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Raise-Abdullahi P, Meamar M, Vafaei AA, Alizadeh M, Dadkhah M, Shafia S, Ghalandari-Shamami M, Naderian R, Afshin Samaei S, Rashidy-Pour A. Hypothalamus and Post-Traumatic Stress Disorder: A Review. Brain Sci 2023; 13:1010. [PMID: 37508942 PMCID: PMC10377115 DOI: 10.3390/brainsci13071010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/25/2023] [Accepted: 06/28/2023] [Indexed: 07/30/2023] Open
Abstract
Humans have lived in a dynamic environment fraught with potential dangers for thousands of years. While fear and stress were crucial for the survival of our ancestors, today, they are mostly considered harmful factors, threatening both our physical and mental health. Trauma is a highly stressful, often life-threatening event or a series of events, such as sexual assault, war, natural disasters, burns, and car accidents. Trauma can cause pathological metaplasticity, leading to long-lasting behavioral changes and impairing an individual's ability to cope with future challenges. If an individual is vulnerable, a tremendously traumatic event may result in post-traumatic stress disorder (PTSD). The hypothalamus is critical in initiating hormonal responses to stressful stimuli via the hypothalamic-pituitary-adrenal (HPA) axis. Linked to the prefrontal cortex and limbic structures, especially the amygdala and hippocampus, the hypothalamus acts as a central hub, integrating physiological aspects of the stress response. Consequently, the hypothalamic functions have been attributed to the pathophysiology of PTSD. However, apart from the well-known role of the HPA axis, the hypothalamus may also play different roles in the development of PTSD through other pathways, including the hypothalamic-pituitary-thyroid (HPT) and hypothalamic-pituitary-gonadal (HPG) axes, as well as by secreting growth hormone, prolactin, dopamine, and oxytocin. This review aims to summarize the current evidence regarding the neuroendocrine functions of the hypothalamus, which are correlated with the development of PTSD. A better understanding of the role of the hypothalamus in PTSD could help develop better treatments for this debilitating condition.
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Affiliation(s)
| | - Morvarid Meamar
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran
| | - Abbas Ali Vafaei
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran
- Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Maryam Alizadeh
- Department of Basic Medical Sciences, Faculty of Medicine, Qom Medical Sciences, Islamic Azad University, Qom, Iran
| | - Masoomeh Dadkhah
- Pharmaceutical Sciences Research Center, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Sakineh Shafia
- Immunogenetics Research Center, Department of Physiology, Mazandaran University of Medical Sciences, Sari, Iran
| | | | - Ramtin Naderian
- Student Research Committee, Semnan University of Medical Sciences, Semnan, Iran
| | - Seyed Afshin Samaei
- Department of Neurology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Ali Rashidy-Pour
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran
- Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
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Laguna-Abreu MTC, Germano C, Moreira AC, Antunes-Rodrigues J, Elias L, Castro M. Changes in prolactin secretion in the short- and long-term after adrenalectomy. ACTA ACUST UNITED AC 2012; 56:244-9. [DOI: 10.1590/s0004-27302012000400005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 06/02/2012] [Indexed: 11/22/2022]
Abstract
OBJECTIVE: To evaluate the modulation of the hypothalamus-pituitary-adrenal axis (HPA) on prolactin secretion in rats after adrenalectomy (ADX). MATERIALS AND METHODS: Plasma corticosterone, ACTH, and prolactin concentrations were measured by radioimmunoassay in rats after bilateral ADX in the short- (3 hours and 1day) and long-term (3, 7, and 14 days). RESULTS: Animals that underwent ADX showed undetectable corticosterone levels and a triphasic ACTH response with a transient increase (3h), a decrease (1d), and further increase in the long-term after ADX. Sham animals showed a marked increase in corticosterone and ACTH levels three hours after surgery, with a decrease to basal levels thereafter. Plasma prolactin levels were not changed after ADX. CONCLUSION: There are different points of equilibrium in the HPA axis after the glucocorticoid negative feedback is removed. Prolactin plasma secretion is not altered in the short or long- term after ADX, suggesting that the peptidergic neurons essential for prolactin release are not activated after ADX.
