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Zaman A, Özçelik H, Yücel E, Su Akkan S, Onsinejad T, Mert Yüksel S, Bülbül M. Effect of sex on chronic stress induced alterations in hindbrain catecholaminergic system and autonomic dysfunction resulting in gastrointestinal dysmotility. Brain Res 2024; 1842:149112. [PMID: 38969083 DOI: 10.1016/j.brainres.2024.149112] [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: 08/21/2023] [Revised: 06/29/2024] [Accepted: 07/02/2024] [Indexed: 07/07/2024]
Abstract
It has been reported that the clinical symptoms of functional dyspepsia (FD) exacerbate upon stress while the gender-related factors have been incompletely understood. This study aims to investigate the role of sex in chronic heterotypic stress (CHS)-induced autonomic and gastric motor dysfunction. For CHS, the rats were exposed to the combination of different stressors for 7 consecutive days. Subsequently, electrocardiography was recorded in anesthetized rats to evaluate heart rate variability (HRV) for the determination of autonomic outflow and sympathovagal balance. Solid gastric emptying (GE) was measured in control and CHS-loaded male and female rats. The immunoreactivities of catecholaminergic cell marker tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), corticotropin releasing factor (CRF), and estrogen receptor (ER-α/β) were evaluated in medullary and pontine brainstem sections by immunohistochemistry. Compared with the controls, CHS significantly delayed GE in males but not in females. There was no significant sex-related difference in parasympathetic indicator HF under either control or CHS conditions. Sympathetic indicator LF was significantly higher in control females compared to the males. The higher sympathetic output in females was found to be attenuated upon CHS; in contrast, the elevated sympathetic output was detected in CHS-loaded males. No sex- or stress-related effect was observed on ChAT immunoreactivity in the dorsal motor nucleus of N.vagus (DMV). In males, greater number of TH-ir cells was observed in the caudal locus coeruleus (LC), while they were more densely detected in the rostral LC of females. Regardless of sex, CHS elevated immunoreactivity of TH throughout the LC. Under basal conditions, greater number of TH-ir cells was detected in the rostral ventrolateral medulla (RVLM) of females. In contrast, CHS remarkably increased the number of TH-ir cells in the RVLM of males which was found to be decreased in females. There was no sex-related alteration in TH immunoreactivity in the nucleus tractus solitarius (NTS) of control rats, while CHS affected both sexes in a similar manner. Compared with females, CRF immunoreactivity was prominently observed in control males, while both of which were stimulated by CHS. ER-α/β was found to be co-expressed with TH in the NTS and LC which exhibit no alteration related to either sex or stress status. These results indicate a sexual dimorphism in the catecholaminergic and the CRF system in brainstem which might be involved in the CHS-induced autonomic and visceral dysfunction occurred in males.
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Affiliation(s)
- Amirali Zaman
- Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | | | - Elif Yücel
- Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | - Simla Su Akkan
- Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | - Tanaz Onsinejad
- Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | - Sadettin Mert Yüksel
- Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | - Mehmet Bülbül
- Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey.
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Pace SA, Myers B. Hindbrain Adrenergic/Noradrenergic Control of Integrated Endocrine and Autonomic Stress Responses. Endocrinology 2023; 165:bqad178. [PMID: 38015813 DOI: 10.1210/endocr/bqad178] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/07/2023] [Accepted: 11/27/2023] [Indexed: 11/30/2023]
Abstract
Hindbrain adrenergic/noradrenergic nuclei facilitate endocrine and autonomic responses to physical and psychological challenges. Neurons that synthesize adrenaline and noradrenaline target hypothalamic structures to modulate endocrine responses while descending spinal projections regulate sympathetic function. Furthermore, these neurons respond to diverse stress-related metabolic, autonomic, and psychosocial challenges. Accordingly, adrenergic and noradrenergic nuclei are integrative hubs that promote physiological adaptation to maintain homeostasis. However, the precise mechanisms through which adrenaline- and noradrenaline-synthesizing neurons sense interoceptive and exteroceptive cues to coordinate physiological responses have yet to be fully elucidated. Additionally, the regulatory role of these cells in the context of chronic stress has received limited attention. This mini-review consolidates reports from preclinical rodent studies on the organization and function of brainstem adrenaline and noradrenaline cells to provide a framework for how these nuclei coordinate endocrine and autonomic physiology. This includes identification of hindbrain adrenaline- and noradrenaline-producing cell groups and their role in stress responding through neurosecretory and autonomic engagement. Although temporally and mechanistically distinct, the endocrine and autonomic stress axes are complementary and interconnected. Therefore, the interplay between brainstem adrenergic/noradrenergic nuclei and peripheral physiological systems is necessary for integrated stress responses and organismal survival.
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Affiliation(s)
- Sebastian A Pace
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Brent Myers
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
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Busceti CL, Bucci D, Scioli M, Di Pietro P, Nicoletti F, Puglisi-Allegra S, Ferrucci M, Fornai F. Chronic treatment with corticosterone increases the number of tyrosine hydroxylase-expressing cells within specific nuclei of the brainstem reticular formation. Front Neuroanat 2022; 16:976714. [DOI: 10.3389/fnana.2022.976714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 10/06/2022] [Indexed: 11/13/2022] Open
Abstract
Cushing's syndrome is due to increased glucocorticoid levels in the body, and it is characterized by several clinical alterations which concern both vegetative and behavioral functions. The anatomical correlates of these effects remain largely unknown. Apart from peripheral effects induced by corticosteroids as counter-insular hormones, only a few reports are available concerning the neurobiology of glucocorticoid-induced vegetative and behavioral alterations. In the present study, C57 Black mice were administered daily a chronic treatment with corticosterone in drinking water. This treatment produces a significant and selective increase of TH-positive neurons within two nuclei placed in the lateral column of the brainstem reticular formation. These alterations significantly correlate with selective domains of Cushing's syndrome. Specifically, the increase of TH neurons within area postrema significantly correlates with the development of glucose intolerance, which is in line with the selective control by area postrema of vagal neurons innervating the pancreas. The other nucleus corresponds to the retrorubral field, which is involved in the behavioral activity. In detail, the retrorubral field is likely to modulate anxiety and mood disorders, which frequently occur following chronic exposure to glucocorticoids. To our knowledge, this is the first study that provides the neuroanatomical basis underlying specific symptoms occurring in Cushing's syndrome.
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Fulenwider HD, Caruso MA, Ryabinin AE. Manifestations of domination: Assessments of social dominance in rodents. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12731. [PMID: 33769667 PMCID: PMC8464621 DOI: 10.1111/gbb.12731] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/31/2021] [Accepted: 03/22/2021] [Indexed: 01/01/2023]
Abstract
Social hierarchies are ubiquitous features of virtually all animal groups. The varying social ranks of members within these groups have profound effects on both physical and emotional health, with lower-ranked individuals typically being the most adversely affected by their respective ranks. Thus, reliable measures of social dominance in preclinical rodent models are necessary to better understand the effects of an individual's social rank on other behaviors and physiological processes. In this review, we outline the primary methodologies used to assess social dominance in various rodent species: those that are based on analyses of agonistic behaviors, and those that are based on resource competition. In synthesizing this review, we conclude that assays based on resource competition may be better suited to characterize social dominance in a wider variety of rodent species and strains, and in both males and females. Lastly, albeit expectedly, we demonstrate that similarly to many other areas of preclinical research, studies incorporating female subjects are lacking in comparison to those using males. These findings emphasize the need for an increased number of studies assessing social dominance in females to form a more comprehensive understanding of this behavioral phenomenon.
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Affiliation(s)
- Hannah D. Fulenwider
- Department of Behavioral NeuroscienceOregon Health & Science UniversityPortlandORUSA
| | - Maya A. Caruso
- Department of Behavioral NeuroscienceOregon Health & Science UniversityPortlandORUSA
| | - Andrey E. Ryabinin
- Department of Behavioral NeuroscienceOregon Health & Science UniversityPortlandORUSA
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Understanding stress: Insights from rodent models. CURRENT RESEARCH IN NEUROBIOLOGY 2021; 2:100013. [PMID: 36246514 PMCID: PMC9559100 DOI: 10.1016/j.crneur.2021.100013] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/30/2021] [Accepted: 05/08/2021] [Indexed: 02/01/2023] Open
Abstract
Through incorporating both physical and psychological forms of stressors, a variety of rodent models have provided important insights into the understanding of stress physiology. Rodent models also have provided significant information with regards to the mechanistic basis of the pathophysiology of stress-related disorders such as anxiety disorders, depressive illnesses, cognitive impairment and post-traumatic stress disorder. Additionally, rodent models of stress have served as valuable tools in the area of drug screening and drug development for treatment of stress-induced conditions. Although rodent models do not accurately reproduce the biochemical or physiological parameters of stress response and cannot fully mimic the natural progression of human disorders, yet, animal research has provided answers to many important scientific questions. In this review article, important studies utilizing a variety of stress models are described in terms of their design and apparatus, with specific focus on their capabilities to generate reliable behavioral and biochemical read-out. The review focusses on the utility of rodent models by discussing examples in the literature that offer important mechanistic insights into physiologically relevant questions. The review highlights the utility of rodent models of stress as important tools for advancing the mission of scientific research and inquiry. Stressful life events may lead to the onset of severe psychopathologies in humans. Rodents may model many features of stress exposure in human populations. Induction of stress via pharmacological and psychological manipulations alter rodent behavior. Mechanistic rodent studies reveal key molecular targets critical for new therapeutic targets.
