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Abstract
Oxytocin (OT) is a nonapeptide mainly produced in the supraoptic and paraventricular nuclei. OT in the brain and blood has extensive functions in both mental and physical activities. These functions are mediated by OT receptors (OTRs) that are distributed in a broad spectrum of tissues with dramatic sexual dimorphism. In both sexes, OT generally facilitates social cognition and behaviors, facilitates parental behavior and sexual activity and inhibits feeding and pain perception. However, there are significant differences in OT levels and distribution of OTRs in men from women. Thus, many OT functions in men are different from women, particularly in the reproduction. In men, the reproductive functions are relatively simple. In women, the reproductive functions involve menstrual cycle, pregnancy, parturition, lactation, and menopause. These functions make OT regulation of women's health and disease a unique topic of physiological and pathological studies. In menstruation, pre-ovulatory increase in OT secretion in the hypothalamus and the ovary can promote the secretion of gonadotropin-releasing hormone and facilitate ovulation. During pregnancy, increased OT synthesis and preterm release endow OT system the ability to promote maternal behavior and lactation. In parturition, cervix expansion-elicited pulse OT secretion and uterine OT release accelerate the expelling of fetus and reduce postpartum hemorrhage. During lactation, intermittent pulsatile OT secretion is necessary for the milk-ejection reflex and maternal behavior. Disorders in OT secretion can account for maternal depression and hypogalactia. In menopause, the reduction of OT secretion accounts for many menopausal symptoms and diseases. These issues are reviewed in this work.
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Affiliation(s)
- Ning Liu
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Haipeng Yang
- Neonatal Division of the Department of Pediatrics, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Liqun Han
- Department of Radiology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Mingxing Ma
- Department of Colorectal Cancer Surgery, Shengjing Hospital of China Medical University, Shenyang, China
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, China
- *Correspondence: Mingxing Ma,
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Wang P, Wang SC, Liu X, Jia S, Wang X, Li T, Yu J, Parpura V, Wang YF. Neural Functions of Hypothalamic Oxytocin and its Regulation. ASN Neuro 2022; 14:17590914221100706. [PMID: 35593066 PMCID: PMC9125079 DOI: 10.1177/17590914221100706] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Oxytocin (OT), a nonapeptide, has a variety of functions. Despite extensive studies on OT over past decades, our understanding of its neural functions and their regulation remains incomplete. OT is mainly produced in OT neurons in the supraoptic nucleus (SON), paraventricular nucleus (PVN) and accessory nuclei between the SON and PVN. OT exerts neuromodulatory effects in the brain and spinal cord. While magnocellular OT neurons in the SON and PVN mainly innervate the pituitary and forebrain regions, and parvocellular OT neurons in the PVN innervate brainstem and spinal cord, the two sets of OT neurons have close interactions histologically and functionally. OT expression occurs at early life to promote mental and physical development, while its subsequent decrease in expression in later life stage accompanies aging and diseases. Adaptive changes in this OT system, however, take place under different conditions and upon the maturation of OT release machinery. OT can modulate social recognition and behaviors, learning and memory, emotion, reward, and other higher brain functions. OT also regulates eating and drinking, sleep and wakefulness, nociception and analgesia, sexual behavior, parturition, lactation and other instinctive behaviors. OT regulates the autonomic nervous system, and somatic and specialized senses. Notably, OT can have different modulatory effects on the same function under different conditions. Such divergence may derive from different neural connections, OT receptor gene dimorphism and methylation, and complex interactions with other hormones. In this review, brain functions of OT and their underlying neural mechanisms as well as the perspectives of their clinical usage are presented.
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Affiliation(s)
- Ping Wang
- Department of Genetics, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Stephani C. Wang
- Division of Cardiology, Department of Medicine, University of California-Irvine, Irvine, California, USA
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
- Neuroscience Laboratory for Translational Medicine, School of Mental Health, Qiqihar Medical University, Qiqihar, China
| | - Jiawei Yu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
- Kerqin District Maternity & Child Healthcare Hospital, Tongliao, Inner Mongolia, China
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
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Lovick TA, Zangrossi H. Effect of Estrous Cycle on Behavior of Females in Rodent Tests of Anxiety. Front Psychiatry 2021; 12:711065. [PMID: 34531768 PMCID: PMC8438218 DOI: 10.3389/fpsyt.2021.711065] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 08/04/2021] [Indexed: 11/13/2022] Open
Abstract
Anxiety disorders are more prevalent in women than in men. In women the menstrual cycle introduces another variable; indeed, some conditions e.g., premenstrual syndrome, are menstrual cycle specific. Animal models of fear and anxiety, which form the basis for research into drug treatments, have been developed almost exclusively, using males. There remains a paucity of work using females and the available literature presents a confusing picture. One confound is the estrous cycle in females, which some authors consider, but many do not. Importantly, there are no accepted standardized criteria for defining cycle phase, which is important given the rapidly changing hormonal profile during the 4-day cycle of rodents. Moreover, since many behavioral tests that involve a learning component or that consider extinction of a previously acquired association require several days to complete; the outcome may depend on the phase of the cycle on the days of training as well as on test days. In this article we consider responsiveness of females compared to males in a number of commonly used behavioral tests of anxiety and fear that were developed in male rodents. We conclude that females perform in a qualitatively similar manner to males in most tests although there may be sex and strain differences in sensitivity. Tests based on unconditioned threatening stimuli are significantly influenced by estrous cycle phase with animals displaying increased responsiveness in the late diestrus phase of the cycle (similar to the premenstrual phase in women). Tests that utilize conditioned fear paradigms, which involve a learning component appear to be less impacted by the estrous cycle although sex and cycle-related differences in responding can still be detected. Ethologically-relevant tests appear to have more translational value in females. However, even when sex differences in behavior are not detected, the same outward behavioral response may be mediated by different brain mechanisms. In order to progress basic research in the field of female psychiatry and psychopharmacology, there is a pressing need to validate and standardize experimental protocols for using female animal models of anxiety-related states.
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Affiliation(s)
- Thelma A. Lovick
- Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Hélio Zangrossi
- Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, Brazil
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