extinction following intra-BLA FABP5 inhibition. In addition, BLA FABP5 inhibition induced strong modulatory effects on putative PFC pyramidal neurons along with significantly increased gamma oscillation power. Finally, we observed local BLA changes in the phosphorylation activity of various anxiety- and fear memory-related molecular biomarkers in the PI3K/Akt and MAPK/Erk signaling pathways. At all three levels of analyses, we found the functional effects of SBFI-103 depend on availability of the AEA ligand. CONCLUSIONS These findings demonstrate a novel intra-BLA FABP5 signaling mechanism regulating anxiety and fear memory behaviours, neuronal activity states, local anxiety-related molecular pathways, and functional AEA modulation.
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Affiliation(s)
- Matthew J Jones
- Department of Neuroscience, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond St, London, ON, Canada
| | - Taygun C Uzuneser
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond St, London, ON, Canada
| | - Timothy Clement
- Institute of Chemical Biology and Drug Discoveries, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, USA
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, USA
| | - Hehe Wang
- Institute of Chemical Biology and Drug Discoveries, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, USA
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, USA
| | - Iwao Ojima
- Institute of Chemical Biology and Drug Discoveries, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, USA
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, USA
| | - Walter J Rushlow
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond St, London, ON, Canada
- Department of Psychiatry, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond St, London, ON, Canada
| | - Steven R Laviolette
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond St, London, ON, Canada.
- Department of Psychiatry, Schulich School of Medicine and Dentistry, University of Western Ontario, 1151 Richmond St, London, ON, Canada.
- Lawson Health Research Institute, 268 Grosvenor St, London, ON, Canada.
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Palamarchuk IS, Slavich GM, Vaillancourt T, Rajji TK. Stress-related cellular pathophysiology as a crosstalk risk factor for neurocognitive and psychiatric disorders. BMC Neurosci 2023; 24:65. [PMID: 38087196 PMCID: PMC10714507 DOI: 10.1186/s12868-023-00831-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 10/24/2023] [Indexed: 12/18/2023] Open
Abstract
In this narrative review, we examine biological processes linking psychological stress and cognition, with a focus on how psychological stress can activate multiple neurobiological mechanisms that drive cognitive decline and behavioral change. First, we describe the general neurobiology of the stress response to define neurocognitive stress reactivity. Second, we review aspects of epigenetic regulation, synaptic transmission, sex hormones, photoperiodic plasticity, and psychoneuroimmunological processes that can contribute to cognitive decline and neuropsychiatric conditions. Third, we explain mechanistic processes linking the stress response and neuropathology. Fourth, we discuss molecular nuances such as an interplay between kinases and proteins, as well as differential role of sex hormones, that can increase vulnerability to cognitive and emotional dysregulation following stress. Finally, we explicate several testable hypotheses for stress, neurocognitive, and neuropsychiatric research. Together, this work highlights how stress processes alter neurophysiology on multiple levels to increase individuals' risk for neurocognitive and psychiatric disorders, and points toward novel therapeutic targets for mitigating these effects. The resulting models can thus advance dementia and mental health research, and translational neuroscience, with an eye toward clinical application in cognitive and behavioral neurology, and psychiatry.
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Affiliation(s)
- Iryna S Palamarchuk
- Centre for Addiction and Mental Health, 1001 Queen Street West, Toronto, ON, M6J1H4, Canada.
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
- Sunnybrook Health Sciences Centre, Division of Neurology, Toronto, ON, Canada.
- Temerty Faculty of Medicine, Toronto Dementia Research Alliance, University of Toronto, Toronto, ON, Canada.
| | - George M Slavich
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, USA
| | - Tracy Vaillancourt
- Counselling Psychology, Faculty of Education, University of Ottawa, Ottawa, ON, Canada
- School of Psychology, Faculty of Social Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Tarek K Rajji
- Centre for Addiction and Mental Health, 1001 Queen Street West, Toronto, ON, M6J1H4, Canada
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Temerty Faculty of Medicine, Toronto Dementia Research Alliance, University of Toronto, Toronto, ON, Canada
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Allgire E, Ahlbrand RA, Nawreen N, Ajmani A, Hoover C, McAlees JW, Lewkowich IP, Sah R. Altered Fear Behavior in Aeroallergen House Dust Mite Exposed C57Bl/6 Mice: A Model of Th2-skewed Airway Inflammation. Neuroscience 2023; 528:75-88. [PMID: 37516435 PMCID: PMC10530159 DOI: 10.1016/j.neuroscience.2023.07.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/05/2023] [Accepted: 07/19/2023] [Indexed: 07/31/2023]
Abstract
There is a growing interest for studying the impact of chronic inflammation, particularly lung inflammation, on the brain and behavior. This includes asthma, a chronic inflammatory condition, that has been associated with psychiatric conditions such as posttraumatic stress disorder (PTSD). Although asthma is driven by elevated production of Th2 cytokines (IL-4, IL-5 and IL-13), which drive asthma symptomology, recent work demonstrates that concomitant Th1 or Th17 cytokine production can worsen asthma severity. We previously demonstrated a detrimental link between PTSD-relevant fear behavior and allergen-induced lung inflammation associated with a mixed Th2/Th17-inflammatory profile in mice. However, the behavioral effects of Th2-skewed airway inflammation, typical to mild/moderate asthma, are unknown. Therefore, we investigated fear conditioning/extinction in allergen house dust mite (HDM)-exposed C57Bl/6 mice, a model of Th2-skewed allergic asthma. Behaviors relevant to panic, anxiety, and depression were also assessed. Furthermore, we investigated the accumulation of Th2/Th17-cytokine-expressing cells in lung and brain, and the neuronal activation marker, ΔFosB, in fear regulatory brain areas. HDM-exposed mice elicited lower freezing during fear extinction with no effects on acquisition and conditioned fear. No HDM effect on panic, anxiety or depression-relevant behaviors was observed. While HDM evoked a Th2-skewed immune response in lung tissue, no significant alterations in brain Th cell subsets were observed. Significantly reduced ΔFosB+ cells in the basolateral amygdala of HDM mice were observed post extinction. Our data indicate that allergen-driven Th2-skewed responses may induce fear extinction promoting effects, highlighting beneficial interactions of Th2-associated immune mediators with fear regulatory circuits.
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Affiliation(s)
- E Allgire
- Dept. of Pharmacology & Systems Physiology, University of Cincinnati, Cincinnati, OH 45220, United States; Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45220, United States
| | - R A Ahlbrand
- Dept. of Pharmacology & Systems Physiology, University of Cincinnati, Cincinnati, OH 45220, United States
| | - N Nawreen
- Dept. of Pharmacology & Systems Physiology, University of Cincinnati, Cincinnati, OH 45220, United States; Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45220, United States
| | - A Ajmani
- Neuroscience Undergraduate Program, University of Cincinnati, Cincinnati, OH 45220, United States
| | - C Hoover
- Neuroscience Undergraduate Program, University of Cincinnati, Cincinnati, OH 45220, United States
| | - J W McAlees
- Division of Immunobiology, Children's Hospital Medical Center, Cincinnati, OH 45220, United States
| | - I P Lewkowich
- Division of Immunobiology, Children's Hospital Medical Center, Cincinnati, OH 45220, United States; Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45220, United States
| | - R Sah
- Dept. of Pharmacology & Systems Physiology, University of Cincinnati, Cincinnati, OH 45220, United States; Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45220, United States; VA Medical Center, Cincinnati, OH 45220, United States.
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6
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Khalil V, Faress I, Mermet-Joret N, Kerwin P, Yonehara K, Nabavi S. Subcortico-amygdala pathway processes innate and learned threats. eLife 2023; 12:e85459. [PMID: 37526552 PMCID: PMC10449383 DOI: 10.7554/elife.85459] [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: 12/08/2022] [Accepted: 07/18/2023] [Indexed: 08/02/2023] Open
Abstract
Behavioral flexibility and timely reactions to salient stimuli are essential for survival. The subcortical thalamic-basolateral amygdala (BLA) pathway serves as a shortcut for salient stimuli ensuring rapid processing. Here, we show that BLA neuronal and thalamic axonal activity in mice mirror the defensive behavior evoked by an innate visual threat as well as an auditory learned threat. Importantly, perturbing this pathway compromises defensive responses to both forms of threats, in that animals fail to switch from exploratory to defensive behavior. Despite the shared pathway between the two forms of threat processing, we observed noticeable differences. Blocking β-adrenergic receptors impairs the defensive response to the innate but not the learned threats. This reduced defensive response, surprisingly, is reflected in the suppression of the activity exclusively in the BLA as the thalamic input response remains intact. Our side-by-side examination highlights the similarities and differences between innate and learned threat-processing, thus providing new fundamental insights.
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Affiliation(s)
- Valentina Khalil
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
- Center for Proteins in Memory – PROMEMO, Danish National Research Foundation, Aarhus UniversityAarhusDenmark
| | - Islam Faress
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
- Center for Proteins in Memory – PROMEMO, Danish National Research Foundation, Aarhus UniversityAarhusDenmark
- Department of Biomedicine, Aarhus UniversityAarhusDenmark
| | - Noëmie Mermet-Joret
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
- Center for Proteins in Memory – PROMEMO, Danish National Research Foundation, Aarhus UniversityAarhusDenmark
| | - Peter Kerwin
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
| | - Keisuke Yonehara
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- Department of Biomedicine, Aarhus UniversityAarhusDenmark
- Multiscale Sensory Structure Laboratory, National Institute of GeneticsMishimaJapan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI)MishimaJapan
| | - Sadegh Nabavi
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
- Center for Proteins in Memory – PROMEMO, Danish National Research Foundation, Aarhus UniversityAarhusDenmark
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Meamar M, Rashidy-Pour A, Rahmani M, Vafaei AA, Raise-Abdullahi P. Glucocorticoid- β-adrenoceptors interactions in the infralimbic cortex in acquisition and consolidation of auditory fear memory extinction in rats. Pharmacol Biochem Behav 2023; 225:173560. [PMID: 37094708 DOI: 10.1016/j.pbb.2023.173560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/17/2023] [Accepted: 04/19/2023] [Indexed: 04/26/2023]
Abstract
This study investigated the interactive effect of glucocorticoid and β-adrenoceptors in the infralimbic (IL) cortex on the acquisition and consolidation of fear extinction in rats' auditory fear conditioning (AFC) task. On day 1, rats underwent habituation for 9 min (12 tonnes, 10 s, 4 kHz, 80 dB, without footshock). On day 2 (conditioning), rats received 3 mild electrical footshocks (US; 2 s, 0.5 mA) paired with the auditory-conditioned stimulus (CS; tone: 30 s, 4 kHz, 80 dB). On days 3-5 (Ext 1-3), rats received 15 tonnes with no footshock in the test box. Intra-IL injection of corticosterone (CORT, 20 ng/0.5 μl per side) before Ext 1 and after Ext 1-2, respectively, facilitated the acquisition and consolidation of fear memory extinction. Intra-IL injection of the β2-adrenoceptor agonist clenbuterol (CLEN, 50 ng/0.5 μl per side) inhibited, but the β-adrenoceptor antagonist propranolol (PROP, 500 ng/0.5 μl per side) enhanced the facilitatory effects of CORT on fear memory extinction. CORT injection before the acquisition of fear extinction increased p-ERK levels in the IL. Co-injection of CORT with CLEN increased, but PROP decreased p-ERK activities. CORT injection after the consolidation of fear extinction increased p-CREB in the IL. Co-injection of CORT with CLEN increased, but PROP reduced p-CREB activities. Our findings show that corticosterone facilitates the acquisition and consolidation of fear memory extinction. GRs and β-adrenoceptors in the IL jointly regulate fear memory extinction via ERK and CREB signaling pathways. This pre-clinical animal study may highlight the effect of GRs and β-adrenoceptors of the IL cortex in regulating fear memory processes in fear-related disorders such as PTSD.