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Fan Y, Chen P, Raza MU, Szebeni A, Szebeni K, Ordway GA, Stockmeier CA, Zhu MY. Altered Expression of Phox2 Transcription Factors in the Locus Coeruleus in Major Depressive Disorder Mimicked by Chronic Stress and Corticosterone Treatment In Vivo and In Vitro. Neuroscience 2018; 393:123-137. [PMID: 30315878 DOI: 10.1016/j.neuroscience.2018.09.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/21/2018] [Accepted: 09/26/2018] [Indexed: 12/16/2022]
Abstract
Phox2a and Phox2b are two homeodomain transcription factors playing a pivotal role in the development of noradrenergic neurons during the embryonic period. However, their expression and function in adulthood remain to be elucidated. Using human postmortem brain tissues, rat stress models and cultured cells, this study aimed to examine the alteration of Phox2a and Phox2b expression. The results show that Phox2a and Phox2b are normally expressed in the human locus coeruleus (LC) in adulthood. Furthermore, the levels of Phox2a protein and mRNA and protein levels of Phox2b were significantly elevated in the LC of brain donors that suffered from the major depressive disorder, as compared to age-matched and psychiatrically normal control donors. Fischer 344 rats subjected to chronic social defeat showed higher mRNA and protein levels of Phox2a and Phox2b in the LC, as compared to non-stressed control rats. In rats chronically administered oral corticosterone, mRNA and protein levels of Phox2b, but not Phox2a, in the LC were significantly increased. In addition, the corticosterone-induced increase in Phox2b protein was reversed by simultaneous treatment with either mifepristone or spironolactone. Exposing SH-SY5Y cells to corticosterone significantly increased expression of Phox2a and Phox2b, which was blocked by corticosteroid receptor antagonists. Taken together, these experiments reveal that Phox2 genes are expressed throughout the lifetime in the LC of humans and Fischer 344 rats. Alterations in their expression may play a role in major depressive disorder and possibly other stress-related disorders through their modulatory effects on the noradrenergic phenotype.
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Affiliation(s)
- Yan Fan
- Department of Biochemistry, Nantong University College of Medicine, Nantong, China
| | - Ping Chen
- School of Life Science and Technology, Tongji University, Shanghai, China
| | - Muhammad U Raza
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Attila Szebeni
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Katalin Szebeni
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Gregory A Ordway
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Craig A Stockmeier
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA
| | - Meng-Yang Zhu
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA.
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7
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Sominsky L, Ong LK, Ziko I, Dickson PW, Spencer SJ. Neonatal overfeeding increases capacity for catecholamine biosynthesis from the adrenal gland acutely and long-term in the male rat. Mol Cell Endocrinol 2018; 470:295-303. [PMID: 29183807 DOI: 10.1016/j.mce.2017.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 11/15/2017] [Accepted: 11/15/2017] [Indexed: 12/22/2022]
Abstract
A poor nutritional environment during early development has long been known to increase disease susceptibility later in life. We have previously shown that rats that are overfed as neonates (i.e. suckled in small litters (4 pups) relative to control conditions (12 pups)) show dysregulated hypothalamic-pituitary-adrenal axis responses to immune stress in adulthood, particularly due to an altered capacity of the adrenal to respond to an immune challenge. Here we hypothesised that neonatal overfeeding similarly affects the sympathomedullary system, testing this by investigating the biochemical function of tyrosine hydroxylase (TH), the first rate-limiting enzyme in the catecholamine synthesis. We also examined changes in adrenal expression of the leptin receptor and in mitogen-activated protein kinase (MAPK) signalling. During the neonatal period, we saw age-dependent changes in TH activity and phosphorylation, with neonatal overfeeding stimulating increased adrenal TH specific activity at postnatal days 7 and 14, along with a compensatory reduction in total TH protein levels. This increased TH activity was maintained into adulthood where neonatally overfed rats exhibited increased adrenal responsiveness 30 min after an immune challenge with lipopolysaccharide, evident in a concomitant increase in TH protein levels and specific activity. Neonatal overfeeding significantly reduced the expression of the leptin receptor in neonatal adrenals at postnatal day 7 and in adult adrenals, but did not affect MAPK signalling. These data suggest neonatal overfeeding alters the capacity of the adrenal to synthesise catecholamines, both acutely and long term, and these effects may be independent of leptin signalling.
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Affiliation(s)
- Luba Sominsky
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic., Australia.
| | - Lin Kooi Ong
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia; Hunter Medical Research Institute, NSW, Australia
| | - Ilvana Ziko
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic., Australia
| | - Phillip W Dickson
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia; Hunter Medical Research Institute, NSW, Australia
| | - Sarah J Spencer
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic., Australia
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8
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Herman JP. Regulation of Hypothalamo-Pituitary-Adrenocortical Responses to Stressors by the Nucleus of the Solitary Tract/Dorsal Vagal Complex. Cell Mol Neurobiol 2017; 38:25-35. [PMID: 28895001 DOI: 10.1007/s10571-017-0543-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/24/2017] [Indexed: 01/04/2023]
Abstract
Hindbrain neurons in the nucleus of the solitary tract (NTS) are critical for regulation of hypothalamo-pituitary-adrenocortical (HPA) responses to stress. It is well known that noradrenergic (as well as adrenergic) neurons in the NTS send direct projections to hypophysiotropic corticotropin-releasing hormone (CRH) neurons and control activation of HPA axis responses to acute systemic (but not psychogenic) stressors. Norepinephrine (NE) signaling via alpha1 receptors is primarily excitatory, working either directly on CRH neurons or through presynaptic activation of glutamate release. However, there is also evidence for NE inhibition of CRH neurons (possibly via beta receptors), an effect that may occur at higher levels of stimulation, suggesting that NE effects on the HPA axis may be context-dependent. Lesions of ascending NE inputs to the paraventricular nucleus attenuate stress-induced ACTH but not corticosterone release after chronic stress, indicating reduction in central HPA drive and increased adrenal sensitivity. Non-catecholaminergic NTS glucagon-like peptide 1/glutamate neurons play a broader role in stress regulation, being important in HPA activation to both systemic and psychogenic stressors as well as HPA axis sensitization under conditions of chronic stress. Overall, the data highlight the importance of the NTS as a key regulatory node for coordination of acute and chronic stress.
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Affiliation(s)
- James P Herman
- Stress Neurobiology Laboratory, Department of Psychiatry and Behavioral Neuroscience, UC Neurobiology Research Center, University of Cincinnati, 2170 East Galbraith Road, Cincinnati, OH, 45237-0506, USA.
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9
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Herman JP, Tamashiro KL. The visible burrow system: A view from across the hall. Physiol Behav 2017; 178:103-109. [PMID: 28089702 DOI: 10.1016/j.physbeh.2017.01.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 01/11/2017] [Indexed: 10/20/2022]
Abstract
The visible burrow system (VBS) is an ethologically relevant social stress model that creates a distinct dominance hierarchy in rats. Randall Sakai's laboratory performed an impressive series of studies documenting the very different impact of VBS exposure on the brain and behavior of dominants (DOM) and subordinates (SUBs). Hierarchy formation causes pronounced changes in metabolism in SUBs relative to both DOMs and unstressed controls, resulting in marked weight loss and metabolic imbalance. Stress testing revealed multiple phenotypes in the VBS, including DOMs, stress-responsive SUBs and stress-non-responsive SUBs. Stress-responsive SUBs have adrenal hypertrophy and elevated baseline corticosterone, consistent with prolonged HPA axis activation; however, peak acute stress responses are not sensitized. In contrast, stress non-responsive individuals do not mount a response to an acute stress, suggesting HPA axis hypofunction. In brain, SUBs exhibit a pattern of gene regulation consistent with impaired stress inhibition (e.g., hippocampal adrenocorticosteroid receptor down-regulation and dendritic retraction) and drive of stress pathways (e.g., increased locus coeruleus tyrosine hydroxylase expression). The non-responsive phenotype is distinguished by down-regulation of paraventricular nucleus corticotropin releasing hormone expression and enhanced neuropeptide Y expression in amygdala. The brain 'signature' created by VBS hierarchy formation differed substantially from that of another well-studied chronic stress model (chronic variable stress). Thus, the impact of VBS is mediated by neurocircuit mechanisms at least in part distinct that of other chronic stress modalities, and suggests that the nature of the stressor may be an essential consideration in development of treatment strategies for stress-related diseases.
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Affiliation(s)
- James P Herman
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH 45237, United States.
| | - Kellie L Tamashiro
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States
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McEwen BS, McKittrick CR, Tamashiro KLK, Sakai RR. The brain on stress: Insight from studies using the Visible Burrow System. Physiol Behav 2016; 146:47-56. [PMID: 26066722 DOI: 10.1016/j.physbeh.2015.04.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 04/04/2015] [Accepted: 04/07/2015] [Indexed: 11/26/2022]
Abstract
The discovery of adrenal steroid receptors outside of the hypothalamus in the hippocampus and other forebrain regions catalyzed research on the effects of stress upon cognitive function, emotions and self-regulatory behaviors as well as the molecular, cellular and neuroanatomical mechanisms underlying acute and chronic stress effects on the brain. Indeed, this work has shown that the brain is a plastic and vulnerable organ in the face of acute and chronic stress. The insight that Bob and Caroline Blanchard had in developing and interpreting findings using the Visible Burrow System model made an enormous contribution to the current view that the human brain is very sensitive to the social environment and to agonistic interactions between individuals. Their collaboration with Sakai and McEwen at The Rockefeller University extended application of the Visible Burrow System model to demonstrate that it also was a unique and highly relevant neuroethological model with which to study stress and adaptation to stressors. Those studies focused on the brain and systemic organ responses to stress and, in turn, described that the brain is also very responsive to changes in systemic physiology.
