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Correia P, Demeter K, Varga J, Urbán E, Török B, Balázsfi D, Bakos N, Haller J, Zelena D. The effectiveness of extinction training in male rats: Temporal considerations and brain mechanisms. Behav Brain Res 2023; 441:114285. [PMID: 36610549 DOI: 10.1016/j.bbr.2023.114285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/12/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023]
Abstract
The extinction of conditioned fear is frequently used in laboratories as a model for human exposure therapy and is crucial for studies of posttraumatic stress disorder (PTSD). However, the efficacy of specific protocols can vary greatly, and the underlying brain mechanisms are not sufficiently clarified. To address this issue, variable starting time (one or twenty-eight days after fear conditioning) and extinction protocols were used, and the efficacy and durability of fear extinction were also studied. Changes in the behavior, stress hormone levels and neuronal activation patterns of stressed rats were analyzed. Conditioned fear was rapidly and efficiently extinguished by all the protocols investigated. However, when these extinction protocols were initiated one day after fear training, conditioned fear relapsed spontaneously four weeks later. In contrast, when extinction trials were started 28 days after conditioning, no relapse occurred. Hormone measurements taken by the end of extinction trials indicated that adrenocorticotropin, but not corticosterone responses reflected behavioral extinction without any sign of relapse. The last extinction training increased the activation of the medial prefrontal cortex and decreased the activation of the central and medial amygdala when extinction began one day after fear conditioning. By contrast, the activation of the basolateral amygdala and the entire hippocampus decreased by the last training session when extinction started 28 days after fear conditioning. Our findings show that extinction training can extinguish remote fear memories more effectively than recent ones, and that the brain mechanisms underlying remote and recent fear memory extinction differ. Laboratory models should also focus on a later time point to increase their translational value.
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Affiliation(s)
- Pedro Correia
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Budapest, Hungary; Janos Szentagothai School of Neurosciences, Semmelweis University, Budapest, Hungary; Institute of Physiology, Medical School, University of Pécs, Centre for Neuroscience, Szentágothai Research Centre, Pécs, Hungary
| | - Kornél Demeter
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Budapest, Hungary; Behavioral Studies Unit, Institute of Experimental Medicine, Budapest, Hungary
| | - János Varga
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Eszter Urbán
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Bibiána Török
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Budapest, Hungary; Janos Szentagothai School of Neurosciences, Semmelweis University, Budapest, Hungary; Institute of Physiology, Medical School, University of Pécs, Centre for Neuroscience, Szentágothai Research Centre, Pécs, Hungary
| | - Diána Balázsfi
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Nikoletta Bakos
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - József Haller
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Dóra Zelena
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Budapest, Hungary; Institute of Physiology, Medical School, University of Pécs, Centre for Neuroscience, Szentágothai Research Centre, Pécs, Hungary.
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Rescue of Vasopressin Synthesis in Magnocellular Neurons of the Supraoptic Nucleus Normalises Acute Stress-Induced Adrenocorticotropin Secretion and Unmasks an Effect on Social Behaviour in Male Vasopressin-Deficient Brattleboro Rats. Int J Mol Sci 2022; 23:ijms23031357. [PMID: 35163282 PMCID: PMC8836014 DOI: 10.3390/ijms23031357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/18/2022] [Accepted: 01/21/2022] [Indexed: 02/03/2023] Open
Abstract
The relevance of vasopressin (AVP) of magnocellular origin to the regulation of the endocrine stress axis and related behaviour is still under discussion. We aimed to obtain deeper insight into this process. To rescue magnocellular AVP synthesis, a vasopressin-containing adeno-associated virus vector (AVP-AAV) was injected into the supraoptic nucleus (SON) of AVP-deficient Brattleboro rats (di/di). We compared +/+, di/di, and AVP-AAV treated di/di male rats. The AVP-AAV treatment rescued the AVP synthesis in the SON both morphologically and functionally. It also rescued the peak of adrenocorticotropin release triggered by immune and metabolic challenges without affecting corticosterone levels. The elevated corticotropin-releasing hormone receptor 1 mRNA levels in the anterior pituitary of di/di-rats were diminished by the AVP-AAV-treatment. The altered c-Fos synthesis in di/di-rats in response to a metabolic stressor was normalised by AVP-AAV in both the SON and medial amygdala (MeA), but not in the central and basolateral amygdala or lateral hypothalamus. In vitro electrophysiological recordings showed an AVP-induced inhibition of MeA neurons that was prevented by picrotoxin administration, supporting the possible regulatory role of AVP originating in the SON. A memory deficit in the novel object recognition test seen in di/di animals remained unaffected by AVP-AAV treatment. Interestingly, although di/di rats show intact social investigation and aggression, the SON AVP-AAV treatment resulted in an alteration of these social behaviours. AVP released from the magnocellular SON neurons may stimulate adrenocorticotropin secretion in response to defined stressors and might participate in the fine-tuning of social behaviour with a possible contribution from the MeA.