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Affiliation(s)
- Morvarid Meamar
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran
| | - Ali Rashidy-Pour
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran; Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Mehrnoush Rahmani
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran
| | - Abbas Ali Vafaei
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran; Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
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8
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Omoumi S, Rashidy-Pour A, Seyedinia SA, Tarahomi P, Vafaei AA, Raise-Abdullahi P. Corticosterone injection into the infralimbic prefrontal cortex enhances fear memory extinction: Involvement of GABA receptors and the extracellular signal-regulated kinase. Physiol Behav 2023; 265:114156. [PMID: 36918107 DOI: 10.1016/j.physbeh.2023.114156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/08/2023] [Accepted: 03/09/2023] [Indexed: 03/13/2023]
Abstract
This study investigated the interactive effect of glucocorticoid and Gamma-aminobutyric acid (GABA) receptors in the Infralimbic (IL) cortex on fear extinction in rats' auditory fear conditioning task (AFC). Animals received 3 conditioning trial tones (conditioned stimulus, 30 s, 4 kHz, 80 dB) co-terminated with a footshock (unconditioned stimulus, 0.8 mA, 1 s). Extinction testing was conducted over 3 days (Ext 1-3) after conditioning. Intra-IL injection of corticosterone (CORT, 20 ng/0.3 µl/side) was performed 15 min before the first extinction trial (Ext 1) which attenuated auditory fear expression in subsequent extinction trials (Ext 1-3), demonstrating fear memory extinction enhancement. Co-injection of the GABAA agonist muscimol (250 ng/0.3 µl/side) or the GABAB agonist baclofen (250 ng/0.3 µl/side) 15 min before corticosterone, did not significantly affect the facilitative effects of corticosterone on fear extinction. However, co-injection of the GABAA antagonist bicuculline (BIC, 100 ng/0.3 µl/side) or the GABAB antagonist CGP35348 (CGP, 100 ng/0.3 µl/side) 15 min before corticosterone, blocked the facilitative effects of corticosterone on fear extinction. Moreover, extracellular signal-regulated kinase (ERK) and cAMP response element-binding (CREB) in the IL were examined by Western blotting analysis after the first extinction trial (Ext 1) in some groups. Intra-IL injection of corticosterone increased the ERK activity but not CREB. Co-injection of the bicuculline or CGP35348 blocked the enhancing effect of corticosterone on ERK expression in the IL. Glucocorticoid receptors (GRs) activation in the IL cortex by corticosterone increased ERK activity and facilitated fear extinction. GABAA or GABAB antagonists decreased ERK activity and inhibited corticosterone's effect. GRs and GABA receptors in the IL cortex jointly modulate the fear extinction processes via the ERK pathway. This pre-clinical animal study may highlight GRs and GABA interactions in the IL cortex modulating fear memory processes in fear-related disorders such as post-traumatic stress disorder (PTSD).
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Affiliation(s)
- Samira Omoumi
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran; Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Ali Rashidy-Pour
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran; Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Seyed Ali Seyedinia
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran; Student Research Committee, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Parnia Tarahomi
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran; Student Research Committee, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Abbas Ali Vafaei
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran; Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
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Velasco ER, Florido A, Perez-Caballero L, Marin I, Andero R. The Impacts of Sex Differences and Sex Hormones on Fear Extinction. Curr Top Behav Neurosci 2023; 64:105-132. [PMID: 37528309 DOI: 10.1007/7854_2023_426] [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] [Indexed: 08/03/2023]
Abstract
Fear extinction memories are strongly modulated by sex and hormonal status, but the exact mechanisms are still being discovered. In humans, there are some basal and task-related features in which male and female individuals differ in fear conditioning paradigms. However, analyses considering the effects of sex hormones demonstrate a role for estradiol in fear extinction memory consolidation. Translational studies are taking advantage of the convergent findings between species to understand the brain structures implicated. Nevertheless, the human brain is complex and the transfer of these findings into the clinics remains a challenge. The promising advances in the field together with the standardization of fear extinction methodologies in humans will benefit the design of new personalized therapies.
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Affiliation(s)
- Eric Raul Velasco
- Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Antonio Florido
- Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
- Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Laura Perez-Caballero
- Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
- Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Ignacio Marin
- Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Raul Andero
- Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain.
- Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Universitat Autònoma de Barcelona, Barcelona, Spain.
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain.
- Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain.
- ICREA, Pg. Lluís Companys 23, Barcelona, Spain.
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10
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Sex differences in fear responses: Neural circuits. Neuropharmacology 2023; 222:109298. [PMID: 36328063 DOI: 10.1016/j.neuropharm.2022.109298] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/26/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022]
Abstract
Women have increased vulnerability to PTSD and anxiety disorders compared to men. Understanding the neurobiological underpinnings of these disorders is critical for identifying risk factors and developing appropriate sex-specific interventions. Despite the clear clinical relevance of an examination of sex differences in fear responses, the vast majority of pre-clinical research on fear learning and memory formation has exclusively used male animals. This review highlights sex differences in context and cued fear conditioning, fear extinction and fear generalization with a focus on the neural circuits underlying these behaviors in rodents. There are mixed reports of behavioral sex differences in context and cued fear conditioning paradigms, which can depend upon the behavioral indices of fear. However, there is greater evidence of differential activation of the hippocampus, amygdalar nuclei and the prefrontal cortical regions in male and female rodents during context and cued fear conditioning. The bed nucleus of the stria terminalis (BNST), a sexually dimorphic structure, is of particular interest as it differentially contributes to fear responses in males and females. In addition, while the influence of the estrous cycle on different phases of fear conditioning is delineated, the clearest modulatory effect of estrogen is on fear extinction processes. Examining the variability in neural responses and behavior in both sexes should increase our understanding of how that variability contributes to the neurobiology of affective disorders. This article is part of the Special Issue on 'Fear, anxiety and PTSD'.
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11
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Reich N, Hölscher C. Beyond Appetite: Acylated Ghrelin As A Learning, Memory and Fear Behavior-modulating Hormone. Neurosci Biobehav Rev 2022; 143:104952. [DOI: 10.1016/j.neubiorev.2022.104952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 04/27/2022] [Accepted: 11/05/2022] [Indexed: 11/10/2022]
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12
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Ojea Ramos S, Feld M, Fustiñana MS. Contributions of extracellular-signal regulated kinase 1/2 activity to the memory trace. Front Mol Neurosci 2022; 15:988790. [PMID: 36277495 PMCID: PMC9580372 DOI: 10.3389/fnmol.2022.988790] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/02/2022] [Indexed: 11/15/2022] Open
Abstract
The ability to learn from experience and consequently adapt our behavior is one of the most fundamental capacities enabled by complex and plastic nervous systems. Next to cellular and systems-level changes, learning and memory formation crucially depends on molecular signaling mechanisms. In particular, the extracellular-signal regulated kinase 1/2 (ERK), historically studied in the context of tumor growth and proliferation, has been shown to affect synaptic transmission, regulation of neuronal gene expression and protein synthesis leading to structural synaptic changes. However, to what extent the effects of ERK are specifically related to memory formation and stabilization, or merely the result of general neuronal activation, remains unknown. Here, we review the signals leading to ERK activation in the nervous system, the subcellular ERK targets associated with learning-related plasticity, and how neurons with activated ERK signaling may contribute to the formation of the memory trace.
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Affiliation(s)
- Santiago Ojea Ramos
- Instituto de Fisiología, Biología Molecular y Neurociencias, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Mariana Feld
- Instituto de Fisiología, Biología Molecular y Neurociencias, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- *Correspondence: Mariana Feld,
| | - María Sol Fustiñana
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- María Sol Fustiñana,
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13
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Ostroff LE, Cain CK. Persistent up-regulation of polyribosomes at synapses during long-term memory, reconsolidation, and extinction of associative memory. LEARNING & MEMORY (COLD SPRING HARBOR, N.Y.) 2022; 29:192-202. [PMID: 35882501 PMCID: PMC9374273 DOI: 10.1101/lm.053577.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 06/28/2022] [Indexed: 11/25/2022]
Abstract
Local protein synthesis at synapses can provide a rapid supply of proteins to support synaptic changes during consolidation of new memories, but its role in the maintenance or updating of established memories is unknown. Consolidation requires new protein synthesis in the period immediately following learning, whereas established memories are resistant to protein synthesis inhibitors. We have previously reported that polyribosomes are up-regulated in the lateral amygdala (LA) during consolidation of aversive-cued Pavlovian conditioning. In this study, we used serial section electron microscopy reconstructions to determine whether the distribution of dendritic polyribosomes returns to baseline during the long-term memory phase. Relative to control groups, long-term memory was associated with up-regulation of polyribosomes throughout dendrites, including in dendritic spines of all sizes. Retrieval of a consolidated memory by presentation of a small number of cues induces a new, transient requirement for protein synthesis to maintain the memory, while presentation of a large number of cues results in extinction learning, forming a new memory. One hour after retrieval or extinction training, the distribution of dendritic polyribosomes was similar except in the smallest spines, which had more polyribosomes in the extinction group. Our results demonstrate that the effects of learning on dendritic polyribosomes are not restricted to the transient translation-dependent phase of memory formation. Cued Pavlovian conditioning induces persistent synapse strengthening in the LA that is not reversed by retrieval or extinction, and dendritic polyribosomes may therefore correlate generally with synapse strength as opposed to recent activity or transient translational processes.
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Affiliation(s)
- Linnaea E Ostroff
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269, USA.,Connecticut Institute for the Brain and Cognitive Science, University of Connecticut, Storrs, Connecticut 06269, USA.,Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, USA
| | - Christopher K Cain
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, New York 10962, USA.,Child and Adolescent Psychiatry, New York University Langone Health, New York, New York 10016, USA
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14
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Raut SB, Marathe PA, van Eijk L, Eri R, Ravindran M, Benedek DM, Ursano RJ, Canales JJ, Johnson LR. Diverse therapeutic developments for post-traumatic stress disorder (PTSD) indicate common mechanisms of memory modulation. Pharmacol Ther 2022; 239:108195. [PMID: 35489438 DOI: 10.1016/j.pharmthera.2022.108195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 12/20/2022]
Abstract
Post-traumatic stress disorder (PTSD), characterized by abnormally persistent and distressing memories, is a chronic debilitating condition in need of new treatment options. Current treatment guidelines recommend psychotherapy as first line management with only two drugs, sertraline and paroxetine, approved by U.S. Food and Drug Administration (FDA) for treatment of PTSD. These drugs have limited efficacy as they only reduce symptoms related to depression and anxiety without producing permanent remission. PTSD remains a significant public health problem with high morbidity and mortality requiring major advances in therapeutics. Early evidence has emerged for the beneficial effects of psychedelics particularly in combination with psychotherapy for management of PTSD, including psilocybin, MDMA, LSD, cannabinoids, ayahuasca and ketamine. MDMA and psilocybin reduce barrier to therapy by increasing trust between therapist and patient, thus allowing for modification of trauma related memories. Furthermore, research into the memory reconsolidation mechanisms has allowed for identification of various pharmacological targets to disrupt abnormally persistent memories. A number of pre-clinical and clinical studies have investigated novel and re-purposed pharmacological agents to disrupt fear memory in PTSD. Novel therapeutic approaches like neuropeptide Y, oxytocin, cannabinoids and neuroactive steroids have also shown potential for PTSD treatment. Here, we focus on the role of fear memory in the pathophysiology of PTSD and propose that many of these new therapeutic strategies produce benefits through the effect on fear memory. Evaluation of recent research findings suggests that while a number of drugs have shown promising results in preclinical studies and pilot clinical trials, the evidence from large scale clinical trials would be needed for these drugs to be incorporated in clinical practice.