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Robertson JM, Prince MA, Achua JK, Carpenter RE, Arendt DH, Smith JP, Summers TL, Summers TR, Summers CH. Nuance and behavioral cogency: How the Visible Burrow System inspired the Stress-Alternatives Model and conceptualization of the continuum of anxiety. Physiol Behav 2016; 146:86-97. [PMID: 26066728 DOI: 10.1016/j.physbeh.2015.03.036] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 12/20/2022]
Abstract
By creating the Visible Burrow System (VBS) Bob Blanchard found a way to study the interaction of genetics, physiology, environment, and adaptive significance in a model with broad validity. The VBS changed the way we think about anxiety and affective disorders by allowing the mechanisms which control them to be observed in a dynamic setting. Critically, Blanchard used the VBS and other models to show how behavioral systems like defense are dependent upon context and behavioral elements unique to the individual. Inspired by the VBS, we developed a Stress Alternatives Model (SAM) to further explore the multifaceted dynamics of the stress response with a dichotomous choice condition. Like the VBS, the SAM is a naturalistic model built upon risk assessment and defensive behavior, but with a choice of response: escape or submission to a large conspecific aggressor. The anxiety of novelty during the first escape must be weighed against fear of the aggressor, and a decision must be made. Both outcomes are adaptively significant, evidenced by a 50/50 split in outcome across several study systems. By manipulating the variables of the SAM, we show that a gradient of anxiety exists that spans the contextual settings of escaping an open field, escaping from aggression, and submitting to aggression. These findings correspond with increasing levels of corticosterone and increasing levels of NPS and BDNF in the central amygdala as the context changes.Whereas some anxiolytics were able to reduce the latency to escape for some animals, only with the potent anxiolytic drug antalarmin (CRF1R-blocker) and the anxiogenic drug yohimbine (α2 antagonist) were we able to reverse the outcome for a substantial proportion of individuals. Our findings promote a novel method for modeling anxiety, offering a distinction between low-and-high levels, and accounting for individual variability. The translational value of the VBS is immeasurable, and it guided us and many other researchers to seek potential clinical solutions through a deeper understanding of regional neurochemistry and gene expression in concert with an ecological behavioral model.
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Decreased Interleukin-4 Release from the Neurons of the Locus Coeruleus in Response to Immobilization Stress. Mediators Inflamm 2016; 2016:3501905. [PMID: 26903707 PMCID: PMC4745346 DOI: 10.1155/2016/3501905] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 07/02/2015] [Accepted: 12/17/2015] [Indexed: 11/18/2022] Open
Abstract
It has been demonstrated that immobilization (IMO) stress affects neuroimmune systems followed by alterations of physiology and behavior. Interleukin-4 (IL-4), an anti-inflammatory cytokine, is known to regulate inflammation caused by immune challenge but the effect of IMO on modulation of IL-4 expression in the brain has not been assessed yet. Here, it was demonstrated that IL-4 was produced by noradrenergic neurons in the locus coeruleus (LC) of the brain and release of IL-4 was reduced in response to IMO. It was observed that IMO groups were more anxious than nontreated groups. Acute IMO (2 h/day, once) stimulated secretion of plasma corticosterone and tyrosine hydroxylase (TH) in the LC whereas these increments were diminished in exposure to chronic stress (2 h/day, 21 consecutive days). Glucocorticoid receptor (GR), TH, and IL-4-expressing cells were localized in identical neurons of the LC, indicating that hypothalamic-pituitary-adrenal- (HPA-) axis and sympathetic-adrenal-medullary- (SAM-) axis might be involved in IL-4 secretion in the stress response. Accordingly, it was concluded that stress-induced decline of IL-4 concentration from LC neurons may be related to anxiety-like behavior and an inverse relationship exists between IL-4 secretion and HPA/SAM-axes activation.
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Mravec B, Vargovic P, Filipcik P, Novak M, Kvetnansky R. Effect of a single and repeated stress exposure on gene expression of catecholamine biosynthetic enzymes in brainstem catecholaminergic cell groups in rats. Eur J Neurosci 2015; 42:1872-86. [PMID: 25994480 DOI: 10.1111/ejn.12955] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 05/14/2015] [Accepted: 05/15/2015] [Indexed: 12/14/2022]
Abstract
Brainstem catecholaminergic neurons significantly participate in the regulation of neuroendocrine system activity, particularly during stressful conditions. However, so far the precise quantitative characterisation of basal and stress-induced changes in gene expression and protein levels of catecholaminergic biosynthetic enzymes in these neurons has been missing. Using a quantitative reverse transcription-polymerase chain reaction method, we investigated gene expression of catecholamine biosynthetic enzymes in brainstem noradrenergic and adrenergic cell groups in rats under resting conditions as well as in acutely and repeatedly stressed animals. For the first time, we described quantitative differences in basal levels of catecholamine biosynthetic enzyme mRNA in brainstem catecholaminergic ascending and descending projecting cell groups. Moreover, we found and defined some differences among catecholaminergic cell groups in the time-course of mRNA levels of catecholaminergic enzymes following a single and especially repeated immobilisation stress. The data obtained support the assumption that brainstem catecholaminergic cell groups represent a functionally differentiated system, which is highly (but specifically) activated in rats exposed to stress. Therefore, potential interventions for the treatment of stress-related diseases need to affect the activity of brainstem catecholaminergic neurons not uniformly but with some degree of selectivity.
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Affiliation(s)
- Boris Mravec
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska 3, 833 06, Bratislava, Slovakia.,Institute of Physiology, Faculty of Medicine, Comenius University in Bratislava, Slovakia
| | - Peter Vargovic
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska 3, 833 06, Bratislava, Slovakia
| | - Peter Filipcik
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Michal Novak
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Richard Kvetnansky
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska 3, 833 06, Bratislava, Slovakia
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14
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Spasojevic N, Jovanovic P, Stefanovic B, Dronjak S. Influence of individual housing in the adult rats on catecholamine synthesis and storage in the right and left medial prefrontal cortex. NEUROCHEM J+ 2014. [DOI: 10.1134/s1819712414040084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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Flak JN, Myers B, Solomon MB, McKlveen JM, Krause EG, Herman JP. Role of paraventricular nucleus-projecting norepinephrine/epinephrine neurons in acute and chronic stress. Eur J Neurosci 2014; 39:1903-11. [PMID: 24766138 DOI: 10.1111/ejn.12587] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 03/07/2014] [Accepted: 03/10/2014] [Indexed: 01/06/2023]
Abstract
Chronic variable stress (CVS) exposure modifies the paraventricular nucleus of the hypothalamus (PVN) in a manner consistent with enhanced central drive of the hypothalamo-pituitary-adrenocortical (HPA) axis. As previous reports suggest that post-stress enhancement of norepinephrine (NE) action contributes to chronic stress regulation at the level of the PVN, we hypothesised that PVN-projecting NE neurons were necessary for the stress facilitatory effects of CVS. Following intra-PVN injection of saporin toxin conjugated to a dopamine beta-hydroxylase (DBH) antibody (DSAP), in rats PVN DBH immunoreactivity was almost completely eliminated, but immunoreactive afferents to other key regions involved in stress integration were spared (e.g. DBH fiber densities were unaffected in the central nucleus of the amygdala). Reductions in DBH-positive fiber density were associated with reduced numbers of DBH-immunoreactive neurons in the nucleus of the solitary tract and locus coeruleus. Following 2 weeks of CVS, DSAP injection did not alter stress-induced adrenal hypertrophy or attenuation of body weight gain, indicating that PVN-projecting NE [and epinephrine (E)] neurons are not essential for these physiological effects of chronic stress. In response to acute restraint stress, PVN-targeted DSAP injection attenuated peak adrenocorticotrophic hormone (ACTH) and corticosterone in controls, but only attenuated peak ACTH in CVS animals, suggesting that enhanced adrenal sensitivity compensated for reduced excitatory drive of the PVN. Our data suggest that PVN-projecting NE/E neurons contribute to the generation of acute stress responses, and are required for HPA axis drive (ACTH release) during chronic stress. However, loss of NE/E drive at the PVN appears to be buffered by compensation at the level of the adrenal.
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Affiliation(s)
- Jonathan N Flak
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Psychiatry North, Building E, 2nd Floor, 2170 East Galbraith Road, Cincinnati, OH, 45237-0506, USA; Neuroscience Program, University of Cincinnati, Cincinnati, OH, USA
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FAN YAN, CHEN PING, LI YING, ZHU MENGYANG. Effects of chronic social defeat on expression of dopamine β-hydroxylase in rat brains. Synapse 2013; 67:300-12. [PMID: 23389997 PMCID: PMC9338777 DOI: 10.1002/syn.21641] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 01/29/2013] [Indexed: 12/23/2023]
Abstract
It is documented that stress activates the locus coeruleus-norepinephrine system. However, there are far few reports regarding effects of stress on the expression of dopamine β-hydroxylase, a hallmark enzyme of the noradrenergic neuron. In the present study, adult Fischer 344 rats were subjected to chronic social defeat for 4 weeks. Dopamine β-hydroxylase expressional levels in the locus coeruleus and its terminal regions were measured by in situ hybridization and western blotting. The results showed that immediately following chronic social defeat there are significantly increased mRNA and protein levels of dopamine β-hydroxylase in the locus coeruleus, and dopamine β-hydroxylase protein levels in the hippocampus, frontal cortex and amygdala, compared with those in the control. This chronic social defeat-induced upregulation of dopamine β-hydroxylase was completely abolished by adrenalectomy, and/or by treatment with corticosteroid receptor antagonists, mifepristone and spironolactone, either alone or in combination. Furthermore, treatment with desipramine, an antidepressant with specific inhibitory effects on norepinephrine transport, prevented an increased dopamine β-hydroxylase expression by chronic social defeat in the locus coeruleus and its main terminal regions such as the hippocampus, frontal cortex and amygdala. However, treatment with fluoxetine, an antidepressant with specific inhibition for serotonin transport, only selectively blocked increased dopamine β-hydroxylase protein levels in the hippocampus caused by CSD. The present findings indicate that chronic social defeat activates the locus coeruleus-norepinephrine system by upregulating the expression of dopamine β-hydroxylase, which may increase norepinephrine synthesis. This chronic social defeat induced upregulation of DBH expression was mediated through corticosterone and corticosteroid receptors, with possible interference from antidepressants.
