Journal of Reproductive Endocrinology & Infertility

Description

Reproductive neuroendocrinology has entered a new era since the discovery of Gonadotropin-Inhibitory Hormone (GnIH) in 2000. Prior to this, researchers believed that only gonadotropin-releasing hormone, neurohormone, controlled reproduction. In subsequent studies, it was discovered that GnIH is a novel key neurohormone that prevents vertebrate reproduction. Through the GnIH receptor GPR147 on gonadotropins and GnRH neurons, GnIH prevents gonadotropin synthesis and release. GnIH also prevents reproductive neuroendocrine behavior and function. GnIH synthesis has also been shown to be altered and released as a result of neuroendocrine integration of internal and external factors. As a result, advances in reproductive neuroendocrinology have been made easier thanks to the discovery of GnIH. The development of reproductive neuroendocrinology as a result of the discovery of GnIH and the regulatory mechanisms underlying GnIH synthesis and release are the subject of this paper. Neurohormones, neuropeptides, and neurotransmitters that either enter the skin through the vasculature or skin nerves or are produced intracutaneously all have paracrine and autocrine effects on the skin. The effects of neurohormones on human skin physiology and disease are the focus of this review. In cutaneous neuroendocrinology, fundamental concepts, major unanswered questions, and translational research perspectives are discussed. Additionally, we argue that by putting a greater emphasis on research into the skin's neuroendocrine system, new dermatological treatments will be developed. Nonclassical, ancestral neurohormone functions can also be studied using model systems that are easily accessible and relevant to clinical practice, like the human skin and its appendages.

Neuroendocrine Mechanisms

Dermatologists, neuroendocrinologists, neuropharmacologists, and skin biologists all need to work together closely in this regard. Over the course of the past fifty years, significant progress has been made in the investigation of the neuroendocrine-endocrine-neural regulation of maternal behavior. The progress made during this period has been broken down into five stages in this mini-review. The neural basis of maternal behavior in relation to endocrine actions, the influence of developmental and experiential states on maternal care, the dynamic neuroplastic maternal brain, and genes and motherhood are all included in these stages. The discussion of future directions in the field of motherhood neurobiology/neuroendocrinology concludes the final section. To investigate the extent to which testosterone influences human psychological and behavioral processes, social neuroendocrinology researchers have developed pharmacological challenge paradigms over the course of the past two decades. The findings of the study are briefly summarized in the current paper, which also offers suggestions for future research into the neuroendocrine mechanisms of human behavior. In 1969, fifty years ago, the first issue of Hormones and Behavior was published. At the time, the majority of Behavioral Endocrinology methods were unavailable. Autoimmunity can be sparked by metals, as has been demonstrated. However, the underlying mechanisms of action have only been examined and clarified in a small number of studies. The immune system's potential interactions with metal ions, particularly heavy metals, have been the focus of recent research. Metals, according to research, may stoke or accelerate human autoimmunity. Metal-induced inflammation may disrupt the hypothalamic-pituitary-adrenal axis, causing fatigue and other non-specific autoimmune diseases.

Over the course of the past five decades, techniques have been developed that make it possible to chemo genetically and ontogenetically alter the activity of particular neuronal populations, measure hormones in relatively small volumes of biological samples, pinpoint the regions of the brain where steroids cause sexual behavior, characterize and quantify gene expression that is correlated with behavior expression, and specifically alter this expression. There are some drawbacks, despite the fact that this technological development has significantly altered the field and improved our comprehension of endocrine behavior controls in general. Methodological requirements were slightly relaxed as a result of the facilitation of scientific investigations. Complex techniques provided as ready-to-use kits are utilized without precise knowledge of the techniques' limitations, and crucial controls are no longer carried out on a regular basis. The most important of these novel approaches, their potential drawbacks, and how they altered our understanding of how hormones regulate behavior are the focus of this section. Thankfully, the scientific method is self-correcting. The problems have been found, and possible solutions have been suggested. There will undoubtedly be many exciting discoveries in behavioral neuroendocrinology in the coming decades. Understanding the fundamental mechanisms of physiology and pathology still relies heavily on animal models. New therapeutic targets and neuroendocrinology principles that can be translated are revealed by these insights. Autoimmunity can be sparked by metals, as has been demonstrated. However, the underlying mechanisms of action have only been examined and clarified in a small number of studies. The immune system's potential interactions with metal ions, particularly heavy metals, have been the focus of recent research. Metals, according to research, may stoke or accelerate human autoimmunity. Metal-induced inflammation may disrupt the Hypothalamic-Pituitary-Adrenal (HPA) axis, causing fatigue and other non-specific autoimmune diseases. Autoimmunity can be sparked by metals, as has been demonstrated. However, the underlying mechanisms of action have only been examined and clarified in a small number of studies. The immune system's potential interactions with metal ions, particularly heavy metals, have been the focus of recent research. Metals, according to research, may stoke or accelerate human autoimmunity. Metal-induced inflammation may disrupt the hypothalamic-pituitary-adrenal axis, causing fatigue and other non-specific autoimmune diseases.