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Washington IM, Van Hoosier G. Clinical Biochemistry and Hematology. THE LABORATORY RABBIT, GUINEA PIG, HAMSTER, AND OTHER RODENTS 2012. [PMCID: PMC7150282 DOI: 10.1016/b978-0-12-380920-9.00003-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
This chapter discusses the clinical biochemistry and hematology of the rabbit (Oryctolagus cuniculus), guinea pig (Cavia porcellus), hamster (Mesocricetus auratus), and other rodents, including the gerbil (Meriones unguiculatus), chinchilla (Chinchilla laniger), degu (Octodon degus), deer mouse (Peromyscus maniculatus), dormouse (Gliridae family), kangaroo rat (Dipodomys spp.), cotton rat (Sigmodon hispidus), and sand rat (Psammomys obesus). The chapter begins with a review of sample collection and preparation, and a description of commonly measured parameters and analytical techniques. The reference values, sources of variation, and unique characteristics are then presented for each species, as available. Many variables affect the parameters of clinical biochemistry and hematology including methods of sample collection and preparation, equipment, reagents, and methods of analysis, as well as the age, sex, breed, and environment of the animals being sampled. Values obtained from a clinical case are usually compared with reference values that are either produced in the same laboratory or in a similar group of animals, or cited in the literature. Optimal sites for blood collection vary between laboratory animals and are described in this chapter for each species for which information is available. Total blood volume of the rabbit is discussed in the Hematology section of the chapter. The rabbit is recognized as a valuable model for human disturbances in lipid metabolism, such as the metabolic syndrome and hypercholesterolemia leading to atherosclerosis. Hematology is the study of blood and blood-forming organs, including the diagnosis, treatment, and prevention of diseases of the blood, bone marrow, and immunologic, hemostatic, and vascular systems. Hematologic analysis is often used for the diagnosis and treatment of animal diseases.
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Zhang P, Liu L, Xie CJ, Wang KH, Gao LZ, Ju G. Excitatory and inhibitory effects of prolactin release activated by nerve stimulation in rat anterior pituitary. Reprod Biol Endocrinol 2009; 7:154. [PMID: 20042121 PMCID: PMC2804610 DOI: 10.1186/1477-7827-7-154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Accepted: 12/31/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A series of studies showed the presence of substantial amount of nerve fibers and their close relationship with the anterior pituitary gland cells. Our previous studies have suggested that aside from the classical theory of humoral regulation, the rat anterior pituitary has direct neural regulation on adrenocorticotropic hormone release. In rat anterior pituitary, typical synapses are found on every type of the hormone-secreting cells, many on lactotrophs. The present study was aimed at investigating the physiological significance of this synaptic relationship on prolactin release. METHODS The anterior pituitary of rat was sliced and stimulated with electrical field in a self-designed perfusion chamber. The perfusate was continuously collected in aliquots and measured by radioimmunoassay for prolactin levels. After statistic analysis, differences of prolactin concentrations within and between groups were outlined. RESULTS The results showed that stimulation at frequency of 2 Hz caused a quick enhancement of prolactin release, when stimulated at 10 Hz, prolactin release was found to be inhibited which came slower and lasted longer. The effect of nerve stimulation on prolactin release is diphasic and frequency dependent. CONCLUSIONS The present in vitro study offers the first physiological evidence that stimulation of nerve fibers can affect prolactin release in rat anterior pituitary. Low frequency stimulation enhances prolactin release and high frequency mainly inhibits it.
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Affiliation(s)
- Ping Zhang
- Institute of Neurosciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ling Liu
- Institute of Neurosciences, the Fourth Military Medical University, Xi'an, China
| | - Cong-Jun Xie
- Institute of Neurosciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Kai-Hu Wang
- School of Foreign Languages, Shanghai Jiao Tong University, Shanghai, China
| | - Li-Zhi Gao
- Institute of Neurosciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Gong Ju
- Institute of Neurosciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Institute of Neurosciences, the Fourth Military Medical University, Xi'an, China
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Insana SP, Wilson JH. Social buffering in rats: prolactin attenuation of active interaction. Psychol Rep 2008; 103:77-87. [PMID: 18982939 DOI: 10.2466/pr0.103.1.77-87] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Stress may result when the present environment is interpreted as threatening, and stress is known to increase the prolactin-secretory response. In the present study, rats (N=83) were exposed to a conditioned-fear paradigm (environment paired with footshock), and on testing day, rats were exposed to the experimental chamber without shock while alone (Alone n=16), with an object (Object n=17), with a euthanized conspecific (Euthanized n=16), or with a social partner (Social n=19). The control group (Control n=15) was exposed to the experimental chamber but was never shocked. The Control group had significantly lower levels of prolactin than the Alone, Object, and Euthanized groups; however, the Control group's levels of prolactin were not significantly different than that of the Social group, which was significantly lower than that for the Alone group. Social interaction decreased fear independent of the distraction provided by a stimulus in the chamber. Active touch appeared to be crucial for social buffering to occur.