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Affiliation(s)
- Sanket B Raut
- Schools of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia
| | - Padmaja A Marathe
- Department of Pharmacology and Therapeutics, Seth GS Medical College & KEM Hospital, Parel, Mumbai 400 012, India
| | - Liza van Eijk
- Department of Psychology, College of Healthcare Sciences, James Cook University, QLD 4811, Australia
| | - Rajaraman Eri
- Health Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia
| | - Manoj Ravindran
- Medicine, College of Health and Medicine, University of Tasmania, TAS 7250, Australia; Department of Psychiatry, North-West Private Hospital, Burnie TAS 7320, Australia
| | - David M Benedek
- Centre for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD 20814, USA
| | - Robert J Ursano
- Centre for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD 20814, USA
| | - Juan J Canales
- Schools of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia
| | - Luke R Johnson
- Schools of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia; Centre for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD 20814, USA.
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15
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Kawaminami A, Yamada D, Yanagisawa S, Shirakata M, Iio K, Nagase H, Saitoh A. Selective δ-Opioid Receptor Agonist, KNT-127, Facilitates Contextual Fear Extinction via Infralimbic Cortex and Amygdala in Mice. Front Behav Neurosci 2022; 16:808232. [PMID: 35264937 PMCID: PMC8899726 DOI: 10.3389/fnbeh.2022.808232] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 01/10/2022] [Indexed: 11/18/2022] Open
Abstract
Facilitation of fear extinction is a desirable action for the drugs to treat fear-related diseases, such as posttraumatic stress disorder (PTSD). We previously reported that a selective agonist of the δ-opioid receptor (DOP), KNT-127, facilitates contextual fear extinction in mice. However, its site of action in the brain and the underlying molecular mechanism remains unknown. Here, we investigated brain regions and cellular signaling pathways that may mediate the action of KNT-127 on fear extinction. Twenty-four hours after the fear conditioning, mice were reexposed to the conditioning chamber for 6 min as extinction training (reexposure 1). KNT-127 was microinjected into either the basolateral nucleus of the amygdala (BLA), hippocampus (HPC), prelimbic (PL), or infralimbic (IL) subregions of the medial prefrontal cortex, 30 min before reexposure 1. Next day, mice were reexposed to the chamber for 6 min as memory testing (reexposure 2). KNT-127 that infused into the BLA and IL, but not HPC or PL, significantly reduced the freezing response in reexposure 2 compared with those of control. The effect of KNT-127 administered into the BLA and IL was antagonized by pretreatment with a selective DOP antagonist. Further, the effect of KNT-127 was abolished by local administration of MEK/ERK inhibitor into the BLA, and PI3K/Akt inhibitor into the IL, respectively. These results suggested that the effect of KNT-127 was mediated by MEK/ERK signaling in the BLA, PI3K/Akt signaling in the IL, and DOPs in both brain regions. Here, we propose that DOPs play a role in fear extinction via distinct signaling pathways in the BLA and IL.
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Affiliation(s)
- Ayako Kawaminami
- Laboratory of Pharmacology, Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Daisuke Yamada
- Laboratory of Pharmacology, Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
- *Correspondence: Daisuke Yamada,
| | - Shoko Yanagisawa
- Laboratory of Pharmacology, Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Motoki Shirakata
- Laboratory of Pharmacology, Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Keita Iio
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, Japan
| | - Hiroshi Nagase
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, Japan
| | - Akiyoshi Saitoh
- Laboratory of Pharmacology, Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
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16
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Glavonic E, Mitic M, Adzic M. Hallucinogenic drugs and their potential for treating fear-related disorders: Through the lens of fear extinction. J Neurosci Res 2022; 100:947-969. [PMID: 35165930 DOI: 10.1002/jnr.25017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/17/2021] [Accepted: 01/05/2022] [Indexed: 12/29/2022]
Abstract
Fear-related disorders, mainly phobias and post-traumatic stress disorder, are highly prevalent, debilitating disorders that pose a significant public health problem. They are characterized by aberrant processing of aversive experiences and dysregulated fear extinction, leading to excessive expression of fear and diminished quality of life. The gold standard for treating fear-related disorders is extinction-based exposure therapy (ET), shown to be ineffective for up to 35% of subjects. Moreover, ET combined with traditional pharmacological treatments for fear-related disorders, such as selective serotonin reuptake inhibitors, offers no further advantage to patients. This prompted the search for ways to improve ET outcomes, with current research focused on pharmacological agents that can augment ET by strengthening fear extinction learning. Hallucinogenic drugs promote reprocessing of fear-imbued memories and induce positive mood and openness, relieving anxiety and enabling the necessary emotional engagement during psychotherapeutic interventions. Mechanistically, hallucinogens induce dynamic structural and functional neuroplastic changes across the fear extinction circuitry and temper amygdala's hyperreactivity to threat-related stimuli, effectively mitigating one of the hallmarks of fear-related disorders. This paper provides the first comprehensive review of hallucinogens' potential to alleviate symptoms of fear-related disorders by focusing on their effects on fear extinction and the underlying molecular mechanisms. We overview both preclinical and clinical studies and emphasize the advantages of hallucinogenic drugs over current first-line treatments. We highlight 3,4-methylenedioxymethamphetamine and ketamine as the most effective therapeutics for fear-related disorders and discuss the potential molecular mechanisms responsible for their potency with implications for improving hallucinogen-assisted psychotherapy.
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Affiliation(s)
- Emilija Glavonic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Milos Mitic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Miroslav Adzic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
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17
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Awathale SN, Waghade AM, Kawade HM, Jadhav G, Choudhary AG, Sagarkar S, Sakharkar AJ, Subhedar NK, Kokare DM. Neuroplastic Changes in the Superior Colliculus and Hippocampus in Self-rewarding Paradigm: Importance of Visual Cues. Mol Neurobiol 2021; 59:890-915. [PMID: 34797522 DOI: 10.1007/s12035-021-02597-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/11/2021] [Indexed: 12/21/2022]
Abstract
Coincident excitation via different sensory modalities encoding objects of positive salience is known to facilitate learning and memory. With a view to dissect the contribution of visual cues in inducing adaptive neural changes, we monitored the lever press activity of a rat conditioned to self-administer sweet food pellets in the presence/absence of light cues. Application of light cues facilitated learning and consolidation of long-term memory. The superior colliculus (SC) of rats trained on light cue showed increased neuronal activity, dendritic branching, and brain-derived neurotrophic factor (BDNF) protein and mRNA expression. Concomitantly, the hippocampus showed augmented neurogenesis as well as BDNF protein and mRNA expression. While intra-SC administration of U0126 (inhibitor of ERK 1/2 and long-term memory) impaired memory formation, lidocaine (local anaesthetic) hindered memory recall. The light cue-dependent sweet food pellet self-administration was coupled with increased efflux of dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the nucleus accumbens shell (AcbSh). In conditioned rats, pharmacological inhibition of glutamatergic signalling in dentate gyrus (DG) reduced lever press activity, as well as DA and DOPAC secretion in the AcbSh. We suggest that the neuroplastic changes in the SC and hippocampus might represent memory engrams sculpted by visual cues encoding reward information.
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Affiliation(s)
- Sanjay N Awathale
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, 440 033, India
| | - Akash M Waghade
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, 440 033, India
| | - Harish M Kawade
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, 440 033, India
| | - Gouri Jadhav
- Department of Biotechnology, Savitribai Phule Pune University, Pune, 411 007, India
| | - Amit G Choudhary
- Indian Institute of Science Education and Research (IISER), Dr. Homi Bhabha Road, Pune, 411 008, India
| | - Sneha Sagarkar
- Department of Zoology, Savitribai Phule Pune University, Pune, 411 007, India
| | - Amul J Sakharkar
- Department of Biotechnology, Savitribai Phule Pune University, Pune, 411 007, India
| | - Nishikant K Subhedar
- Indian Institute of Science Education and Research (IISER), Dr. Homi Bhabha Road, Pune, 411 008, India
| | - Dadasaheb M Kokare
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, 440 033, India.
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18
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Guadagno A, Belliveau C, Mechawar N, Walker CD. Effects of Early Life Stress on the Developing Basolateral Amygdala-Prefrontal Cortex Circuit: The Emerging Role of Local Inhibition and Perineuronal Nets. Front Hum Neurosci 2021; 15:669120. [PMID: 34512291 PMCID: PMC8426628 DOI: 10.3389/fnhum.2021.669120] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 07/29/2021] [Indexed: 01/10/2023] Open
Abstract
The links between early life stress (ELS) and the emergence of psychopathology such as increased anxiety and depression are now well established, although the specific neurobiological and developmental mechanisms that translate ELS into poor health outcomes are still unclear. The consequences of ELS are complex because they depend on the form and severity of early stress, duration, and age of exposure as well as co-occurrence with other forms of physical or psychological trauma. The long term effects of ELS on the corticolimbic circuit underlying emotional and social behavior are particularly salient because ELS occurs during critical developmental periods in the establishment of this circuit, its local balance of inhibition:excitation and its connections with other neuronal pathways. Using examples drawn from the human and rodent literature, we review some of the consequences of ELS on the development of the corticolimbic circuit and how it might impact fear regulation in a sex- and hemispheric-dependent manner in both humans and rodents. We explore the effects of ELS on local inhibitory neurons and the formation of perineuronal nets (PNNs) that terminate critical periods of plasticity and promote the formation of stable local networks. Overall, the bulk of ELS studies report transient and/or long lasting alterations in both glutamatergic circuits and local inhibitory interneurons (INs) and their associated PNNs. Since the activity of INs plays a key role in the maturation of cortical regions and the formation of local field potentials, alterations in these INs triggered by ELS might critically participate in the development of psychiatric disorders in adulthood, including impaired fear extinction and anxiety behavior.
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Affiliation(s)
- Angela Guadagno
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Claudia Belliveau
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Naguib Mechawar
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Claire-Dominique Walker
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
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19
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Lewis V, Laberge F, Heyland A. Transcriptomic signature of extinction learning in the brain of the fire-bellied toad, Bombina orientalis. Neurobiol Learn Mem 2021; 184:107502. [PMID: 34391934 DOI: 10.1016/j.nlm.2021.107502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/21/2021] [Accepted: 08/08/2021] [Indexed: 11/26/2022]
Abstract
Insight into the molecular and cellular mechanisms of learning and memory from a diverse array of taxa contributes to our understanding of the evolution of these processes. The fire-bellied toad, Bombina orientalis, is a basal anuran amphibian model species who could help us describe shared and divergent characteristics of learning and memory mechanisms between amphibians and other vertebrates, and hence answer questions about the evolution of learning. Utilizing next generation sequencing techniques, we profiled gene expression patterns associated with the extinction of prey-catching conditioning in the brain of the fire-bellied toad. For this purpose, gene expression was at first compared between toads sacrificed after acquisition and extinction of the conditioned response. A second comparison was done between toads submitted to extinction following either short or long acquisition training, which results in toads displaying response extinction or resistance to extinction, respectively. We analyzed brain tissue transcription profiles common to both acquisition and extinction learning, or unique to extinction learning and resistance to extinction, and found significant overlap in gene expression related to molecular pathways involving neuronal plasticity (e.g. structural modification, transcription). However, extinction learning induced a unique GABAergic transcriptomic signal, which may be responsible for suppression of the original response memory. Further, when comparing extinction learning in short- and long-trained groups, short training engaged many pathways related to neuronal plasticity, as expected, but long training engaged molecular pathways related to the suppression of learning through epigenetic mediated transcriptional suppression and inhibitory neurotransmission. Overall, gene expression patterns associated with extinction learning in the fire-bellied toad were similar to those found in mammals submitted to extinction, although some divergent profiles highlighted potential differences in the mechanisms of learning and memory among tetrapods.