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Affiliation(s)
- YAN FAN
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - PING CHEN
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
- The Laboratory of Developmental Epigenetics, School of Life Science and Technology, Tongji University, Shanghai, China
| | - YING LI
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - MENG-YANG ZHU
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
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George SA, Knox D, Curtis AL, Aldridge JW, Valentino RJ, Liberzon I. Altered locus coeruleus-norepinephrine function following single prolonged stress. Eur J Neurosci 2012; 37:901-9. [PMID: 23279008 DOI: 10.1111/ejn.12095] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 11/14/2012] [Accepted: 11/16/2012] [Indexed: 01/06/2023]
Abstract
Data from preclinical and clinical studies have implicated the norepinephrine system in the development and maintenance of post-traumatic stress disorder. The primary source of norepinephrine in the forebrain is the locus coeruleus (LC); however, LC activity cannot be directly measured in humans, and previous research has often relied upon peripheral measures of norepinephrine to infer changes in central LC-norepinephrine function. To directly assess LC-norepinephrine function, we measured single-unit activity of LC neurons in a validated rat model of post-traumatic stress disorder - single prolonged stress (SPS). We also examined tyrosine hydroxylase mRNA levels in the LC of SPS and control rats as an index of norepinephrine utilisation. For electrophysiological recordings, 92 LC neurons were identified from 19 rats (SPS, 12; control, 7), and spontaneous and evoked responses to a noxious event (paw compression) were recorded. Baseline and restraint stress-evoked tyrosine hydroxylase mRNA expression levels were measured in SPS and control rats (n = 16 per group) in a separate experiment. SPS rats showed lower spontaneous activity but higher evoked responses, leading to an enhanced signal-to-noise ratio of LC neurons, accompanied by impaired recovery from post-stimulus inhibition. In concert, tyrosine hydroxylase mRNA expression in the LC of SPS rats tended to be lower at baseline, but was exaggerated following restraint stress. These data demonstrate persistent changes in LC function following stress/trauma in a rat model of post-traumatic stress, as measured by differences in both the electrophysiological properties of LC neurons and tyrosine hydroxylase mRNA transcription.
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Affiliation(s)
- Sophie A George
- University of Michigan, Rachel Upjohn Building, 4250 Plymouth Rd (Box 5765), Ann Arbor, MI 48109-2700, USA.
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Michopoulos V, Higgins M, Toufexis D, Wilson ME. Social subordination produces distinct stress-related phenotypes in female rhesus monkeys. Psychoneuroendocrinology 2012; 37:1071-85. [PMID: 22244748 PMCID: PMC3358530 DOI: 10.1016/j.psyneuen.2011.12.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 11/30/2011] [Accepted: 12/02/2011] [Indexed: 12/12/2022]
Abstract
Social subordination in female macaques is imposed by harassment and the threat of aggression and produces reduced control over one's social and physical environment and a dysregulation of the limbic-hypothalamic-pituitary-adrenal axis resembling that observed in people suffering from psychopathologies. These effects support the contention that this particular animal model is an ethologically relevant paradigm in which to investigate the etiology of stress-induced psychological illness related to women. Here, we sought to expand this model by performing a discriminate analysis (DA) on 33 variables within three domains; behavioral, metabolic/anthropomorphic, and neuroendocrine, collected from socially housed female rhesus monkeys in order to assess whether exposure to social subordination produces a distinct phenotype. A receiver operating characteristic (ROC) curve was also calculated to determine each domain's classification accuracy. DA found significant markers within each domain that differentiated dominant and subordinate females. Subordinate females received more aggression, showed more submissive behavior, and received less of affiliation from others than did dominant females. Metabolic differences included increased leptin, and reduced adiponectin in dominant compared to subordinate females. Dominant females exhibited increased sensitivity to hormonal stimulation with higher serum LH in response to estradiol, cortisol in response to ACTH, and increased glucocorticoid negative feedback. Serum oxytocin, CSF DOPAC and serum PACAP were all significantly higher in dominant females. ROC curve analysis accurately predicted social status in all three domains. Results suggest that socially house rhesus monkeys represent a cogent animal model in which to study the physiology and behavioral consequences of chronic psychosocial stress in humans.
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Affiliation(s)
- Vasiliki Michopoulos
- Division of Developmental & Cognitive Neuroscience, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA.
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Ong LK, Sominsky L, Dickson PW, Hodgson DM, Dunkley PR. The Sustained Phase of Tyrosine Hydroxylase Activation In vivo. Neurochem Res 2012; 37:1938-43. [DOI: 10.1007/s11064-012-0812-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 04/26/2012] [Accepted: 05/26/2012] [Indexed: 11/29/2022]
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Pavlidis M, Sundvik M, Chen YC, Panula P. Adaptive changes in zebrafish brain in dominant–subordinate behavioral context. Behav Brain Res 2011; 225:529-37. [DOI: 10.1016/j.bbr.2011.08.022] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 08/11/2011] [Accepted: 08/13/2011] [Indexed: 01/19/2023]
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21
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Miczek KA, Nikulina EM, Takahashi A, Covington HE, Yap JJ, Boyson CO, Shimamoto A, de Almeida RMM. Gene expression in aminergic and peptidergic cells during aggression and defeat: relevance to violence, depression and drug abuse. Behav Genet 2011; 41:787-802. [PMID: 21416141 PMCID: PMC3806208 DOI: 10.1007/s10519-011-9462-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 03/04/2011] [Indexed: 01/19/2023]
Abstract
In this review, we examine how experiences in social confrontations alter gene expression in mesocorticolimbic cells. The focus is on the target of attack and threat due to the prominent role of social defeat stress in the study of coping mechanisms and victimization. The initial operational definition of the socially defeated mouse by Ginsburg and Allee (1942) enabled the characterization of key endocrine, cardiovascular, and metabolic events during the initial response to an aggressive opponent and during the ensuing adaptations. Brief episodes of social defeat stress induce an augmented response to stimulant challenge as reflected by increased locomotion and increased extracellular dopamine (DA) in the nucleus accumbens (NAC). Cells in the ventral tegmental area (VTA) that project to the NAC were more active as indicated by increased expression of c-fos and Fos-immunoreactivity and BDNF. Intermittent episodes of social defeat stress result in increased mRNA for MOR in brainstem and limbic structures. These behavioral and neurobiological indices of sensitization persist for several months after the stress experience. The episodically defeated rats also self-administered intravenous cocaine during continuous access for 24 h ("binge"). By contrast, continuous social stress, particularly in the form of social subordination stress, leads to reduced appetite, compromised endocrine activities, and cardiovascular and metabolic abnormalities, and prefer sweets less as index of anhedonia. Cocaine challenges in subordinate rats result in a blunted psychomotor stimulant response and a reduced DA release in NAC. Subordinate rats self-administer cocaine less during continuous access conditions. These contrasting patterns of social stress result from continuous vs. intermittent exposure to social stress, suggesting divergent neuroadaptations for increased vulnerability to cocaine self-administration vs. deteriorated reward mechanisms characteristic of depressive-like profiles.
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Affiliation(s)
- Klaus A Miczek
- Department of Psychology, Tufts University, 530 Boston Ave. (Bacon Hall), Medford, MA 02155, USA.
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Zhang J, Darling RD, Paul IA, Simpson KL, Chen K, Shih JC, Lin RCS. Altered expression of tyrosine hydroxylase in the locus coeruleus noradrenergic system in citalopram neonatally exposed rats and monoamine oxidase a knock out mice. Anat Rec (Hoboken) 2011; 294:1685-97. [PMID: 21901841 DOI: 10.1002/ar.21350] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 11/13/2010] [Indexed: 11/07/2022]
Abstract
In rodents, noradrenergic (NE) locus coeruleus (LC) neurons are well known to express tyrosine hydroxylase (TH) immunoreactivity. However, due to its very low enzyme activity, NE cortical fibers do not typically express TH immunoreactivity, thus dopamine-β-hydroxylase (DBH) immunoreactivity is commonly utilized as a marker for NE cortical fibers. In this study, we performed double and/or triple immunofluorescent staining using antibodies against TH, DBH, and/or norepinephrine transporter (NET) to investigate the altered NE TH expression of cortical fibers in citalopram (CTM)-exposed rats and monoamine oxidase (MAO) A knock out (KO) mice. We have noted the following novel findings: (1) neonatal exposure to the selective serotonin reuptake inhibitor (SSRI) CTM enhanced NE TH immunoreactive fibers throughout the entire neocortex, and a few of them appeared to be hypertrophic; (2) slightly enhanced NE cortical TH immunoreactive fibers were also noted in MAO A KO mice, and many of them revealed varicosities compared with the rather smooth NE cortical TH immunoreactive fibers in wild-type (WT) mice; (3) LC dendrites of MAO A KO mice exhibited beaded morphology compared with the smooth LC dendrites in WT mice. Our findings suggest that both genetic and environmental factors during early development may play a critical role in the regulation and proper function of NE TH expression in the neocortex.
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Affiliation(s)
- Junlin Zhang
- Department of Anatomy, University of Mississippi Medical Center, Jackson, USA
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Ong L, Guan L, Stutz B, Dickson P, Dunkley P, Bobrovskaya L. The effects of footshock and immobilization stress on tyrosine hydroxylase phosphorylation in the rat locus coeruleus and adrenal gland. Neuroscience 2011; 192:20-7. [DOI: 10.1016/j.neuroscience.2011.06.087] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 06/15/2011] [Accepted: 06/30/2011] [Indexed: 01/09/2023]
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Neuroendocrine and neurochemical impact of aggressive social interactions in submissive and dominant mice: implications for stress-related disorders. Int J Neuropsychopharmacol 2010; 13:361-72. [PMID: 19545478 DOI: 10.1017/s1461145709990174] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Social conflicts may engender stress-related behavioural and physiological disturbances in the victims of aggression. In addition, stress-like neurochemical changes and ensuing depressive and anxiety symptoms might also be evident in the perpetrators of aggressive acts. The present investigation assessed basal levels of circulating corticosterone and of brain serotonin (5-HT) and norepinephrine (NE) in pre-identified submissive and dominant mice. In addition, brain neurochemical changes were determined following a single or three 15-min aggressive episodes both in submissive mice and in those that dominated the aggressive interplay. Three minutes after single and repeated confrontations, plasma corticosterone levels and 5-HT utilization within the prefrontal cortex (PFC) and hippocampus were increased to a comparable extent in submissive and dominant animals. Interestingly, however, NE utilization within the PFC and hippocampus was augmented to a greater level in submissive mice. These results suggest that 5-HT neuronal functioning was generally responsive to aggressive events, irrespective of social rank, whereas NE neuronal activity within the PFC and hippocampus was more sensitive to the submissive/dominance attributes of the social situation. It is possible that NE and 5-HT variations associated with an aggressive experience contribute to depressive- and anxiety-like manifestations typically observed after such psychosocial stressors, particularly in submissive mice. However, given that 5-HT changes occur irrespective of social rank, these data suggest that a toll is taken on both submissive and dominant mice, leaving them vulnerable to stress-related pathology.