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Nováková M, Palme R, Kutalová H, Janský L, Frynta D. The effects of sex, age and commensal way of life on levels of fecal glucocorticoid metabolites in spiny mice (Acomys cahirinus). Physiol Behav 2008; 95:187-93. [DOI: 10.1016/j.physbeh.2008.05.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 05/20/2008] [Accepted: 05/28/2008] [Indexed: 10/22/2022]
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Emiliano ABF, Fudge JL. From galactorrhea to osteopenia: rethinking serotonin-prolactin interactions. Neuropsychopharmacology 2004; 29:833-46. [PMID: 14997175 DOI: 10.1038/sj.npp.1300412] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The widespread use of the selective serotonin reuptake inhibitors (SSRIs) has been accompanied by numerous reports describing a potential association with hyperprolactinemia. Antipsychotics are commonly known to elevate serum prolactin (PRL) through blockade of dopamine receptors in the pituitary. However, there is little awareness of the mechanisms by which SSRIs stimulate PRL release. Hyperprolactinemia may result in overt symptoms such as galactorrhea, which may be accompanied by impaired fertility. Long-term clinical sequelae include decreased bone density and the possibility of an increased risk of breast cancer. Through literature review, we explore the possible pathways involved in serotonin-induced PRL release. While the classic mechanism of antipsychotic-induced hyperprolactinemia directly involves dopamine cells in the tuberoinfundibular pathway, SSRIs may act on this system indirectly through GABAergic neurons. Alternate pathways involve serotonin stimulation of vasoactive intestinal peptide (VIP) and oxytocin (OT) release. We conclude with a comprehensive review of clinical sequelae associated with hyperprolactinemia, and the potential role of SSRIs in this phenomenon.
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Affiliation(s)
- Ana B F Emiliano
- Department of Psychiatry, University of Rochester Medical Center, Rochester, NY, USA.
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Pohorecky LA, Baumann MH, Benjamin D. Effects of chronic social stress on neuroendocrine responsiveness to challenge with ethanol, dexamethasone and corticotropin-releasing hormone. Neuroendocrinology 2004; 80:332-42. [PMID: 15692218 DOI: 10.1159/000083682] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2004] [Accepted: 11/25/2004] [Indexed: 11/19/2022]
Abstract
Neuroendocrine and behavioral profiles of group-housed rodents differ from those of singly-housed ones. Subordinate rats have elevated plasma corticosterone (CORT) concentration and impaired activity of the hypothalamic-pituitary-adrenal (HPA) axis compared to dominant cagemates. However, little is known about the effects of social hierarchy on other stress-related hormones. We examined plasma prolactin (PRL) and CORT responses to saline and ethanol (EtOH) injections, and 1 month later to dexamethasone (DEX) and corticotropin-releasing hormone (CRH) challenges of group- (triad) and single-housed male rats over a period of 225 days. Social status was determined from behaviors displayed upon initial triad housing. Subordinate rats had lower basal PRL and higher CORT compared to dominant rats. The injection of EtOH (1.25 g/kg) depressed PRL and elevated CORT levels significantly more than the saline injection only in dominant and singly-housed rats. DEX increased PRL levels, most strikingly in dominant rats, and suppressed CORT only in dominant rats. After CRH challenge, plasma CORT increased in all groups, subdominant and subordinate rats displaying blunted responses. Our data demonstrate that social rank and housing conditions affect plasma PRL and CORT concentrations, and modify responses to EtOH, possibly reflecting impairments of HPA axis regulation in socially-housed rats.
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Affiliation(s)
- Larissa A Pohorecky
- Center of Alcohol Studies, Rutgers University, 607 Alison Road, Piscataway, NJ 08855-8001, USA.
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Freeman ME, Kanyicska B, Lerant A, Nagy G. Prolactin: structure, function, and regulation of secretion. Physiol Rev 2000; 80:1523-631. [PMID: 11015620 DOI: 10.1152/physrev.2000.80.4.1523] [Citation(s) in RCA: 1463] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Prolactin is a protein hormone of the anterior pituitary gland that was originally named for its ability to promote lactation in response to the suckling stimulus of hungry young mammals. We now know that prolactin is not as simple as originally described. Indeed, chemically, prolactin appears in a multiplicity of posttranslational forms ranging from size variants to chemical modifications such as phosphorylation or glycosylation. It is not only synthesized in the pituitary gland, as originally described, but also within the central nervous system, the immune system, the uterus and its associated tissues of conception, and even the mammary gland itself. Moreover, its biological actions are not limited solely to reproduction because it has been shown to control a variety of behaviors and even play a role in homeostasis. Prolactin-releasing stimuli not only include the nursing stimulus, but light, audition, olfaction, and stress can serve a stimulatory role. Finally, although it is well known that dopamine of hypothalamic origin provides inhibitory control over the secretion of prolactin, other factors within the brain, pituitary gland, and peripheral organs have been shown to inhibit or stimulate prolactin secretion as well. It is the purpose of this review to provide a comprehensive survey of our current understanding of prolactin's function and its regulation and to expose some of the controversies still existing.