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Affiliation(s)
- Vern Lewis
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Frédéric Laberge
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Andreas Heyland
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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20
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Ko MJ, Chiang T, Mukadam AA, Mulia GE, Gutridge AM, Lin A, Chester JA, van Rijn RM. β-Arrestin-dependent ERK signaling reduces anxiety-like and conditioned fear-related behaviors in mice. Sci Signal 2021; 14:14/694/eaba0245. [PMID: 34344831 DOI: 10.1126/scisignal.aba0245] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
G protein-coupled receptors (GPCRs) are implicated in the regulation of fear and anxiety. GPCR signaling involves canonical G protein pathways but can also engage downstream kinases and effectors through scaffolding interactions mediated by β-arrestin. Here, we investigated whether β-arrestin signaling regulates anxiety-like and fear-related behavior in mice in response to activation of the GPCR δ-opioid receptor (δOR or DOR). Administration of β-arrestin-biased δOR agonists to male C57BL/6 mice revealed β-arrestin 2-dependent activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in the dorsal hippocampus and amygdala and β-arrestin 1-dependent activation of ERK1/2 in the nucleus accumbens. In mice, β-arrestin-biased agonist treatment was associated with reduced anxiety-like and fear-related behaviors, with some overlapping and isoform-specific input. In contrast, applying a G protein-biased δOR agonist decreased ERK1/2 activity in all three regions as well as the dorsal striatum and was associated with increased fear-related behavior without effects on baseline anxiety. Our results indicate a complex picture of δOR neuromodulation in which β-arrestin 1- and 2-dependent ERK signaling in specific brain subregions suppresses behaviors associated with anxiety and fear and opposes the effects of G protein-biased signaling. Overall, our findings highlight the importance of noncanonical β-arrestin-dependent GPCR signaling in the regulation of these interrelated emotions.
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Affiliation(s)
- Mee Jung Ko
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA.,Purdue Institute for Integrative Neuroscience, West Lafayette, IN 47907, USA.,Purdue Interdisciplinary Life Sciences Graduate Program, West Lafayette, IN 47907, USA
| | - Terrance Chiang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA
| | - Arbaaz A Mukadam
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA.,Department of Psychological Sciences, College of Health and Human Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Grace E Mulia
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA.,Purdue Interdisciplinary Life Sciences Graduate Program, West Lafayette, IN 47907, USA
| | - Anna M Gutridge
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA.,Purdue Institute for Integrative Neuroscience, West Lafayette, IN 47907, USA
| | - Angel Lin
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA
| | - Julia A Chester
- Purdue Institute for Integrative Neuroscience, West Lafayette, IN 47907, USA.,Purdue Interdisciplinary Life Sciences Graduate Program, West Lafayette, IN 47907, USA.,Department of Psychological Sciences, College of Health and Human Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Richard M van Rijn
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA. .,Purdue Institute for Integrative Neuroscience, West Lafayette, IN 47907, USA.,Purdue Interdisciplinary Life Sciences Graduate Program, West Lafayette, IN 47907, USA.,Purdue Institute for Drug Discovery, West Lafayette, IN 47907, USA
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21
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Dissociable roles of the nucleus accumbens core and shell subregions in the expression and extinction of conditioned fear. Neurobiol Stress 2021; 15:100365. [PMID: 34355048 PMCID: PMC8319794 DOI: 10.1016/j.ynstr.2021.100365] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/23/2021] [Accepted: 07/09/2021] [Indexed: 12/25/2022] Open
Abstract
The nucleus accumbens (NAc), consisting of core (NAcC) and shell (NAcS) sub-regions, has primarily been studied as a locus mediating the effects of drug reward and addiction. However, there is ample evidence that this region is also involved in regulating aversive responses, but the exact role of the NAc and its subregions in regulating associative fear processing remains unclear. Here, we investigated the specific contribution of the NAcC and NAcS in regulating both fear expression and fear extinction in C57BL/6J mice. Using Arc expression as an indicator of neuronal activity, we first show that the NAcC is specifically active only in response to an associative fear cue during an expression test. In contrast, the NAcS is specifically active during fear extinction. We next inactivated each subregion using lidocaine and demonstrated that the NAcC is necessary for fear expression, but not for extinction learning or consolidation of extinction. In contrast, we demonstrate that the NAcS is necessary for the consolidation of extinction, but not fear expression or extinction learning. Further, inactivation of mGluR1 or ERK signaling specifically in the NAcS disrupted the consolidation of extinction but had no effect on fear expression or extinction learning itself. Our data provide the first evidence for the importance of the ERK/MAPK pathway as the underlying neural mechanism facilitating extinction consolidation within the NAcS. These findings suggest that the NAc subregions play dissociable roles in regulating fear recall and the consolidation of fear extinction, and potentially implicate them as critical regions within the canonical fear circuit.
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Askari-Zahabi K, Abbasnejad M, Kooshki R, Esmaeili-Mahani S. Orexin one receptors within the basolateral amygdala are involved in the modulation of cognitive deficits associated with a migraine-like state in rats. Neurol Res 2021; 43:1087-1097. [PMID: 34233602 DOI: 10.1080/01616412.2021.1949687] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES This study explored the possible role of orexin one receptors (Orx1R) in the basolateral amygdala (BLA) on the modulation of nitroglycerin (NTG)-induced migraine-like symptoms. In addition, pain-induced subsequent alteration in learning and memory competence was evaluated in the adult male Wistar rats. METHODS The rats were given NTG (5 mg/kg, i.p.) every two days (for nine-day) to induce a migraine-like state. The migraine animals were treated with intra-BLA infusion of an Orx1R antagonist SB 334,867 (10, 20, and 40 nM/rat) or its vehicle DMSO. The NTG-induced migraine symptoms were recorded for 90 min. Spatial and passive avoidance performances were assessed by Morris water maze (MWM) and shuttle box tasks, respectively. RESULTS In comparison with control, NTG produced significant migraine-like symptoms characterized by a decrease in cage climbing and an increase in head-scratching, freezing, and facial grooming behavior. Intra-BLA infusion of SB 334,867 (40 nM/rat) significantly decreased cage climbing and increased facial grooming responses in NTG-treated rats. Moreover, all administrated doses of SB 334,867 increased NTG-evoked head-scratching and freezing behavior. Besides, NTG impaired learning and memory performances in both tests, which were exaggerated by post-injection of SB 334,867 (40 nM/rat). CONCLUSIONS Overall, the data provided an emerging role for the orexin system within BLA in the modulation of cognitive decline comorbid with migraine in rats.
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Affiliation(s)
- Khadijeh Askari-Zahabi
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Razieh Kooshki
- Department of Biology, Faculty of Sciences, Lorestan University, Khorramabad, Iran
| | - Saeed Esmaeili-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
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23
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Bouton ME, Maren S, McNally GP. BEHAVIORAL AND NEUROBIOLOGICAL MECHANISMS OF PAVLOVIAN AND INSTRUMENTAL EXTINCTION LEARNING. Physiol Rev 2021; 101:611-681. [PMID: 32970967 PMCID: PMC8428921 DOI: 10.1152/physrev.00016.2020] [Citation(s) in RCA: 133] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This article reviews the behavioral neuroscience of extinction, the phenomenon in which a behavior that has been acquired through Pavlovian or instrumental (operant) learning decreases in strength when the outcome that reinforced it is removed. Behavioral research indicates that neither Pavlovian nor operant extinction depends substantially on erasure of the original learning but instead depends on new inhibitory learning that is primarily expressed in the context in which it is learned, as exemplified by the renewal effect. Although the nature of the inhibition may differ in Pavlovian and operant extinction, in either case the decline in responding may depend on both generalization decrement and the correction of prediction error. At the neural level, Pavlovian extinction requires a tripartite neural circuit involving the amygdala, prefrontal cortex, and hippocampus. Synaptic plasticity in the amygdala is essential for extinction learning, and prefrontal cortical inhibition of amygdala neurons encoding fear memories is involved in extinction retrieval. Hippocampal-prefrontal circuits mediate fear relapse phenomena, including renewal. Instrumental extinction involves distinct ensembles in corticostriatal, striatopallidal, and striatohypothalamic circuits as well as their thalamic returns for inhibitory (extinction) and excitatory (renewal and other relapse phenomena) control over operant responding. The field has made significant progress in recent decades, although a fully integrated biobehavioral understanding still awaits.
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Affiliation(s)
- Mark E Bouton
- Department of Psychological Science, University of Vermont, Burlington, Vermont
| | - Stephen Maren
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, Texas
| | - Gavan P McNally
- School of Psychology, University of New South Wales, Sydney, Australia
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24
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An Adolescent Sensitive Period for Threat Responding: Impacts of Stress and Sex. Biol Psychiatry 2021; 89:651-658. [PMID: 33342545 PMCID: PMC7954972 DOI: 10.1016/j.biopsych.2020.10.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 09/30/2020] [Accepted: 10/05/2020] [Indexed: 11/22/2022]
Abstract
Anxiety and fear-related disorders peak in prevalence during adolescence, a window of rapid behavioral development and neural remodeling. However, understanding of the development of threat responding and the underlying neural circuits remains limited. Preclinical models of threat conditioning and extinction have provided an unparalleled glimpse into the developing brain. In this review we discuss mouse and rat studies on the development of threat response regulation, with a focus on the adolescent period. Evidence of nonlinear patterns of threat responding during adolescence and the continued development of the underlying circuitry is highly indicative of an adolescent sensitive period for threat response regulation. While we highlight literature in support of this unique developmental window, we also emphasize the need for causal studies to clarify the parameters defining such a sensitive period. In doing so, we explore how stress and biological sex affect the development and expression of threat response regulation during adolescence and beyond. Ultimately, a deeper understanding of how these factors interact with and affect developmental trajectories of learning and memory will inform treatment and prevention strategies for pediatric anxiety disorders.
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25
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Understanding the dynamic and destiny of memories. Neurosci Biobehav Rev 2021; 125:592-607. [PMID: 33722616 DOI: 10.1016/j.neubiorev.2021.03.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/18/2021] [Accepted: 03/08/2021] [Indexed: 01/16/2023]
Abstract
Memory formation enables the retention of life experiences overtime. Based on previously acquired information, organisms can anticipate future events and adjust their behaviors to maximize survival. However, in an ever-changing environment, a memory needs to be malleable to maintain its relevance. In fact, substantial evidence suggests that a consolidated memory can become labile and susceptible to modifications after being reactivated, a process termed reconsolidation. When an extinction process takes place, a memory can also be temporarily inhibited by a second memory that carries information with opposite meaning. In addition, a memory can fade and lose its significance in a process known as forgetting. Thus, following retrieval, new life experiences can be integrated with the original memory trace to maintain its predictive value. In this review, we explore the determining factors that regulate the fate of a memory after its reactivation. We focus on three post-retrieval memory destinies (reconsolidation, extinction, and forgetting) and discuss recent rodent studies investigating the biological functions and neural mechanisms underlying each of these processes.