Mitochondrial Activity

The hypothalamic neuroendocrine cells, in particular, present a challenge for research because of their dynamic and complex nature. All through the development of vertebrates, the hypothalamic neuroendocrine frameworks, which are vital for endurance and proliferation, are profoundly preserved. They have control over stress, electrolyte balance, reproduction, growth and body composition, metabolism, and stress it. The results of a lot of research have led to new understandings of their roles. Domestic sheep were required for many of these discoveries. As a model for human neuroendocrinology, the hypothalamic neuroendocrine systems of sheep have been studied for decades. This chapter aims to discuss some significant biomedical advancement made possible by sheep research. As a neuroendocrine model, sheep's advantages and disadvantages will be discussed. Sheep are required for allowing manipulations that cannot be performed on human subjects and for isolating physiologic variables in order to gain insight into neuroendocrinology and the pathologies associated with it, despite the fact that no animal model can accurately replicate a human condition. The human hair follicle, or HF for short, is a cyclical organ that is particularly sensitive to hormones. Numerous neurohormones, neuropeptides, and neurotransmitters that control HF growth, pigmentation, remodeling, immune status, stem cell biology, and energy metabolism also come from it and target it. Indeed, organ-cultured human scalp HFs can identify "novel" clinically relevant functions of major neuromediators. Relevantly, the findings demonstrate that: i) Thyrotropin-Releasing Hormone (TRH) encourages hair growth and pigmentation; ii) Thyrotropin and TRH are powerful promoters of mitochondrial activity and regulators of keratin expression; and (iii) prolactin's function as a regulator of epithelial stem cells. As a result, insights from HF neuroendocrinology go far beyond dermatoendocrinology and hair growth. New therapeutic targets and neuroendocrinology principles that can be translated are revealed by these insights.

Numerous metals also contribute to their toxic effects through the production of free radicals, the disruption of cell membranes, or the inhibition of enzymes. Around the world, metal pollution is getting worse. As a result, it is absolutely necessary to conduct research into the role that metals play in autoimmunity and neuroendocrine disorders, as well as their effects on the brain and immune system as they develop and genetic susceptibility. These studies may result in effective preventive measures and improved therapeutic approaches. In this review, we have retrieved and discussed studies that examined how immune and endocrine pathways were affected by metal toxicity. The goal of this review is to make people aware of how neuroendocrine and autoimmune disorders start and progress with metals. Bargmann–Scharrer discovered "neurosecretion" in the first half of the 20th century, which has since grown into the scientific field of neuroendocrinology. The discovery of novel neurohormones like neuropeptides and neurosteroids is crucial to the development of neuroendocrinology. Our research over the past two decades has significantly expanded this field of study and opened up new avenues for neuroendocrinology research by discovering novel neuropeptides and neurosteroids in vertebrates. Since GnRH was discovered in mammals at the beginning of the 1970s, it has been widely believed that GnRH is the only hypothalamic neuropeptide in vertebrates that regulates gonadotropin release. GnIH, a novel hypothalamic neuropeptide that actively inhibits quail gonadotropin release, was discovered by us in 2000. It now appears that GnIH is highly conserved across vertebrates, including humans, and that, in addition to controlling reproduction, it also plays a number of behavioral and physiological roles. This opens up a huge field of study for researchers in many different fields. This summary provides an overview of the development of neuroendocrinology and the discovery of GnIH. In order to ascertain how neuroendocrine behavioral regulatory mechanisms function in natural settings, how they evolved, and ultimately how they can be applied to humans, it is essential to investigate them in a wide range of vertebrate species.