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McDevitt RA, Szot P, Baratta MV, Bland ST, White SS, Maier SF, Neumaier JF. Stress-induced activity in the locus coeruleus is not sensitive to stressor controllability. Brain Res 2009; 1285:109-18. [PMID: 19524553 DOI: 10.1016/j.brainres.2009.06.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 06/01/2009] [Accepted: 06/04/2009] [Indexed: 10/20/2022]
Abstract
An important factor in determining the adverse consequences of a stress experience is the degree to which an individual can exert control over the stressor. Stressor controllability is known to influence brain norepinephrine levels, but its impact on activity in noradrenergic cell bodies is unknown. In the present study we investigated whether noradrenergic neurons within the locus coeruleus (LC), the major source of forebrain norepinephrine, are sensitive to stressor controllability. We exposed adult male Sprague-Dawley rats to escapable or yoked inescapable tailshock and assessed LC activity by measuring changes in the immediate early gene c-fos and the enzyme tyrosine hydroxylase (TH). We used in situ hybridization to measure levels of c-fos mRNA, TH mRNA, and TH primary transcript in the LC. In all three cases stress exposure increased expression relative to an unstressed homecage control group, but expression did not differ between controllable and uncontrollable stress. To further examine whether stressor controllability influences the number of stress-responsive LC neurons we performed double-label immunohistochemistry for TH and Fos. Again we detected an overall effect of stress, which did not differ between controllable and uncontrollable stress. We conclude that exposure to stress robustly increases expression of TH and c-fos in the LC, but this effect is not influenced by stressor controllability. To the extent that the expression of these genes reflects degree of neuronal activation, our results suggest that stress-induced activity of noradrenergic cell bodies in the LC is not sensitive to stressor controllability.
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Affiliation(s)
- Ross A McDevitt
- Graduate Program in Neurobiology and Behavior, University of Washington, Seattle, Washington, USA
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26
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Abstract
The survival and well-being of all species requires appropriate physiological responses to environmental and homeostatic challenges. The re- establishment and maintenance of homeostasis entails the coordinated activation and control of neuroendocrine and autonomic stress systems. These collective stress responses are mediated by largely overlapping circuits in the limbic forebrain, the hypothalamus and the brainstem, so that the respective contributions of the neuroendocrine and autonomic systems are tuned in accordance with stressor modality and intensity. Limbic regions that are responsible for regulating stress responses intersect with circuits that are responsible for memory and reward, providing a means to tailor the stress response with respect to prior experience and anticipated outcomes.
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27
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Kvetnansky R, Sabban EL, Palkovits M. Catecholaminergic systems in stress: structural and molecular genetic approaches. Physiol Rev 2009; 89:535-606. [PMID: 19342614 DOI: 10.1152/physrev.00042.2006] [Citation(s) in RCA: 359] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Stressful stimuli evoke complex endocrine, autonomic, and behavioral responses that are extremely variable and specific depending on the type and nature of the stressors. We first provide a short overview of physiology, biochemistry, and molecular genetics of sympatho-adrenomedullary, sympatho-neural, and brain catecholaminergic systems. Important processes of catecholamine biosynthesis, storage, release, secretion, uptake, reuptake, degradation, and transporters in acutely or chronically stressed organisms are described. We emphasize the structural variability of catecholamine systems and the molecular genetics of enzymes involved in biosynthesis and degradation of catecholamines and transporters. Characterization of enzyme gene promoters, transcriptional and posttranscriptional mechanisms, transcription factors, gene expression and protein translation, as well as different phases of stress-activated transcription and quantitative determination of mRNA levels in stressed organisms are discussed. Data from catecholamine enzyme gene knockout mice are shown. Interaction of catecholaminergic systems with other neurotransmitter and hormonal systems are discussed. We describe the effects of homotypic and heterotypic stressors, adaptation and maladaptation of the organism, and the specificity of stressors (physical, emotional, metabolic, etc.) on activation of catecholaminergic systems at all levels from plasma catecholamines to gene expression of catecholamine enzymes. We also discuss cross-adaptation and the effect of novel heterotypic stressors on organisms adapted to long-term monotypic stressors. The extra-adrenal nonneuronal adrenergic system is described. Stress-related central neuronal regulatory circuits and central organization of responses to various stressors are presented with selected examples of regulatory molecular mechanisms. Data summarized here indicate that catecholaminergic systems are activated in different ways following exposure to distinct stressful stimuli.
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Affiliation(s)
- Richard Kvetnansky
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic.
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Russell JA, Douglas AJ, Brunton PJ. Reduced Hypothalamo-pituitary-adrenal Axis Stress Responses in Late Pregnancy. Ann N Y Acad Sci 2008; 1148:428-38. [DOI: 10.1196/annals.1410.032] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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29
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Lee CH, Choi JH, Chung DW, Hwang IK, Yoon YS, Won MH, Lee IS. Reduced immunoreactivity of tyrosine hydroxylase in the hypothalamic paraventricular nucleus of the seizure sensitive gerbil. J Vet Med Sci 2008; 70:645-8. [PMID: 18628612 DOI: 10.1292/jvms.70.645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We compared the immunoreactivity and numbers of tyrosine hydroxylase (TH) immunoreactive neurons and neuropil in the paraventricular nucleus (PVN) of the hypothalamus between the seizure sensitive (SS) and seizure resistant (SR) gerbils. The distributional pattern of TH immunoreactivity was similar in both groups: TH immunoreactivity was seen mainly in magnocellular neurons of the PVN. However, total TH immunoreactivity in the neurons and neuropil in the SS gerbils was significantly lower than that in the SR gerbils. In addition, the number of TH immunoreactive neurons in the SS gerbils was also much lower than those in the SR gerbils. These results indicate that SS gerbils have a low TH immunoreactivity in the hypothalamic PVN compared with that in SR gerbils.
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Affiliation(s)
- Choong Hyun Lee
- Department of Anatomy and Cell Biology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul, South Korea
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Zhao Y, Ma R, Shen J, Su H, Xing D, Du L. A mouse model of depression induced by repeated corticosterone injections. Eur J Pharmacol 2007; 581:113-20. [PMID: 18184609 DOI: 10.1016/j.ejphar.2007.12.005] [Citation(s) in RCA: 233] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2007] [Revised: 11/26/2007] [Accepted: 12/06/2007] [Indexed: 11/17/2022]
Abstract
A rat model of depression has been recently developed by exogenous corticosterone administration. In this study, we further determined whether corticosterone administration also increased depression-like behavior in mice and explored the brain biochemical consequences of exposure to this administration paradigm. Mice received repeated injections of vehicle and 20 mg/kg of corticosterone for 1, 3 and 5 weeks, and then were subjected to the forced-swim and tail suspension tests. The results showed that repeated corticosterone injections increased immobility behavior in the forced-swim and tail suspension tests in a time-dependent manner. Meanwhile, this injection paradigm produced a time-related effect on tyrosine hydroxylase (TH) levels in the hippocampus of mice. These results are consistent with correlations in stress-induced depression models, and suggest that the repeated corticosterone injection paradigm provides a useful and reliable mouse model within which to further study the role of stress and glucocorticoids in depressive illness, as well as screen for antidepressants or preventive drugs.
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Affiliation(s)
- Yunan Zhao
- Laboratory of Pharmaceutical Sciences, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China
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Sabban EL, Serova LI. Influence of prior experience with homotypic or heterotypic stressor on stress reactivity in catecholaminergic systems. Stress 2007; 10:137-43. [PMID: 17514582 DOI: 10.1080/10253890701404078] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Here we review how prior experience with stress alters the response to a subsequent homotypic or heterotypic stressor, focusing on the catecholaminergic systems in the adrenal medulla and the locus coeruleus (LC). The changes in response to homotypic stress differ depending on the stressor applied. With immobilization stress (IMO), transcriptional responses in the adrenal medulla to a single exposure are pronounced and several of the transcription factors and signaling kinases induced or activated are reviewed and compared to the longer term alterations with repeated stress, consistent with persistent activation of gene expression of catecholamine (CA) biosynthetic enzymes. In the LC, transcriptional and post-transcriptional activation of gene expression are shown to be important. Repeated IMO stress triggers further activation of a number of signalling pathways. Neither adrenal medulla nor LC display habituation to long term repeated stress. In contrast, gene expression for CA biosynthetic enzymes habituates to prolonged cold stress in the adrenal medulla and LC, but displays an exaggerated response with exposure to a novel or heterotypic stressor such as IMO. Some of the transcriptional pathways displaying sensitization are described.
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Affiliation(s)
- Esther L Sabban
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY, USA.
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Miner LH, Jedema HP, Moore FW, Blakely RD, Grace AA, Sesack SR. Chronic stress increases the plasmalemmal distribution of the norepinephrine transporter and the coexpression of tyrosine hydroxylase in norepinephrine axons in the prefrontal cortex. J Neurosci 2006; 26:1571-8. [PMID: 16452680 PMCID: PMC6675488 DOI: 10.1523/jneurosci.4450-05.2006] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Norepinephrine (NE) potently modulates the cognitive and affective functions of the prefrontal cortex (PFC). Deficits in NE transmission are implicated in psychiatric disorders, and antidepressant drugs that block the NE transporter (NET) effectively treat these conditions. Our initial ultrastructural studies of the rat PFC revealed that most NE axons (85-90%) express NET primarily within the cytoplasm and lack detectable levels of the synthetic enzyme tyrosine hydroxylase (TH). In contrast, the remaining 10-15% of PFC NE axons exhibit predominantly plasmalemmal NET and evident TH immunoreactivity. These unusual characteristics suggest that most PFC NE axons have an unrecognized, latent capacity to enhance the synthesis and recovery of transmitter. In the present study, we used dual-labeling immunocytochemistry and electron microscopy to examine whether chronic cold stress, a paradigm that persistently increases NE activity, would trigger cellular changes consistent with this hypothesis. After chronic stress, neither the number of profiles exhibiting NET labeling nor their size was changed. However, the proportion of plasmalemmal NET nearly doubled from 29% in control animals to 51% in stressed rats. Moreover, the expression of detectable TH in NET-labeled axons increased from only 13% of profiles in control rats to 32% of profiles in stressed animals. Despite the consistency of these findings, the magnitude of the changes varied across individual rats. These data represent the first demonstration of activity-dependent trafficking of NET and expression of TH under physiological conditions and have important implications for understanding the pathophysiology and treatment of stress-related affective disorders.