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26
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Saha R, Kriebel M, Anunu R, Volkmer H, Richter-Levin G. Intra-amygdala metaplasticity modulation of fear extinction learning. Eur J Neurosci 2020; 55:2455-2463. [PMID: 33305403 DOI: 10.1111/ejn.15080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 12/22/2022]
Abstract
The amygdala is a key brain region involved in emotional memory formation. It is also responsible for memory modulation in other brain areas. Under extreme conditions, amygdala modulation may lead to the generation of abnormal plasticity and trauma-related psychopathologies. However, the amygdala itself is a dynamic brain region, which is amenable to long-term plasticity and is affected by emotional experiences. These alterations may modify the way the amygdala modulates activity and plasticity in other related brain regions, which in turn may alter the animal's response to subsequent challenges in what could be termed as "Behavioral metaplasticity."Because of the reciprocal interactions between the amygdala and other emotion processing regions, such as the medial prefrontal cortex (mPFC) or the hippocampus, experience-induced intra-amygdala metaplasticity could lead to alterations in mPFC-dependent or hippocampus-dependent behaviors. While initiated by alterations within the basolateral amygdala (BLA), such alterations in other brain regions may come to be independent of BLA modulation, thus establishing what may be termed "Trans-regional metaplasticity." In this article, we review evidence supporting the notions of intra-BLA metaplasticity and how this may develop into "Trans-regional metaplasticity." Future research is needed to understand how such dynamic metaplastic alterations contribute to developing psychopathologies, and how this knowledge may be translated into promoting novel interventions in psychopathologies associated with fear, stress, and trauma.
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Affiliation(s)
- Rinki Saha
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Martin Kriebel
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Tübingen, Germany
| | - Rachel Anunu
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Hansjuergen Volkmer
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Tübingen, Germany
| | - Gal Richter-Levin
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.,Department of Psychology, University of Haifa, Haifa, Israel.,The Integrated Brain and Behavior Research Center (IBBRC), University of Haifa, Haifa, Israel
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Active Transition of Fear Memory Phase from Reconsolidation to Extinction through ERK-Mediated Prevention of Reconsolidation. J Neurosci 2020; 41:1288-1300. [PMID: 33293359 DOI: 10.1523/jneurosci.1854-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 11/16/2020] [Accepted: 11/23/2020] [Indexed: 11/21/2022] Open
Abstract
The retrieval of fear memory induces two opposite memory process, i.e., reconsolidation and extinction. Brief retrieval induces reconsolidation to maintain or enhance fear memory, while prolonged retrieval extinguishes this memory. Although the mechanisms of reconsolidation and extinction have been investigated, it remains unknown how fear memory phases are switched from reconsolidation to extinction during memory retrieval. Here, we show that an extracellular signal-regulated kinase (ERK)-dependent memory transition process after retrieval regulates the switch of memory phases from reconsolidation to extinction by preventing induction of reconsolidation in an inhibitory avoidance (IA) task in male mice. First, the transition memory phase, which cancels the induction of reconsolidation, but is insufficient for the acquisition of extinction, was identified after reconsolidation, but before extinction phases. Second, the reconsolidation, transition, and extinction phases after memory retrieval showed distinct molecular and cellular signatures through cAMP responsive element binding protein (CREB) and ERK phosphorylation in the amygdala, hippocampus, and medial prefrontal cortex (mPFC). The reconsolidation phase showed increased CREB phosphorylation, while the extinction phase displayed several neural populations with various combinations of CREB and/or ERK phosphorylation, in these brain regions. Interestingly, the three memory phases, including the transition phase, showed transient ERK activation immediately after retrieval. Most importantly, the blockade of ERK in the amygdala, hippocampus, or mPFC at the transition memory phase disinhibited reconsolidation-induced enhancement of IA memory. These observations suggest that the ERK-signaling pathway actively regulates the transition of memory phase from reconsolidation to extinction and this process functions as a switch that cancels reconsolidation of fear memory.SIGNIFICANCE STATEMENT Retrieval of fear memory induces two opposite memory process; reconsolidation and extinction. Reconsolidation maintains/enhances fear memory, while extinction weakens fear memory. It remains unknown how memory phases are switched from reconsolidation to extinction during retrieval. Here, we identified an active memory transition process functioning as a switch that inhibits reconsolidation. This memory transition phase showed a transient increase of extracellular signal-regulated kinase (ERK) phosphorylation in the amygdala, hippocampus and medial prefrontal cortex (mPFC). Interestingly, inhibition of ERK in these regions at the transition phase disinhibited the reconsolidation-mediated enhancement of inhibitory avoidance (IA) memory. These findings suggest that the transition memory process actively regulates the switch of fear memory phases of fear memory by preventing induction of reconsolidation through the activation of the ERK-signaling pathway.
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Abstract
MicroRNAs as critical regulators of gene expression important for functions including neuronal development, synapse formation, and synaptic plasticity have been linked with the regulation of neurobiological systems that underlie anxiety processing in the brain. In this chapter, we give an update on associative evidence linking regulation of microRNAs with anxiety- and trauma-related disorders. Moving beyond correlative research, functional studies have emerged recently that explore causal relationships between microRNA expression and anxiety-like behavior. It has been demonstrated that experimental up- or downregulation of the candidate microRNAs in important nodes of the anxiety neurocircuitry can indeed modulate anxiety-related behavior in animal models. Improved methodologies for assessing microRNA-mediated modulation have aided such functional studies, revealing a number of anxiety-regulating microRNAs including miR-15a, miR-17-92, miR-34, miR-101, miR-124, miR-135, and miR-155. Important functional target genes of these identified microRNAs are associated with specific neurotransmitter/neuromodulator signaling, neurotrophin (e.g., BDNF) expression and other aspects of synaptic plasticity, as well as with stress-regulatory/hypothalamic-pituitary-axis function. Furthermore, microRNAs have been revealed that are regulated in distinct brain regions following various anxiety-attenuating strategies. These include pharmacological treatments such as antidepressants and other drugs, as well as non-pharmacological interventions such as fear extinction/exposure therapy or positive stimuli such as exposure to environmental enrichment. These are first indications for a role for microRNAs in the mechanism of action of anxiolytic treatments. As research continues, there is much hope that a deeper understanding of the microRNA-mediated mechanisms underlying anxiety-related disorders could open up possibilities for future novel biomarker and treatment strategies.
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Tohyama S, Matsuda S, Mizutani A. Sex-dependent opposite effects of a tropomyosin-related kinase B receptor (TrkB) agonist 7,8-dihydroxyflavone on cued fear extinction in mice. Neurosci Lett 2019; 715:134670. [PMID: 31805374 DOI: 10.1016/j.neulet.2019.134670] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 11/16/2019] [Accepted: 11/30/2019] [Indexed: 12/22/2022]
Abstract
Tropomyosin-related kinase B receptor (TrkB) is one of the new candidate receptors for drugs targeting psychiatric and neurodegenerative disorders. Recently, 7,8-dihydroxyflavone (7,8-DHF) has been identified as a selective TrkB agonist that crosses the blood-brain barrier after oral or intraperitoneal administration, and it enhances cued fear extinction in male rodents. However, its effects on females remain unclear. Preclinical research including both sexes is important for the development of treatment, particularly, for stress-related disorders such as post-traumatic stress disorder because such disorders are more prevalent in women. Therefore, we investigated the effects of 7,8-DHF on cued and contextual fear extinction in both male and female mice. Here we demonstrated that the administration of 7,8-DHF before each extinction session attenuated cued fear extinction in females; conversely, it enhanced cued fear extinction in males. However, administration of 7,8-DHF immediately after each extinction session did not affect cued fear extinction in either sex. Moreover, in contextual fear extinction, administration of 7,8-DHF before each extinction session did not affect fear extinction in either sex. Thus, 7,8-DHF showed sex-dependent opposite effects on cued fear extinction in mice when administered before but not immediately after each extinction session. Our results could contribute to the development of pharmacotherapy involving 7,8-DHF, particularly for stress-related disorders.
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Affiliation(s)
- Suguru Tohyama
- Department of Pharmacotherapeutics, Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo 194-8543, Japan
| | - Shingo Matsuda
- Department of Pharmacotherapeutics, Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo 194-8543, Japan; Department of Cognitive Behavioral Physiology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba, Chiba 260-8670, Japan; Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan.
| | - Akihiro Mizutani
- Department of Pharmacotherapeutics, Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo 194-8543, Japan
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30
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Yamada D, Yanagisawa S, Yoshizawa K, Yanagita S, Oka JI, Nagase H, Saitoh A. Selective agonists of the δ-opioid receptor, KNT-127 and SNC80, act differentially on extinction learning of contextual fear memory in mice. Neuropharmacology 2019; 160:107792. [DOI: 10.1016/j.neuropharm.2019.107792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/16/2019] [Accepted: 09/21/2019] [Indexed: 01/19/2023]
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31
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Russo AS, Lee J, Parsons RG. Individual variability in the recall of fear extinction is associated with phosphorylation of mitogen-activated protein kinase in the infralimbic cortex. Psychopharmacology (Berl) 2019; 236:2039-2048. [PMID: 30798403 DOI: 10.1007/s00213-019-05195-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/07/2019] [Indexed: 01/31/2023]
Abstract
RATIONALE Although most individuals will be exposed to trauma at some point, only a small portion of individuals develops posttraumatic stress disorder (PTSD), suggesting there are factors which render some individuals particularly susceptible to the development of this disorder. One cardinal feature of PTSD is the failure to extinguish fear responses to cues that once signaled danger. Rodent studies of fear learning and extinction have provided insight into the neural mechanisms underlying extinction; however, most of these studies have focused on mechanisms involved in typical responses and fewer have identified mechanisms that distinguish animals that extinguish well versus those that do not extinguish their fear responses. Investigation of individual differences in fear extinction might help us better understand the susceptibility to and development of PTSD. OBJECTIVES In order to understand the neural mechanisms underlying such variation, we assessed phosphorylated mitogen-activated protein kinase (P-MAPK) levels in infralimbic cortex (IL), basolateral amygdala (BLA), and dorsal hippocampus in subsets of rats which exhibited good or poor recall of extinction. RESULTS We found a relationship between extinction recall and P-MAPK in the IL such that rats which had good extinction recall had higher levels of P-MAPK than those which had poor extinction recall. We also found that rats which had good extinction recall had higher levels of P-MAPK in the dorsal hippocampus than control rats. CONCLUSIONS Our findings suggest that individual differences in the recall of extinction learning can be explained by altered cell signaling in the IL.
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Affiliation(s)
- Amanda S Russo
- Department of Psychology, Stony Brook University, 100 Nicolls Rd., Stony Brook, NY, 11794, USA
| | - Jessica Lee
- Department of Psychology, Stony Brook University, 100 Nicolls Rd., Stony Brook, NY, 11794, USA
| | - Ryan G Parsons
- Department of Psychology, Stony Brook University, 100 Nicolls Rd., Stony Brook, NY, 11794, USA.