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van Bodegom M, Homberg JR, Henckens MJAG. Modulation of the Hypothalamic-Pituitary-Adrenal Axis by Early Life Stress Exposure. Front Cell Neurosci 2017; 11:87. [PMID: 28469557 PMCID: PMC5395581 DOI: 10.3389/fncel.2017.00087] [Citation(s) in RCA: 310] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 03/13/2017] [Indexed: 12/20/2022] Open
Abstract
Exposure to stress during critical periods in development can have severe long-term consequences, increasing overall risk on psychopathology. One of the key stress response systems mediating these long-term effects of stress is the hypothalamic-pituitary-adrenal (HPA) axis; a cascade of central and peripheral events resulting in the release of corticosteroids from the adrenal glands. Activation of the HPA-axis affects brain functioning to ensure a proper behavioral response to the stressor, but stress-induced (mal)adaptation of the HPA-axis' functional maturation may provide a mechanistic basis for the altered stress susceptibility later in life. Development of the HPA-axis and the brain regions involved in its regulation starts prenatally and continues after birth, and is protected by several mechanisms preventing corticosteroid over-exposure to the maturing brain. Nevertheless, early life stress (ELS) exposure has been reported to have numerous consequences on HPA-axis function in adulthood, affecting both its basal and stress-induced activity. According to the match/mismatch theory, encountering ELS prepares an organism for similar ("matching") adversities during adulthood, while a mismatching environment results in an increased susceptibility to psychopathology, indicating that ELS can exert either beneficial or disadvantageous effects depending on the environmental context. Here, we review studies investigating the mechanistic underpinnings of the ELS-induced alterations in the structural and functional development of the HPA-axis and its key external regulators (amygdala, hippocampus, and prefrontal cortex). The effects of ELS appear highly dependent on the developmental time window affected, the sex of the offspring, and the developmental stage at which effects are assessed. Albeit by distinct mechanisms, ELS induced by prenatal stressors, maternal separation, or the limited nesting model inducing fragmented maternal care, typically results in HPA-axis hyper-reactivity in adulthood, as also found in major depression. This hyper-activity is related to increased corticotrophin-releasing hormone signaling and impaired glucocorticoid receptor-mediated negative feedback. In contrast, initial evidence for HPA-axis hypo-reactivity is observed for early social deprivation, potentially reflecting the abnormal HPA-axis function as observed in post-traumatic stress disorder, and future studies should investigate its neural/neuroendocrine foundation in further detail. Interestingly, experiencing additional (chronic) stress in adulthood seems to normalize these alterations in HPA-axis function, supporting the match/mismatch theory.