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Affiliation(s)
- M E Freeman
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306-4340, USA.
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Recio J, Pévet P, Masson-Pévet M. Regulation of melatonin receptors in the pars tuberalis of Syrian hamsters transferred from long to short photoperiod: implication of melatonin and testosterone. J Neuroendocrinol 1998; 10:303-8. [PMID: 9630401 DOI: 10.1046/j.1365-2826.1998.00208.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The exposure of long day seasonal breeders to a short photoperiod (SP) induces both sexual quiescence and a decrease in pars tuberalis (PT) melatonin receptor density. Therefore, we studied the respective roles of melatonin and testosterone on the regulation of PT melatonin receptors in Syrian hamsters transferred from long photoperiod (LP) to SP. Compared with intact sexually active animals in LP, the density of melatonin receptors was not affected by the absence of melatonin after removal of the pineal gland from animals kept in either SP or LP. In contrast, the presence of a long melatonin peak in the blood which induces gonadal atrophy induced a significant decrease in binding capacity. The SP-induced decrease in PT melatonin receptor density was also observed in castrated animals showing that it was directly regulated by melatonin, independently of circulating testosterone concentrations. However, the absence of testosterone induced an increased binding in LP, while increasing blood testosterone concentration after implantation of one testosterone-filled silastic tube resulted in a decrease in binding both in LP-and in SP-animals. These results indicate that testosterone induces a photoperiod-independent decrease in PT melatonin receptor density. In summary, these results show that both melatonin and testosterone have negative regulatory effects on the density of PT melatonin receptors.
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Affiliation(s)
- J Recio
- Neurobiologie des Fonctions Rythmiques et Saisonnières, Université Louis Pasteur, Strasbourg, France
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Martinez M, Calvo-Torrent A, Pico-Alfonso MA. Social defeat and subordination as models of social stress in laboratory rodents: A review. Aggress Behav 1998. [DOI: 10.1002/(sici)1098-2337(1998)24:4<241::aid-ab1>3.0.co;2-m] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Castro WL, Matt KS. The importance of social condition in the hormonal and behavioral responses to an acute social stressor in the male Siberian dwarf hamster (Phodopus sungorus). Horm Behav 1997; 32:209-16. [PMID: 9454672 DOI: 10.1006/hbeh.1997.1423] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Social condition is an important factor in determining the behavioral and hormonal responses to a social stressor in the Siberian dwarf hamster (Phodopus sungorus). We predict that males housed with a female or a family (female and pups) will show an increase in the magnitude of the behavioral and hormonal responses to a male intruder compared to those of individually housed males. Three treatment groups were studied: individually housed males that had been previously group-housed in same-sex colonies (males, n = 10), males housed with a female (male + female, n = 9), and males housed with their female and pups (male + family, n = 12). Males were monitored for aggressive behavior toward an intruder male for 10 min. Blood samples were taken at baseline and after the encounter. Male + female and male + family groups spent more time in aggressive behavior (P < 0.05), such as attacking (P < 0.05) and fighting (P < 0.05), than did individually housed males. These same groups showed significant increases in plasma cortisol after the encounter (P < 0.01) whereas there were no significant increases in plasma cortisol in solitary males. All groups showed significantly lower levels of plasma testosterone (male, P < 0.001, male + female, P < 0.05; male + family, P < 0.01) whereas a significant increase in prolactin occurred only in the male + family group (P < 0.05). There was a significant positive correlation between postencounter cortisol levels and total number of minutes spent in aggressive behavior (P < 0.05). These results demonstrate that the introduction of a novel intruder male results in an activation of the hypothalamic-pituitary-adrenocortical axis and a suppression of the reproductive axis. Furthermore, pairing of a male with a female alters the behavioral and hormonal responses to an intruder male.
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Affiliation(s)
- W L Castro
- Department of Zoology, Arizona State University, Tempe 85287, USA
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