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32
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Velasco ER, Florido A, Milad MR, Andero R. Sex differences in fear extinction. Neurosci Biobehav Rev 2019; 103:81-108. [PMID: 31129235 DOI: 10.1016/j.neubiorev.2019.05.020] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/08/2019] [Accepted: 05/19/2019] [Indexed: 12/18/2022]
Abstract
Despite the exponential increase in fear research during the last years, few studies have included female subjects in their design. The need to include females arises from the knowledge gap of mechanistic processes underlying the behavioral and neural differences observed in fear extinction. Moreover, the exact contribution of sex and hormones in relation to learning and behavior is still largely unknown. Insights from this field could be beneficial as fear-related disorders are twice as prevalent in women compared to men. Here, we review an up-to-date summary of animal and human studies in adulthood that report sex differences in fear extinction from a structural and functional approach. Furthermore, we describe how these factors could contribute to the observed sex differences in fear extinction during normal and pathological conditions.
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Affiliation(s)
- E R Velasco
- Institut de Neurociències, Universitat Autònoma de Barcelona, Spain
| | - A Florido
- Institut de Neurociències, Universitat Autònoma de Barcelona, Spain
| | - M R Milad
- Department of Psychiatry, University of Illinois at Chicago, USA
| | - R Andero
- Institut de Neurociències, Universitat Autònoma de Barcelona, Spain; CIBERSAM, Corporació Sanitaria Parc Taulí, Sabadell, Spain; Department of Psychobiology and Methodology of Health Sciences, Universitat Autònoma de Barcelona, Spain.
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33
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Goodman J, Packard MG. There Is More Than One Kind of Extinction Learning. Front Syst Neurosci 2019; 13:16. [PMID: 31133825 PMCID: PMC6514057 DOI: 10.3389/fnsys.2019.00016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 04/12/2019] [Indexed: 01/15/2023] Open
Abstract
The view that different kinds of memory are mediated by dissociable neural systems has received extensive experimental support. Dissociations between memory systems are usually observed during initial acquisition, consolidation, and retrieval of memory, however increasing evidence also indicates a role for multiple memory systems in extinction behavior. The present article reviews a recent series of maze learning experiments that provide evidence for a multiple memory systems approach to extinction learning and memory. Evidence is described indicating that: (1) the hippocampus and dorsolateral striatum (DLS) mediate different kinds of extinction learning; (2) the effectiveness of different extinction protocols depends on the kind of memory being extinguished; and (3) whether a neural system is involved in extinction is also determined by the extinction protocol and kind of memory undergoing extinction. Based on these findings, a novel hypothetical model regarding the role of multiple memory systems in extinction is presented. In addition, the relevance of this multiple memory systems approach to other learning paradigms involving extinction (i.e., extinction of conditioned fear) and for treating human psychopathologies characterized by maladaptive memories (e.g., drug addiction and relapse) is briefly considered.
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Affiliation(s)
- Jarid Goodman
- Department of Psychology, Delaware State University, Dover, DE, United States
| | - Mark G. Packard
- Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX, United States
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34
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Pagani MR, Merlo E. Kinase and Phosphatase Engagement Is Dissociated Between Memory Formation and Extinction. Front Mol Neurosci 2019; 12:38. [PMID: 30842725 PMCID: PMC6391346 DOI: 10.3389/fnmol.2019.00038] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/31/2019] [Indexed: 01/18/2023] Open
Abstract
Associative long-term memories (LTMs) support long-lasting behavioral changes resulting from sensory experiences. Retrieval of a stable LTM by means of a large number of conditioned stimulus (CS) alone presentations produces inhibition of the original memory through extinction. Currently, there are two opposing hypotheses to account for the neural mechanisms supporting extinction. The unlearning hypothesis posits that extinction affects the original memory trace by reverting the synaptic changes supporting LTM. On the contrary, the new learning hypothesis proposes that extinction is simply the formation of a new associative memory that inhibits the expression of the original one. We propose that detailed analysis of extinction-associated molecular mechanisms could help distinguish between these hypotheses. Here we will review experimental evidence regarding the role of protein kinases and phosphatases (K&P) on LTM formation and extinction. Even though K&P regulate both memory processes, their participation appears to be dissociated. LTM formation recruits kinases, but is constrained by phosphatases. Memory extinction presents a more diverse molecular landscape, requiring phosphatases and some kinases, but also being constrained by kinase activity. Based on the available evidence, we propose a new theoretical model for memory extinction: a neuronal segregation of K&P supports a combination of time-dependent reversible inhibition of the original memory [CS-unconditioned stimulus (US)], with establishment of a new associative memory trace (CS-noUS).
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Affiliation(s)
- Mario Rafael Pagani
- Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-Houssay, Facultad de Medicina, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Emiliano Merlo
- Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-Houssay, Facultad de Medicina, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Department of Psychology, University of Cambridge, Cambridge, United Kingdom
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35
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Lingawi NW, Laurent V, Westbrook RF, Holmes NM. The role of the basolateral amygdala and infralimbic cortex in (re)learning extinction. Psychopharmacology (Berl) 2019; 236:303-312. [PMID: 29959461 DOI: 10.1007/s00213-018-4957-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 06/19/2018] [Indexed: 11/25/2022]
Abstract
The basolateral amygdala complex (BLA) and infralimbic region of the prefrontal cortex (IL) play distinct roles in the extinction of Pavlovian conditioned fear in laboratory rodents. In the past decade, research in our laboratory has examined the roles of these brain regions in the re-extinction of conditioned fear: i.e., extinction of fear that is restored through re-conditioning of the conditioned stimulus (CS) or changes in the physical and temporal context of extinction training (i.e., extinction of renewed or spontaneously recovered fear). This paper reviews this research. It has revealed two major findings. First, in contrast to the acquisition of fear extinction, which usually requires neuronal activity in the BLA but not IL, the acquisition of fear re-extinction requires neuronal activity in the IL but can occur independently of neuronal activity in the BLA. Second, the role of the IL in fear extinction is determined by the training history of the CS: i.e., if the CS was novel prior to its fear conditioning (i.e., it had not been trained), the acquisition of fear extinction does not require the IL; if, however, the prior training of the CS included a series of CS-alone exposures (e.g., if the CS had been pre-exposed), the acquisition of fear extinction was facilitated by pharmacological stimulation of the IL. Together, these results were taken to imply that a memory of CS-alone exposures is stored in the IL, survives fear conditioning of the CS, and can be retrieved and strengthened during extinction or re-extinction of that CS (regardless of whether the extinction is first- or second-learned). Hence, under these circumstances, the initial extinction of fear to the CS can be facilitated by pharmacological stimulation of the IL, and re-extinction of fear to the CS can occur in the absence of a functioning BLA.
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Affiliation(s)
- Nura W Lingawi
- School of Psychology, University of New South Wales, Kensington, Sydney, NSW, 2052, Australia
| | - Vincent Laurent
- School of Psychology, University of New South Wales, Kensington, Sydney, NSW, 2052, Australia
| | - R Fredrick Westbrook
- School of Psychology, University of New South Wales, Kensington, Sydney, NSW, 2052, Australia
| | - Nathan M Holmes
- School of Psychology, University of New South Wales, Kensington, Sydney, NSW, 2052, Australia.
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36
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Jacques A, Chaaya N, Hettiarachchi C, Carmody ML, Beecher K, Belmer A, Chehrehasa F, Bartlett S, Battle AR, Johnson LR. Microtopography of fear memory consolidation and extinction retrieval within prefrontal cortex and amygdala. Psychopharmacology (Berl) 2019; 236:383-397. [PMID: 30610350 DOI: 10.1007/s00213-018-5068-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/04/2018] [Indexed: 10/27/2022]
Abstract
RATIONALE The precise neural circuitry that encodes fear memory and its extinction within the brain are not yet fully understood. Fearful memories can be persistent, resistant to extinction, and associated with psychiatric disorders, especially post-traumatic stress disorder (PTSD). Here, we investigated the microtopography of neurons activated during the recall of an extinguished fear memory, as well as the influence of time on this microtopography. METHODS We used the plasticity-related phosphorylated mitogen-activated protein kinase (pMAPK) to identify neurons activated in the recall of consolidated and extinguished auditory Pavlovian fear memories in rats. Quantitatively matched brain regions were used to investigate activity in the amygdala and prefrontal cortex. RESULTS Recall of a consolidated, nonextinguished auditory fear memory resulted in a significantly greater number of activated neurons located in the dorsolateral subdivision of the lateral amygdala (LADL) when recalled 24 h after consolidation but not when recalled 7 days later. We found that the recall of an extinction memory was associated with pMAPK activation in the ventrolateral subdivision of the lateral amygdala (LAVL). Next, we showed that the pattern of pMAPK expression in the prelimbic cortex differed spatially following temporal variation in the recall of that memory. The deep and superficial layers of the pre-limbic cortex were engaged in recent recall of a fear memory, but only the superficial layers were recruited if the recall occurred 7 days later. CONCLUSIONS Collectively, our findings demonstrate a functional microtopography of auditory fear memory during consolidation and extinction at the microanatomical level within the lateral amygdala and medial prefrontal cortex.
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Affiliation(s)
- Angela Jacques
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia.,Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Nicholas Chaaya
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia.,Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Chiemi Hettiarachchi
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Marie-Louise Carmody
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia.,Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kate Beecher
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Arnauld Belmer
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Fatemeh Chehrehasa
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Selena Bartlett
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Andrew R Battle
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia.,The University of Queensland Diamantina Institute, Brisbane, Australia
| | - Luke R Johnson
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia. .,Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia. .,Center for the Study of Traumatic Stress, Department of Psychiatry, USU School of Medicine, Bethesda, MD, USA.
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Wellman CL, Moench KM. Preclinical studies of stress, extinction, and prefrontal cortex: intriguing leads and pressing questions. Psychopharmacology (Berl) 2019; 236:59-72. [PMID: 30225660 PMCID: PMC6374178 DOI: 10.1007/s00213-018-5023-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 09/03/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND Stress is associated with cognitive and emotional dysfunction, and increases risk for a variety of psychological disorders, including depression and posttraumatic stress disorder. Prefrontal cortex is critical for executive function and emotion regulation, is a target for stress hormones, and is implicated in many stress-influenced psychological disorders. Extinction of conditioned fear provides an excellent model system for examining how stress-induced changes in corticolimbic structure and function are related to stress-induced changes in neural function and behavior, as the neural circuitry underlying this behavior is well characterized. OBJECTIVES This review examines how acute and chronic stress influences extinction and describes how stress alters the structure and function of the medial prefrontal cortex, a potential neural substrate for these effects. In addition, we identify important unanswered questions about how stress-induced change in prefrontal cortex may mediate extinction deficits and avenues for future research. KEY FINDINGS A substantial body of work demonstrates deficits in extinction after either acute or chronic stress. A separate and substantial literature demonstrates stress-induced neuronal remodeling in medial prefrontal cortex, along with several key neurohormonal contributors to this remodeling, and there is substantial overlap in prefrontal mechanisms underlying extinction and the mechanisms implicated in stress-induced dysfunction of-and neuronal remodeling in-medial prefrontal cortex. However, data directly examining the contribution of changes in prefrontal structure and function to stress-induced extinction deficits is currently lacking. CONCLUSIONS Understanding how stress influences extinction and its neural substrates as well as individual differences in this effect will elucidate potential avenues for novel interventions for stress-sensitive disorders characterized by deficits in extinction.