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Affiliation(s)
| | | | - Marloes J. A. G. Henckens
- Department of Cognitive Neuroscience, Centre for Neuroscience, Donders Institute for Brain, Cognition and BehaviourRadboudumc, Nijmegen, Netherlands
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Balázsfi D, Farkas L, Csikota P, Fodor A, Zsebők S, Haller J, Zelena D. Sex-dependent role of vesicular glutamate transporter 3 in stress-regulation and related anxiety phenotype during the early postnatal period. Stress 2016; 19:434-8. [PMID: 27442776 DOI: 10.1080/10253890.2016.1203413] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Stress and related disorders are in the focus of interest and glutamate is one of the most important neurotransmitters that can affect these processes. Glutamatergic neurons are characterized by vesicular glutamate transporters (VGluT1-3) among which vGluT3 is unique contributing to the non-canonical, neuromodulatory effect of glutamate. We aimed to study the role of vGluT3 in stress axis regulation and related anxiety during the early postnatal period using knockout (KO) mice with special focus on sex differences. Anxiety was explored on postnatal day (PND) 7-8 by maternal separation-induced ultrasonic vocalization (USV). Stress-hormone levels were detected 60 min after intraperitoneal lipopolysaccharide (LPS) injection 7 days later. Both genotypes gained weight, but on PND 14-15 KO mice pups had smaller body weight compared to wild type (WT). vGluT3 KO mice reacted to an immune stressor with enhanced adrenocorticotropin (ACTH) and corticosterone secretion compared to WT. Although there was a tendency for enhanced anxiety measured by more emitted USV, this did not reach the level of significance. The only sex-related effect was the enhanced corticosterone reactivity in male pups. For the HPA axis regulation in neonates vGluT3 expression seems to be dispensable under basal conditions, but is required for optimal response to immune stressors, most probably through an interaction with other neurotransmitters. Disturbance of the fine balance between these systems may result in a borderline enhanced anxiety-like behavior in vGluT3 KO pups.
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Affiliation(s)
- Diána Balázsfi
- a Hungarian Academy of Sciences, Institute of Experimental Medicine , Budapest , Hungary
- b János Szentágothai School of Neurosciences, Semmelweis University , Budapest , Hungary
| | - Lívia Farkas
- a Hungarian Academy of Sciences, Institute of Experimental Medicine , Budapest , Hungary
| | - Péter Csikota
- a Hungarian Academy of Sciences, Institute of Experimental Medicine , Budapest , Hungary
| | - Anna Fodor
- a Hungarian Academy of Sciences, Institute of Experimental Medicine , Budapest , Hungary
- b János Szentágothai School of Neurosciences, Semmelweis University , Budapest , Hungary
| | - Sándor Zsebők
- c Behaviuor Ecology Research Group, Department of Systematic Zoology and Ecology , Eötvös Loránd University , Budapest , Hungary
| | - József Haller
- a Hungarian Academy of Sciences, Institute of Experimental Medicine , Budapest , Hungary
| | - Dóra Zelena
- a Hungarian Academy of Sciences, Institute of Experimental Medicine , Budapest , Hungary
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Fodor A, Kovács KB, Balázsfi D, Klausz B, Pintér O, Demeter K, Daviu N, Rabasa C, Rotllant D, Nadal R, Zelena D. Depressive- and anxiety-like behaviors and stress-related neuronal activation in vasopressin-deficient female Brattleboro rats. Physiol Behav 2016; 158:100-11. [DOI: 10.1016/j.physbeh.2016.02.041] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 02/24/2016] [Accepted: 02/27/2016] [Indexed: 12/17/2022]
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Zelena D. The janus face of stress on reproduction: from health to disease. Int J Endocrinol 2015; 2015:458129. [PMID: 25945091 PMCID: PMC4405284 DOI: 10.1155/2015/458129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/17/2015] [Accepted: 03/20/2015] [Indexed: 12/16/2022] Open
Abstract
Parenthood is a fundamental feature of all known life. However, infertility has been recognized as a public health issue worldwide. But even when the offspring are conceived, in utero problems can lead to immediate (abortion), early (birth), and late (adulthood) consequences. One of the most studied factors is stress. However, stress response is, per se, of adaptive nature allowing the organism to cope with challenges. Stressors lead to deterioration if one is faced with too long lasting, too many, and seemingly unsolvable situations. In stress adaptation the hypothalamus-pituitary-adrenocortical axis and the resulting glucocorticoid elevation are one of the most important mechanisms. At cellular level stress can be defined as an unbalance between production of free radicals and antioxidant defenses. Oxidative stress is widely accepted as an important pathogenic mechanism in different diseases including infertility. On the other hand, the goal of free radical production is to protect the cells from infectious entities. This review aims to summarize the negative and positive influence of stress on reproduction as a process leading to healthy progeny. Special emphasis was given to the balance at the level of the organism and cells.
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Affiliation(s)
- Dóra Zelena
- Hungarian Academy of Sciences, Institute of Experimental Medicine, Szigony 43, Budapest 1083, Hungary
- *Dóra Zelena:
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