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34
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Hebert MA, Serova LI, Sabban EL. Single and repeated immobilization stress differentially trigger induction and phosphorylation of several transcription factors and mitogen-activated protein kinases in the rat locus coeruleus. J Neurochem 2005; 95:484-98. [PMID: 16190871 DOI: 10.1111/j.1471-4159.2005.03386.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The locus coeruleus (LC) is a critical stress-responsive location that mediates many of the responses to stress. We used immunoblotting and immunohistochemistry to investigate changes in induction and phosphorylation of several transcription factors and kinases in the LC that may mediate the stress-triggered induction of tyrosine hydroxylase (TH) transcription. Rats were exposed to single or repeated immobilization stress (IMO) for brief (5 min), intermediate (30 min) or sustained (2 h) duration. Single IMO elicited rapid induction of c-Fos and phosphorylation of cyclic AMP response element-binding protein (CREB) without changing the expression of early growth response (Egr)1, Fos-related antigen (Fra)-2 or phosphorylated activating transcription factor-2. Repeated IMO triggered increased phosphorylation and levels of CREB along with transient induction of c-Fos and increased Fra-2 expression. Several mitogen-activated protein kinases were activated by repeated IMO, shown by increased phosphorylation of p38, c-Jun N-terminal kinase (JNK)1/2/3 and extracellular signal-regulated kinase (ERK1/2). ERK1 was the major isoform expressed, and ERK2 the predominant isoform phosphorylated. Repeated IMO elicited hyperphosphorylation of ERK1/2 selectively in TH immunoreactive neurons, with substantial nuclear localization. These distinct alterations in transcriptional pathways following repeated compared with single stress may be involved in mediating long-lasting neuronal remodeling and are implicated in the mechanisms by which acute beneficial responses to stress are converted into prolonged adaptive or maladaptive responses.
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Affiliation(s)
- Meleik A Hebert
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595, USA
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Cory-Slechta DA. Studying Toxicants as Single Chemicals: Does this Strategy Adequately Identify Neurotoxic Risk? Neurotoxicology 2005; 26:491-510. [PMID: 16112317 DOI: 10.1016/j.neuro.2004.12.007] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2004] [Revised: 11/15/2004] [Accepted: 12/17/2004] [Indexed: 10/25/2022]
Abstract
Despite the fact that virtually all chemicals exposure of humans are to mixtures, and that these mixed exposures occur in the context of numerous other risk modifiers, our current understanding of human health risks is based almost entirely on the evaluation of chemicals studied in isolation. This paper describes findings from our collaborative studies that prompt questions about these approaches in the context of neurotoxicology. The first section describes studies investigating the interactions of maternal Pb exposure with maternal stress. Examined across a range of outcome measures, it shows that maternal Pb can modulate the effects of maternal stress, and, conversely, stress modifies the effects of Pb. Further, effects of Pb+stress could be detected in the absence of an effect of either risk factor alone, and, moreover, the profile of effects of Pb alone differs notably from that of Pb+stress. Collectively, interactions were not systematic, but differed by brain region, gender and outcome measure. A second section describes outcomes of studies examining combined exposures to the pesticides paraquat (PQ) and maneb (MB) during development which likewise reveal potentiated effects of combined exposures. They also demonstrate examples of both progressive and cumulative neurotoxicity, including a marked vulnerability following gestational exposure to MB, to the effects of PQ, a pesticide with no structural relationship to MB. The ability of current hazard identification and risk assessment approaches to adequately identify and encompass such effects remains an important unanswered question. One consideration proposed for further evaluating potential interactions that may be of significance for the nervous system is based on a multi-hit hypothesis. It hypothesizes that the brain may readily compensate for the effects of an individual chemical itself acting on a particular target system, but when multiple target or functional sites within that one system are attacked by different mechanisms (i.e., multiple chemical exposures or chemical exposures combined with other risk factors), homeostatic capabilities may be restricted, thereby leading to sustained or cumulative damage.
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Affiliation(s)
- Deborah A Cory-Slechta
- Environmental and Occupational Health Sciences Institute, A joint Institute of Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854, USA.
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Douglas AJ. Central noradrenergic mechanisms underlying acute stress responses of the Hypothalamo-pituitary-adrenal axis: adaptations through pregnancy and lactation. Stress 2005; 8:5-18. [PMID: 16019594 DOI: 10.1080/10253890500044380] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Hypothalamo-pituitary-adrenal axis responses to stress are attenuated perinatally, and may contribute towards conservation of energy stores and/or prevention of overexposure to glucocorticoid and its adverse effects in the developing fetus/neonate. Previous work has shown that reduced central drive to the hypothalamo-pituitary-adrenal axis is responsible, since parvocellular paraventricular nucleus neurone responses are reduced. One of the main input pathways to the paraventricular nucleus that is activated by the majority of stressors is the brainstem noradrenergic system. This review outlines key noradrenergic mechanisms that mediate hypothalamo-pituitary-adrenal axis responses to acute stress, and addresses aspects of their adaptation in pregnancy and lactation that can explain the stress hyporesponsiveness at that time. In summary, reduced noradrenaline release and adrenergic receptor expression in the paraventricular nucleus may lead to reduced sensitivity of the hypothalamo-pituitary-adrenal axis to adrenergic antagonists and agonists and its responses to stress. While there are subtle differences in these changes between pregnancy and lactation, it would appear that reduced effectiveness of the noradrenergic input can at least partly account for the reduced hypothalamo-pituitary-adrenal axis responses both pre- and post-natally.
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Affiliation(s)
- Alison J Douglas
- Laboratory of Neuroendocrinology, Centre for Integrative Physiology, SBCLS, College of Medicine and Veterinary Medicine, University of Edinburgh, Hugh Robson Building, George Square, UK.
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Zhu MY, Wang WP, Baldessarini RJ, Kim KS. Effects of desipramine treatment on tyrosine hydroxylase gene expression in cultured neuroblastoma cells and rat brain tissue. ACTA ACUST UNITED AC 2005; 133:167-75. [PMID: 15710233 DOI: 10.1016/j.molbrainres.2004.10.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2004] [Indexed: 11/26/2022]
Abstract
Activity and expression of tyrosine hydroxylase (TH), the rate-limiting enzyme for catecholamine synthesis, are modified in response to antidepressant-treatment. We examined effects of the selective norepinephrine-transporter (NET) inhibitor antidepressant desipramine (DMI) on expression of TH in human neuroblastoma cells (SK-N-BE[2]M17) and in rat brain regions. TH mRNA levels were determined by Northern blot in vitro, and by in situ hybridization ex vivo; TH protein levels were measured by western blot. Brief exposure of neuroblastoma cells to 0 vs. 5, 50, or 500 nM of DMI had little effect on TH mRNA levels, but exposure to 50 and 500 nM DMI for 14 days increased the mRNA by up to 72%, with a continuous rise from 3 to 14 days of exposure to 500 nM DMI. In contrast, 500 nM DMI led to an initial slight increase, followed by a continuous and sustained decrease in TH protein level by up to 53%, from day 3 to day 14. Daily treatment of rats with DMI (10 mg/kg, i.p.) for 3 or 14 days significantly increased postmortem cerebral TH mRNA in the locus coeruleus (LC) area by 47-68%. Again, TH protein concentrations in LC decreased at 3 and 14 days, by 25-40%, with transient significant reduction in amygdala tissue after 3 days of treatment that were not sustained. These findings indicate that DMI exerts complex, typically opposite and perhaps compensatory, gradually evolving effects on the expression of TH protein (decreases) and its message (increases), possibly in response to increased synaptic availability of NE.
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Affiliation(s)
- Meng-Yang Zhu
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS 39216, USA.
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Panayotacopoulou MT, Malidelis Y, van Heerikhuize J, Unmehopa U, Swaab D. Individual differences in the expression of tyrosine hydroxylase mRNA in neurosecretory neurons of the human paraventricular and supraoptic nuclei: positive correlation with vasopressin mRNA. Neuroendocrinology 2005; 81:329-38. [PMID: 16210867 DOI: 10.1159/000088760] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Accepted: 08/05/2005] [Indexed: 11/19/2022]
Abstract
Previous studies indicated that in the human paraventricular nucleus (PVN) and in the supraoptic nucleus (SON) tyrosine hydroxylase (TH) - the first and rate-limiting enzyme in catecholamine synthesis - is localized mainly in magnocellular neurosecretory neurons. Individual differences were observed among control subjects in number and distribution of TH-immunoreactive (IR) perikarya, indicating that antemortem factors may regulate TH expression. Since a large number of TH-IR perikarya were observed in subjects who suffered from somatic illnesses leading to prolonged osmotic or nonosmotic stimulation of vasopressin (VP) release, we suggested that TH expression is related to the activation of VP neurons. The purpose of our study was to apply (1) in situ hybridization for TH mRNA on human PVN and SON to investigate how the previously reported individual differences in TH protein expression are depicted at the transcriptional level and (2) quantitative TH immunohistochemistry and in situ hybridization for VP mRNA throughout the dorsolateral part of the SON (dl-SON) in order to elucidate whether indeed expression of TH in neurosecretory nuclei depends on activation of VP neurons. Postmortem formalin-fixed, paraffin-embedded hypothalamic sections of 16 control subjects were studied for TH protein and TH and VP mRNAs. For 6 of the above cases, the number of TH-IR neurons and the total VP mRNA levels were estimated throughout the entire dl-SON using an image analysis system. Individual variation was observed in TH mRNA expression which appears to parallel the expression of TH-protein. Using Spearman's bivariate test, a positive correlation was found between the number of TH-IR- and TH-mRNA-expressing neurons in both PVN and SON (p < 0.01) as well as between the number of TH-IR neurons and the total VP mRNA in the dl-SON (p < 0.05). Our results show (1) that the individual variability in the number of TH-IR neurons within the neurosecretory nuclei might be due to differential expression and/or stability of TH mRNA and (2) that expression of TH-immunoreactivity in human PVN and SON depends on the activation of VP neurons.