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Affiliation(s)
- Cara L. Wellman
- Department of Psychological & Brain Sciences, Indiana University,Department of Psychological, Center for the Integrative Study of Animal Behavior, Indiana University,Department of Psychological, Program in Neuroscience, Indiana University
| | - Kelly M. Moench
- Department of Psychological & Brain Sciences, Indiana University,Department of Psychological, Center for the Integrative Study of Animal Behavior, Indiana University,Department of Psychological, Program in Neuroscience, Indiana University
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Baker KD, McNally GP, Richardson R. d-Cycloserine facilitates fear extinction in adolescent rats and differentially affects medial and lateral prefrontal cortex activation. Prog Neuropsychopharmacol Biol Psychiatry 2018; 86:262-269. [PMID: 29928912 DOI: 10.1016/j.pnpbp.2018.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/02/2018] [Accepted: 06/16/2018] [Indexed: 10/28/2022]
Abstract
Adolescent humans and rodents are impaired in extinguishing learned fear relative to younger and older groups. This impairment could be due to differences in recruitment of medial prefrontal cortex (PFC), orbitofrontal cortex (OFC), or amygdala during extinction. For example, unlike juveniles and adults, adolescent rats do not express extinction-induced increases in phosphorylated mitogen activated protein kinase (pMAPK), a marker of synaptic plasticity, in the medial PFC. The NMDA receptor partial agonist d-cycloserine (DCS) improves extinction retention in adolescent rats. We investigated whether DCS affected recruitment of the PFC and amygdala during extinction by measuring pMAPK-immunoreactive (IR) neurons. Adolescent rats were trained to fear a conditioned stimulus in one context followed by extinction in a second context or equivalent context exposure only (i.e., no extinction). DCS (15 mg/kg, s.c.) or saline was administered systemically immediately after extinction training or context exposure. DCS enhanced extinction learning and this was associated with increased activation of the MAPK signaling pathway in the OFC after extinction training and increased activation in the medial PFC and amygdala at extinction retention. These findings suggest that DCS improves extinction learning in adolescents because it augments OFC contributions to extinction learning, enabling better medial prefrontal contributions to extinction retention.
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Abstract
Overcoming aversive emotional memories requires neural systems that detect when fear responses are no longer appropriate so that they can be extinguished. The midbrain ventral tegmental area (VTA) dopamine system has been implicated in reward and more broadly in signaling when a better-than-expected outcome has occurred. This suggests that it may be important in guiding fear to safety transitions. We report that when an expected aversive outcome does not occur, activity in midbrain dopamine neurons is necessary to extinguish behavioral fear responses and engage molecular signaling events in extinction learning circuits. Furthermore, a specific dopamine projection to the nucleus accumbens medial shell is partially responsible for this effect. In contrast, a separate dopamine projection to the medial prefrontal cortex opposes extinction learning. This demonstrates a novel function for the canonical VTA-dopamine reward system and reveals opposing behavioral roles for different dopamine neuron projections in fear extinction learning. Fear memories are overcome only when it is ascertained that fearful responses are not appropriate. Here the authors demonstrate that activity in dopamine neurons is necessary to extinguish fear responses and two distinct dopamine neuron projections exert opposing effects on extinction learning.
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40
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Activation of a novel p70 S6 kinase 1-dependent intracellular cascade in the basolateral nucleus of the amygdala is required for the acquisition of extinction memory. Mol Psychiatry 2018; 23:1394-1401. [PMID: 28461701 PMCID: PMC5668214 DOI: 10.1038/mp.2017.99] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 12/13/2022]
Abstract
Repeated presentations of a previously conditioned stimulus lead to a new form of learning known as extinction, which temporarily alters the response to the original stimulus. Previous studies have shown that the consolidation of extinction memory requires de novo protein synthesis. However, the role of specific nodes of translational control in extinction is unknown. Using auditory threat conditioning in mice, we investigated the role of mechanistic target of rapamycin complex 1 (mTORC1) and its effector p70 S6 kinase 1 (S6K1) in the extinction of auditory threat conditioning. We found that rapamycin attenuated the consolidation of extinction memory. In contrast, genetic deletion and pharmacological inhibition of S6K1, a downstream effector of mTORC1, blocked within-session extinction, indicating a role for S6K1 independent of protein synthesis. Indeed, the activation of S6K1 during extinction required extracellular signal-regulated kinase (ERK) activation in the basolateral nucleus of the amygdala (BLA) and was necessary for increased phosphorylation of the GluA1 (Thr840) subunit of the AMPA receptor following extinction training. Mice exposed to brief uncontrollable stress showed impaired within-session extinction as well as a downregulation of ERK and S6K1 signaling in the amygdala. Finally, using fiber photometry we were able to record calcium signals in vivo, and we found that inhibition of S6K1 reduces extinction-induced changes in neuronal activity of the BLA. These results implicate a novel ERK-S6K1-GluA1 signaling cascade critically involved in extinction.
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Mechanisms of Sex Differences in Fear and Posttraumatic Stress Disorder. Biol Psychiatry 2018; 83:876-885. [PMID: 29331353 DOI: 10.1016/j.biopsych.2017.11.016] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 11/24/2022]
Abstract
Following sexual maturity, females disproportionately have higher rates of posttraumatic stress disorder (PTSD) and experience greater symptom severity and chronicity as compared with males. This observation has led many to examine sex differences in PTSD risk factors. Though relatively few, these studies reveal that the root causes of PTSD sex differences are complex, and partly represent interactions between sex-specific nonbiological and biological risk factors, which differentially shape PTSD vulnerability. Moreover, these studies suggest that sex-specific PTSD vulnerability is partly regulated by sex differences in fear systems. Fear, which represents a highly conserved adaptive response to threatening environmental stimuli, becomes pathological in trauma- and stress-based psychiatric syndromes, such as PTSD. Over the last 30 years, considerable progress has been made in understanding normal and pathological molecular and behavioral fear processes in humans and animal models. Thus, fear mechanisms represent a tractable PTSD biomarker in the study of sex differences in fear. In this review, we discuss studies that examine nonbiological and biological sex differences that contribute to normal and pathological fear behaviors in humans and animal models. This, we hope, will shed greater light on the potential mechanisms that contribute to increased PTSD vulnerability in females.
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42
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Merlo E, Milton AL, Everitt BJ. A Novel Retrieval-Dependent Memory Process Revealed by the Arrest of ERK1/2 Activation in the Basolateral Amygdala. J Neurosci 2018; 38:3199-3207. [PMID: 29476015 PMCID: PMC6596053 DOI: 10.1523/jneurosci.3273-17.2018] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 01/11/2018] [Accepted: 01/16/2018] [Indexed: 02/02/2023] Open
Abstract
Fully consolidated fear memories can be maintained or inhibited by retrieval-dependent mechanisms depending on the degree of re-exposure to fear cues. Short exposures promote memory maintenance through reconsolidation, and long exposures promote inhibition through extinction. Little is known about the neural mechanisms by which increasing cue exposure overrides reconsolidation and instead triggers extinction. Using auditory fear conditioning in male rats, we analyzed the role of a molecular mechanism common to reconsolidation and extinction of fear, ERK1/2 activation within the basolateral amygdala (BLA), after intermediate conditioned stimulus (CS) exposure events. We show that an intermediate re-exposure (four CS presentations) failed to activate ERK1/2 in the BLA, suggesting the absence of reconsolidation or extinction mechanisms. Supporting this hypothesis, pharmacologically inhibiting the BLA ERK1/2-dependent signaling pathway in conjunction with four CS presentations had no effect on fear expression, and the NMDA receptor partial agonist d-cycloserine, which enhanced extinction and ERK1/2 activation in partial extinction protocols (seven CSs), had no behavioral or molecular effect when given in association with four CS presentations. These molecular and behavioral data reveal a novel retrieval-dependent memory phase occurring along the transition between conditioned fear maintenance and inhibition. CS-dependent molecular events in the BLA may arrest reconsolidation intracellular signaling mechanism in an extinction-independent manner. These findings are critical for understanding the molecular underpinnings of fear memory persistence after retrieval both in health and disease.SIGNIFICANCE STATEMENT Consolidated fear memories can be altered by retrieval-dependent mechanisms. Whereas a brief conditioned stimulus (CS) exposure promotes fear memory maintenance through reconsolidation, a prolonged exposure engages extinction and fear inhibition. The nature of this transition and whether an intermediate degree of CS exposure engages reconsolidation or extinction is unknown. We show that an intermediate cue exposure session (four CSs) produces the arrest of ERK1/2 activation in the basolateral amygdala, a common mechanism for reconsolidation and extinction. Amnestic or hypermnestic treatments given in association with four CSs had no behavioral or molecular effects, respectively. This evidence reveals a novel retrieval-dependent memory phase. Intermediate degrees of CS exposure fail to trigger reconsolidation or extinction, leaving the original memory in an insensitive state.
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Affiliation(s)
- Emiliano Merlo
- Behavioural and Clinical Neuroscience Institute and
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
| | - Amy L Milton
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
| | - Barry J Everitt
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
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43
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Hashimoto M, Hossain S, Katakura M, Mamun AA, Shido O. Docosahexaenoic Acid Helps to Lessen Extinction Memory in Rats. Molecules 2018; 23:molecules23020451. [PMID: 29463009 PMCID: PMC6017742 DOI: 10.3390/molecules23020451] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 02/06/2018] [Accepted: 02/10/2018] [Indexed: 11/16/2022] Open
Abstract
Abstract: Memory extinction is referred to as a learning process in which a conditioned response (CR) progressively reduces over time as an animal learns to uncouple a response from a stimulus. Extinction occurs when the rat is placed into a context without shock after training. Docosahexaenoic acid (DHA, C22:6, n-3) is implicated in memory formation in mammalian brains. In a two-way active shuttle-avoidance apparatus, we examined whether DHA affects the extinction memory and the expression of brain cognition-related proteins, including gastrin-releasing peptide receptor (GRPR), brain-derived neurotrophic factor receptor (BDNFR) tyrosine kinase receptor B (TrKB), and N-methyl-d-aspartate receptor (NMDAR) subunits NR2A and NR2B. Also, the protein levels of GRP, BDNF, postsynaptic density protein-95 (PSD-95), and vesicular acetylcholine transporter (VAChT), and the antioxidative potentials, in terms of lipid peroxide (LPO) and reactive oxygen species (ROS), were examined in the hippocampus. During the acquisition phase, the rats received a conditioned stimulus (CS-tone) paired with an unconditioned stimulus (UCS foot shock) for three consecutive days (Sessions S1, S2, and S3, each consisting of 30-trials) after 12 weeks of oral administration of DHA. After a three-day interval, the rats were re-subjected to two extinction sessions (S4, S5), each comprising 30 trials of CS alone. During the acquisition training in S1, the shock-related avoidance frequency (acquisition memory) was significantly higher in the DHA-administered rats compared with the control rats. The avoidance frequency, however, decreased with successive acquisition trainings in sessions S2 and S3. When the rats were subjected to the extinction sessions after a break for consolidation, the conditioned response (CR) was also significantly higher in the DHA-administered rats. Interestingly, the freezing responses (frequency and time) also significantly decreased in the DHA-administered rats, thus suggesting that a higher coping capacity was present during fear stress in the DHA-administered rats. DHA treatments increased the mRNA levels of GRPR, BDNF receptor TrKB, and NMDAR subunit NR2B. DHA also increased the protein levels of GRP, BDNF, PSD-95, and VAChT, and the antioxidative potentials in the hippocampus. These results suggest the usefulness of DHA for treating stress disorders.
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Affiliation(s)
- Michio Hashimoto
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan.
| | - Shahdat Hossain
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan.
- Department of Biochemistry & Molecular Biology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh.
| | - Masanori Katakura
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan.
| | - Abdullah Al Mamun
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan.
| | - Osamu Shido
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan.
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Memory Retention Involves the Ventrolateral Orbitofrontal Cortex: Comparison with the Basolateral Amygdala. Neuropsychopharmacology 2018; 43:373-383. [PMID: 28664926 PMCID: PMC5729558 DOI: 10.1038/npp.2017.139] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 06/16/2017] [Accepted: 06/19/2017] [Indexed: 11/08/2022]
Abstract
The orbitofrontal cortex (OFC) is thought to link stimuli and actions with anticipated outcomes in order to sustain flexible behavior in an ever-changing environment. How it retains these associations to guide future behavior is less well-defined. Here we focused on one subregion of this heterogeneous structure, the ventrolateral OFC (VLO). CaMKII-driven inhibitory Gi-coupled designer receptors exclusively activated by designer drugs (DREADDs) were infused and subsequently activated by their ligand Clozapine-N-oxide (CNO) in conjunction with fear extinction training (a form of aversive conditioning) and response-outcome conditioning (a form of appetitive conditioning). Gi-DREADD-mediated inactivation of the VLO during extinction conditioning interfered with fear extinction memory, resulting in sustained freezing when mice were later tested drug-free. Similarly, Gi-DREADD-mediated inactivation in conjunction with response-outcome conditioning caused a later decay in goal-directed responding-that is, mice were unable to select actions based on the likelihood that they would be rewarded in a sustainable manner. By contrast, inhibitory Gi-DREADDs in the basolateral amygdala (BLA) impaired the acquisition of both conditioned fear extinction and response-outcome conditioning, as expected based on prior studies using other inactivation techniques. Meanwhile, DREADD-mediated inhibition of the dorsolateral striatum enhanced response-outcome conditioning, also in line with prior reports. Together, our findings suggest that learning-related neuroplasticity in the VLO may be necessary for memory retention in both appetitive and aversive domains.
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45
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Zbukvic IC, Hyun Kim J. Divergent prefrontal dopaminergic mechanisms mediate drug- and fear-associated cue extinction during adolescence versus adulthood. Eur Neuropsychopharmacol 2018; 28:1-12. [PMID: 29174948 DOI: 10.1016/j.euroneuro.2017.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/08/2017] [Accepted: 11/03/2017] [Indexed: 01/21/2023]
Abstract
Cue-associated learning is vital to guiding behaviour for survival. Adolescence represents a key developmental stage for perturbations in cue-related learning, including a characteristic deficit in cue extinction learning. The present review summarizes evidence from animal and human literature that cue extinction is critically mediated by prefrontal dopamine, a system that undergoes dramatic reorganization during adolescence. We propose that extinction learning and memory is governed by a developmentally dynamic balance of dopamine receptors in the prefrontal cortex, which changes across adolescence into adulthood. This is contrary to the previous idea that extinction deficits during adolescence reflect inefficiency in the same neural circuitry as adults. This leads to proposal of the novel theory that cue extinction involves divergent prefrontal dopaminergic mechanisms depending on the age of extinction.
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Affiliation(s)
- Isabel C Zbukvic
- Black Dog Institute, Randwick 2031, NSW, Australia; Behavioral Neuroscience Division, The Florey Institute of Neuroscience & Mental Health, Parkville 3051, VIC, Australia.
| | - Jee Hyun Kim
- Behavioral Neuroscience Division, The Florey Institute of Neuroscience & Mental Health, Parkville 3051, VIC, Australia; The Florey Department of Neuroscience & Mental Health, University of Melbourne, Parkville 3010, VIC, Australia
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46
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Murphy CP, Singewald N. Potential of microRNAs as novel targets in the alleviation of pathological fear. GENES BRAIN AND BEHAVIOR 2017; 17:e12427. [DOI: 10.1111/gbb.12427] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/20/2017] [Accepted: 10/05/2017] [Indexed: 12/16/2022]
Affiliation(s)
- C. P. Murphy
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck; University of Innsbruck; Innsbruck Austria
| | - N. Singewald
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck; University of Innsbruck; Innsbruck Austria
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Datta S, Oliver MD. Cellular and Molecular Mechanisms of REM Sleep Homeostatic Drive: A Plausible Component for Behavioral Plasticity. Front Neural Circuits 2017; 11:63. [PMID: 28959190 PMCID: PMC5603703 DOI: 10.3389/fncir.2017.00063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 08/29/2017] [Indexed: 01/09/2023] Open
Abstract
Homeostatic regulation of REM sleep drive, as measured by an increase in the number of REM sleep transitions, plays a key role in neuronal and behavioral plasticity (i.e., learning and memory). Deficits in REM sleep homeostatic drive (RSHD) are implicated in the development of many neuropsychiatric disorders. Yet, the cellular and molecular mechanisms underlying this RSHD remain to be incomplete. To further our understanding of this mechanism, the current study was performed on freely moving rats to test a hypothesis that a positive interaction between extracellular-signal-regulated kinase 1 and 2 (ERK1/2) activity and brain-derived neurotrophic factor (BDNF) signaling in the pedunculopontine tegmentum (PPT) is a causal factor for the development of RSHD. Behavioral results of this study demonstrated that a short period (<90 min) of selective REM sleep restriction (RSR) exhibited a strong RSHD. Molecular analyses revealed that this increased RSHD increased phosphorylation and activation of ERK1/2 and BDNF expression in the PPT. Additionally, pharmacological results demonstrated that the application of the ERK1/2 activation inhibitor U0126 into the PPT prevented RSHD and suppressed BDNF expression in the PPT. These results, for the first time, suggest that the positive interaction between ERK1/2 and BDNF in the PPT is a casual factor for the development of RSHD. These findings provide a novel direction in understanding how RSHD-associated specific molecular changes can facilitate neuronal plasticity and memory processing.
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Affiliation(s)
- Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, Graduate School of Medicine, Department of Anesthesiology, The University of TennesseeKnoxville, TN, United States.,Department of Psychology, College of Arts and Sciences, The University of TennesseeKnoxville, TN, United States
| | - Michael D Oliver
- Laboratory of Sleep and Cognitive Neuroscience, Graduate School of Medicine, Department of Anesthesiology, The University of TennesseeKnoxville, TN, United States.,Department of Psychology, College of Arts and Sciences, The University of TennesseeKnoxville, TN, United States
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48
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Predictable Chronic Mild Stress during Adolescence Promotes Fear Memory Extinction in Adulthood. Sci Rep 2017; 7:7857. [PMID: 28798340 PMCID: PMC5552791 DOI: 10.1038/s41598-017-08017-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 07/03/2017] [Indexed: 01/16/2023] Open
Abstract
Early-life stress in adolescence has a long-lasting influence on brain function in adulthood, and it is mostly recognized as a predisposing factor for mental illnesses, such as anxiety and posttraumatic stress disorder. Previous studies also indicated that adolescent predictable chronic mild stress (PCMS) in early life promotes resilience to depression- and anxiety-like behaviors in adulthood. However, the role of PCMS in associated memory process is still unclear. In the present study, we found that adolescent PCMS facilitated extinction and inhibited fear response in reinstatement and spontaneous recovery tests in adult rats, and this effect was still present 1 week later. PCMS in adolescence increased the activity of brain-derived neurotrophic factor (BDNF)-extracellular signal-regulated kinase 1/2 (ERK1/2) signaling in infralimbic cortex (IL) but not prelimbic cortex in adulthood. Intra-IL infusion of BDNF antibody and the ERK1/2 inhibitor U0126 reversed PCMS-induced enhancement of fear extinction. Moreover, we found that PCMS decreased DNA methylation of the Bdnf gene at exons IV and VI and elevated the mRNA levels of Bdnf in the IL. Our findings indicate that adolescent PCMS exposure promotes fear memory extinction in adulthood, which reevaluates the traditional notion of adolescent stress.
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49
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Shi YW, Fan BF, Xue L, Wen JL, Zhao H. Regulation of Fear Extinction in the Basolateral Amygdala by Dopamine D2 Receptors Accompanied by Altered GluR1, GluR1-Ser845 and NR2B Levels. Front Behav Neurosci 2017; 11:116. [PMID: 28676746 PMCID: PMC5476700 DOI: 10.3389/fnbeh.2017.00116] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/30/2017] [Indexed: 01/17/2023] Open
Abstract
The amygdala, a critical structure for both Pavlovian fear conditioning and fear extinction, receives sparse but comprehensive dopamine innervation and contains dopamine D1 and D2 receptors. Fear extinction, which involves learning to suppress the expression of a previously learned fear, appears to require the dopaminergic system. The specific roles of D2 receptors in mediating associative learning underlying fear extinction require further study. Intra-basolateral amygdala (BLA) infusions of a D2 receptor agonist, quinpirole, and a D2 receptor antagonist, sulpiride, prior to fear extinction and extinction retention were tested 24 h after fear extinction training for long-term memory (LTM). LTM was facilitated by quinpirole and attenuated by sulpiride. In addition, A-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor glutamate receptor 1 (GluR1) subunit, GluR1 phospho-Ser845, and N-methyl-D-aspartic acid receptor NR2B subunit levels in the BLA were generally increased by quinpirole and down-regulated by sulpiride. The present study suggests that activation of D2 receptors facilitates fear extinction and that blockade of D2 receptors impairs fear extinction, accompanied by changes in GluR1, GluR1-Ser845 and NR2B levels in the amygdala.
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Affiliation(s)
- Yan-Wei Shi
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China.,Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China.,Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China
| | - Bu-Fang Fan
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China
| | - Li Xue
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China.,Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China.,Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China
| | - Jia-Ling Wen
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China
| | - Hu Zhao
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China.,Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China.,Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-sen UniversityGuangzhou, China
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MicroRNA-Mediated Rescue of Fear Extinction Memory by miR-144-3p in Extinction-Impaired Mice. Biol Psychiatry 2017; 81:979-989. [PMID: 28104225 DOI: 10.1016/j.biopsych.2016.12.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/06/2016] [Accepted: 12/13/2016] [Indexed: 12/26/2022]
Abstract
BACKGROUND MicroRNA (miRNA)-mediated control of gene expression suggests that miRNAs are interesting targets and/or biomarkers in the treatment of anxiety- and trauma-related disorders, where often memory-associated gene expression is adversely affected. METHODS The role of miRNAs in the rescue of impaired fear extinction was assessed using the 129S1/SvlmJ (S1) mouse model of impaired fear extinction. miRNA microarray analysis, reverse transcription polymerase chain reaction, fluorescent in situ hybridization, lentiviral overexpression, and Luciferase reporter assays were used to gain insight into the mechanisms underlying miRNA-mediated normalization of deficient fear extinction. RESULTS Rescuing impaired fear extinction via dietary zinc restriction was associated with differential expression of miRNAs in the amygdala. One candidate, miR-144-3p, robustly expressed in the basolateral amygdala, showed specific extinction-induced, but not fear-induced, increased expression in both extinction-rescued S1 mice and extinction-intact C57BL/6 (BL6) mice. miR-144-3p upregulation and effects on subsequent behavioral adaption was assessed in S1 and BL6 mice. miR-144-3p overexpression in the basolateral amygdala rescued impaired fear extinction in S1 mice, led to enhanced fear extinction acquisition in BL6 mice, and furthermore protected against fear renewal in BL6 mice. miR-144-3p targets a number of genes implicated in the control of plasticity-associated signaling cascades, including Pten, Spred1, and Notch1. In functional interaction studies, we revealed that the miR-144-3p target, PTEN, colocalized with miR-144-3p in the basolateral amygdala and showed functional downregulation following successful fear extinction in S1 mice. CONCLUSIONS These findings identify a fundamental role of miR-144-3p in the rescue of impaired fear extinction and suggest this miRNA as a viable target in developing novel treatments for posttraumatic stress disorder and related disorders.
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