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Woolley SC, Sakata JT, Crews D. Tyrosine hydroxylase expression is affected by sexual vigor and social environment in male Cnemidophorus inornatus. J Comp Neurol 2004; 476:429-39. [PMID: 15282714 DOI: 10.1002/cne.20236] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Although the distribution of catecholamine-synthesizing cells has been described for a variety of taxa, less is known about the functional significance of particular populations in nonmammalian species, especially reptiles. To understand the role of these populations in the display of social behaviors in lizards, we studied the interactive effects of sexual vigor (sexually vigorous vs. sluggish) and social condition (housing in isolation vs. with females) on the number and somal areas of cells expressing tyrosine hydroxylase (TH), a rate-limiting enzyme in catecholamine synthesis, in male whiptail lizards, Cnemidophorus inornatus. We found that, regardless of social condition, sexually vigorous males had more TH-immunoreactive (TH-ir) cells in the dorsal hypothalamus (DH) relative to sluggish males. Sexually vigorous males also had more TH-ir cells in the substantia nigra pars compacta (SNpc), but this difference was significant only among males housed with females. Sexually vigorous males that had been housed with females had smaller TH-ir cells in the preoptic area (POA) than vigorous males housed in isolation. On the other hand, no significant differences were found in the anterior hypothalamus. These results highlight the regional heterogeneity in the plasticity of TH expression and suggest that, just as in other species, the DH, SNpc, and POA might be involved in the expression of social behaviors and in behavioral plasticity following social experiences in lizards.
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Affiliation(s)
- S C Woolley
- Section of Integrative Biology, University of Texas at Austin, Austin, Texas 78712, USA.
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Miczek KA, Covington HE, Nikulina EM, Hammer RP. Aggression and defeat: persistent effects on cocaine self-administration and gene expression in peptidergic and aminergic mesocorticolimbic circuits. Neurosci Biobehav Rev 2004; 27:787-802. [PMID: 15019428 DOI: 10.1016/j.neubiorev.2003.11.005] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The question of how ostensibly aversive social stress experiences in an aggressive confrontation can persistently increase intense drug taking such as cocaine 'bingeing' needs to be resolved. The biology of social conflict highlights distinctive behavioral, cardiovascular and endocrine profiles of dominant and subordinate animals, as seen also in rodents and primates under laboratory conditions. In contrast to continuous subordination stress that produces chronic pathophysiological consequences and often is fatal, animals adapt to brief episodes of social defeat stress, but show enduring functional activation in mesocorticolimbic microcircuits. Uncontrollable episodes of social defeat stress produce long-lasting tolerance to opiate analgesia and, concurrently, behavioral sensitization to challenges with either amphetamine or cocaine. One week after a single social defeat stress, cross-sensitization to cocaine is evident in terms of enhanced motor activity as well as in terms of increased Fos labeling in the periaqueductal grey area, the locus coeruleus, and the dorsal raphe nuclei. When challenged with a low amphetamine dose, the behavioral and neural effects of repeated brief episodes of social defeat stress persist for months. Previous exposure to social defeat stress can (1). significantly shorten the latency to acquire cocaine self-administration, (2). maintain this behavior at low cocaine unit doses, (3). significantly increase the levels of cocaine taking during a 24 h binge of continuous drug availability, (4). dysregulate the timing of consecutive infusions, and (5). abolish the circadian pattern of self-administration. Amygdaloid modulation, especially originating from central and basolateral nuclei, of dopaminergic pathways via peptidergic and glutamatergic neurons appears to be a key mechanism by which social defeat stress affects cocaine self-administration. Social stress alters the feedback from prefrontal cortex and thereby may contribute to the dysregulation of dopaminergic activity that is necessary for cocaine self-administration.
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Affiliation(s)
- Klaus A Miczek
- Department of Psychology, Tufts University, Bacon Hall, 530 Boston Avenue, Medford, MA 02155, USA.
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Featherby T, Lawrence AJ. Chronic cold stress regulates ascending noradrenergic pathways. Neuroscience 2004; 127:949-60. [PMID: 15312907 DOI: 10.1016/j.neuroscience.2004.06.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2004] [Indexed: 12/15/2022]
Abstract
Chronic exposure to cold in rats alters the activity of locus coeruleus (LC) neurons. In this study we aimed to examine the cellular effect of cold stress on catecholamine neurons, and determine whether this is specific to the LC compared with other catecholamine cell groups. Male Sprague-Dawley rats were subjected to 21 days of isolation under ambient conditions, chronic cold exposure at 5 degrees C, or after chronic cold followed by return to ambient temperature for 7 or 14 days. In the LC, chronic cold exposure significantly reduced tyrosine hydroxylase (TH) mRNA expression by approximately 45% compared with control rats, and remained significantly reduced (approximately 36%) after return to ambient conditions for 7 days; however, expression returned to normal after 14 days' recovery. There were no significant changes in TH mRNA in the substantia nigra or ventral tegmental area. Chronic cold increased expression of alpha2A adrenoceptor mRNA in the LC (approximately 27%). There were decreases in alpha2A expression in the nucleus tractus solitarius; however, this was seen only in rats returned to ambient conditions for 7 days. Additionally, alpha2A mRNA in the caudal ventrolateral medulla (A1 region) increased following cold exposure (approximately 84%) compared with controls. Binding of [125I]iodoclonidine to alpha2-like protein increased in the olfactory bulbs but decreased in the medial amygdala following cold exposure. Collectively, these data indicate robust effects of cold on central catecholamine neurons, not necessarily specific to the LC.
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Affiliation(s)
- T Featherby
- Department of Pharmacology, Monash University, Clayton, Australia
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Kvetnansky R, Rusnak M, Dronjak S, Krizanova O, Sabban EL. Effect of novel stressors on tyrosine hydroxylase gene expression in the adrenal medulla of repeatedly immobilized rats. Neurochem Res 2003; 28:625-30. [PMID: 12675153 DOI: 10.1023/a:1022846012174] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The activity of the sympathetic-adrenomedullary system in rats submitted to novel stressors after prior repeated or chronic stress exposure is poorly understood. The purpose of the present work was to investigate changes in adrenomedullary (AM) tyrosine hydroxylase (TH) gene expression after a single or long-term repeated exposure of rats to immobilization stress (IMMO; 42 times), as well as in repeatedly immobilized rats (41 times) exposed once to various novel heterotypic stressors. Cold exposure for 5 h, administration of insulin (INS, 51U), or 2-deoxyglucose (2DG, 500 mg/kg) were used as novel stressors. A single exposure to cold, INS, or 2DG produced transient increases in TH mRNA levels in AM. Animals exposed to repeated homotypic IMMO stress showed permanently increased TH mRNA levels, TH activity, and protein levels; however, an exposure of such animals to heterotypic novel stressors did not induce any further changes. Thus the observed differences in TH mRNA levels in the AM of control rats and long-term repeatedly IMMO rats suggest that an adaptation to this stressor is displayed by a permanently increased TH gene expression, TH activity, and protein level. The exposure of repeatedly IMMO rats to a single episode of novel stressor does not induce exaggerated responses in TH gene expression, as some other stressors do. The mechanism of this finding could involve a central regulation and/or adrenomedullary signaling pathway(s), leading to additional modifications or accumulation of transcription factors. The precise mechanism(s) of this phenomenon remains to be elucidated.
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Affiliation(s)
- R Kvetnansky
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska 3, 833 06 Bratislava, Slovak Republic.
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Herman JP, Renda A, Bodie B. Norepinephrine-gamma-aminobutyric acid (GABA) interaction in limbic stress circuits: effects of reboxetine on GABAergic neurons. Biol Psychiatry 2003; 53:166-74. [PMID: 12547473 DOI: 10.1016/s0006-3223(02)01449-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Reboxetine is a selective norepinephrine (NE) reuptake inhibitor that exerts significant antidepressant action. The current study assessed norepinephrine-gamma-aminobutyric acid (GABA)-ergic mechanisms in reboxetine action, examining glutamic acid decarboxylase (GAD) mRNA expression in limbic neurocircuits following reboxetine within the context of chronic stress. METHODS Male rats received 25 mg/kg reboxetine/day, p.o. Reboxetine and vehicle animals were exposed to 1 week of variable stress exposure or handling. Behavioral responses to stress (open field) were tested on day 7, and animals were killed on day 8 to assess neuroendocrine stress responses and limbic GAD65/67 mRNA regulation (in situ hybridization). RESULTS Reboxetine significantly decreased behavioral reactivity in the open field. Reboxetine administration did not affect expression of GAD65/67 mRNA in handled rats; however, administration to stressed animals reduced GAD67 (but not GAD65) mRNA in the medial amygdaloid nucleus, posteromedial bed nucleus of the stria terminalis, and dentate gyrus. In contrast, GAD65 mRNA expression was increased by reboxetine in the lateral septum of stressed animals. CONCLUSIONS Norepinephrine pathways appear to modulate synthesis of GABA in central limbic stress circuits. Decreases in GABA synthetic capacity suggest reduced activation of stress-excitatory pathways and enhanced activation of stress-inhibitory circuits, and is consistent with a role for GABA in the antidepressant efficacy of NE reuptake inhibitors.
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Affiliation(s)
- James P Herman
- Department of Psychiatry, University of Cincinnati Medical Center, (JPH, BB), Cincinnati, Ohio 45267-0559, USA
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Jedema HP, Grace AA. Chronic exposure to cold stress alters electrophysiological properties of locus coeruleus neurons recorded in vitro. Neuropsychopharmacology 2003; 28:63-72. [PMID: 12496941 DOI: 10.1038/sj.npp.1300020] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chronic stress exposure can alter central noradrenergic function. Previously, we reported that in chronically cold-exposed rats the release of norepinephrine and electrophysiological activation of locus coeruleus (LC) neurons is enhanced in response to multiple excitatory stimuli without alterations in basal activity. In the present studies, we used in vitro intracellular recording techniques to explore the effect of chronic cold exposure on the basal and evoked electrophysiological properties of LC neurons in horizontal slices of the rat brainstem. Consistent with our findings from in vivo experiments, chronic cold exposure did not affect basal firing rate. Furthermore, gross morphology of LC neurons and spike waveform characteristics were similar in slices from control and previously cold-exposed rats. However, excitability in response to intracellular current injection and input resistance were larger in slices from previously cold-exposed rats. In addition, the accommodation of spike firing in response to sustained current injection was smaller and the period of postactivation inhibition appeared to be less in LC neurons from cold-exposed rats. These data demonstrate that the stress-evoked sensitization of LC neurons observed in vivo is at least in part maintained in the slice preparation and suggest that alterations in electrophysiological properties of LC neurons contribute to the chronic stress-induced sensitization of central noradrenergic function observed in vivo. Furthermore, the present data suggest that an alteration in autoinhibitory control of LC activity is involved in the chronic stress-induced alterations. The enhanced functional capacity of LC neurons following cold exposure of rats may represent a unique model to study the mechanisms underlying the alterations in central noradrenergic function observed in humans afflicted with mood and anxiety disorders.
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Affiliation(s)
- Hank P Jedema
- Department of Neuroscience, University of Pittsburgh, PA 15260, USA.
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Panayotacopoulou MT, Malidelis YI, Fliers E, Bouras C, Ravid R, Swaab DF. Increased expression of tyrosine hydroxylase immunoreactivity in paraventricular and supraoptic neurons in illnesses with prolonged osmotic or nonosmotic stimulation of vasopressin release. Neuroendocrinology 2002; 76:254-66. [PMID: 12411742 DOI: 10.1159/000065949] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Our previous studies indicated that in the human paraventricular (PVN) and supraoptic (SON) nuclei, tyrosine hydroxylase (TH)--the first and rate-limiting enzyme in catecholamine synthesis--is localized mainly in magnocellular neurons and that antemortem factors regulate its expression. The purpose of the present study was to investigate the distribution of TH-immunoreactive (TH-IR) perikarya of the hypothalami of a large sample of well-documented adult subjects without neurological, psychiatric or endocrinological disease in order to identify factors that could regulate the expression of TH in the human neurosecretory neurons. Our material consisted of the hypothalami of 38 subjects studied immunohistochemically for TH using the peroxidase-antiperoxidase method. Striking individual differences were observed among the subjects studied concerning the number and distribution of TH-IR perikarya within the PVN and SON. These differences were evident throughout the entire rostrocaudal length of the hypothalamus and appeared to be related neither to the age or sex of the subjects nor to the postmortem interval or staining procedures. In the sample studied, a large number of TH-IR perikarya were observed specifically in all subjects that had suffered from right-sided heart failure due to pulmonary hypertension, liver cirrhosis or dehydration. In all the above illnesses, increased production and secretion of vasopressin (VP) are reported to occur due to a decrease in 'effective' blood volume or to osmotic stimulation. We conclude that somatic illnesses leading to prolonged osmotic or nonosmotic stimulation of VP release may induce increased expression of TH immunoreactivity in the human neurosecretory neurons related to neuronal activation.
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Bhatnagar S, Huber R, Nowak N, Trotter P. Lesions of the posterior paraventricular thalamus block habituation of hypothalamic-pituitary-adrenal responses to repeated restraint. J Neuroendocrinol 2002; 14:403-10. [PMID: 12000546 DOI: 10.1046/j.0007-1331.2002.00792.x] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We examined the role of the posterior division of the paraventricular nucleus of the thalamus (pPVTh) in habituation of hypothalamic-pituitary-adrenal (HPA) responses to repeated restraint. Habituation refers to the decrement in HPA activity that occurs with repeated exposure to the same or homotypic stressor. To date, the pPVTh has been shown to inhibit the enhanced or facilitated HPA responses to novel, heterotypic restraint in previously chronically cold stressed rats. We hypothesized that the pPVTh also inhibits HPA activity under conditions of habituation. In the first experiment, we lesioned the pPVTh and examined adrenocorticotropic hormone (ACTH) and corticosterone responses to the first or eighth restraint exposure. In sham-lesioned rats, we found lower ACTH and corticosterone responses to the eighth period of 30 min restraint compared to the first exposure, evidence for habituation. In pPVTh-lesioned rats, there was no difference in ACTH and corticosterone responses to the eighth compared to the first restraint exposure. Therefore, pPVTh lesions prevented the habituation of HPA responses to repeated restraint. In the second experiment, we examined whether habituation to restraint is observable in response to an acute, single restraint on day 28 in sham and pPVTh lesioned rats that were exposed to restraint only on days 1 through 8. In this experiment, we replicated the results from the first experiment, and found evidence that habituation to restraint can be observed weeks after chronic stress has been terminated. Furthermore, pPVTh lesions had no additional effects on HPA responses to acute stress on day 28. In summary, pPVTh lesions inhibit habituation of HPA activity to a homotypic stressor, without altering HPA responses to the first restraint. Thus, the intact pPVTh inhibits HPA activity under conditions of habituation, as well as facilitation, and represents an important regulator of HPA activity under conditions of chronic stress.
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Affiliation(s)
- S Bhatnagar
- Department of Psychology and the Neuroscience Program, University of Michigan, Ann Arbor 48109-1109, USA
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Park CR, Campbell AM, Diamond DM. Chronic psychosocial stress impairs learning and memory and increases sensitivity to yohimbine in adult rats. Biol Psychiatry 2001; 50:994-1004. [PMID: 11750896 DOI: 10.1016/s0006-3223(01)01255-0] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND It is well known that intense and prolonged stress can produce cognitive impairments and hippocampal damage and increase noradrenergic activity in humans. This study investigated the hypothesis that chronic psychosocial stress would affect behavior, drug sensitivity, and hippocampal-dependent learning and memory in rats. The work provides a novel connection between animal and human studies by evaluating the effects of stress on a rat's response to yohimbine, an alpha(2) adrenergic receptor antagonist. METHODS Rats were exposed to a cat for 5 weeks and randomly housed with a different group of cohorts each day (psychosocial stress). The effects of the stress manipulations were then assessed on open field behavior, spatial learning and memory in the radial arm water maze and the behavioral response to a low dose of yohimbine (1.5 mg/kg). RESULTS Stressed rats displayed impaired habituation to a novel environment, heightened anxiety, and increased sensitivity to yohimbine. In addition, the stressed rats exhibited impaired learning and memory. CONCLUSIONS There are commonalities between the current findings on stressed rats and from studies on traumatized people. Thus, psychosocial stress manipulations in rats may yield insight into the basis of cognitive and neuroendocrine disturbances that commonly occur in people with anxiety disorders.
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Affiliation(s)
- C R Park
- Department of Psychology, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620, USA
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Lupien SJ, Lepage M. Stress, memory, and the hippocampus: can't live with it, can't live without it. Behav Brain Res 2001; 127:137-58. [PMID: 11718889 DOI: 10.1016/s0166-4328(01)00361-8] [Citation(s) in RCA: 343] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Since the 1968s discovery of receptors for stress hormones (corticosteroids) in the rodent hippocampus, a tremendous amount of data has been gathered on the specific and somewhat isolated role of the hippocampus in stress reactivity. The hippocampal sensitivity to stress has also been extended in order to explain the negative impact of stress and related stress hormones on animal and human cognitive function. As a consequence, a majority of studies now uses the stress-hippocampus link as a working hypothesis in setting up experimental protocols. However, in the last decade, new data were gathered showing that stress impacts on many cortical and subcortical brain structures other than the hippocampus. The goal of this paper is to summarize the four major arguments previously used in order to confirm the stress-hippocampus link, and to describe new data showing the implication of other brain regions for each of these previously used arguments. The conclusion of this analysis will be that scientists should gain from extending the impact of stress hormones to other brain regions, since hormonal functions on the brain are best explained by their modulatory role on various brain structures, rather than by their unique impact on one particular brain region.
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Affiliation(s)
- S J Lupien
- Research Center, Douglas Hospital Research Center, Department of Psychiatry, McGill University, Verdun, Quebec, Canada H4H 1R3.
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Harro J, Oreland L. Depression as a spreading adjustment disorder of monoaminergic neurons: a case for primary implication of the locus coeruleus. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2001; 38:79-128. [PMID: 11750928 DOI: 10.1016/s0165-0173(01)00082-0] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A model for the pathophysiology of depression is discussed in the context of other existing theories. The classic monoamine theory of depression suggests that a deficit in monoamine neurotransmitters in the synaptic cleft is the primary cause of depression. More recent elaborations of the classic theory also implicitly include this postulate, other theories of depression frequently prefer to depart from the monoamine-based model altogether. We suggest that the primary defect emerges in the regulation of firing rates in brainstem monoaminergic neurons, which brings about a decrease in the tonic release of neurotransmitters in their projection areas, an increase in postsynaptic sensitivity, and concomitantly, exaggerated responses to acute increases in the presynaptic firing rate and transmitter release. It is proposed that the initial defect involves, in particular, the noradrenergic innervation from the locus coeruleus (LC). Dysregulation of the LC projection activities may lead in turn to dysregulation of serotonergic and dopaminergic neurotransmission. Failure of the LC function could explain the basic impairments in the processing of novel information, intensive processing of irrational beliefs, and anxiety. Concomitant impairments in the serotonergic neurotransmission may contribute to the mood changes and reduction in the mesotelencephalic dopaminergic activity to loss of motivation, and anhedonia. Dysregulation of CRF and other neuropeptides such as neuropeptide Y, galanin and substance P may reinforce the LC dysfunction and thus further weaken the adaptivity to stressful stimuli.
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Affiliation(s)
- J Harro
- Department of Psychology, University of Tartu, Tiigi 78, EE-50410 Tartu, Estonia.
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McEwen BS. Neurobiology of Interpreting and Responding to Stressful Events: Paradigmatic Role of the Hippocampus. Compr Physiol 2001. [DOI: 10.1002/cphy.cp070409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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