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Life (Basel, Switzerland) Jul 2022This review demonstrates current literature on pineal gland physiology, pathology, and animal model experiments to concisely explore future needs in research development... (Review)
Review
This review demonstrates current literature on pineal gland physiology, pathology, and animal model experiments to concisely explore future needs in research development with respect to pineal gland function and neuro-regenerative properties. The pineal gland plays an integral role in sleep and recovery by promoting physiologic circadian rhythms via production and release of melatonin. Yet, the current literature shows that the pineal gland has neuroprotective effects that modulate both peripheral and central nerve injuries through several direct and indirect mechanisms, such as angiogenesis and induction of growth factors and anti-inflammatory mediators. Animal models have also shown correlations between pineal gland function and metabolic homeostasis. Studies have shown that a functional pineal gland is essential in preventing and slowing the progression of certain diseases such as diabetes, osteoporosis, vertebral osteoarthritis, and neurodegenerative processes. Lastly, the array of cell culturing methods and animal models that can be used to further develop the study of pineal gland function and nervous system injury were reviewed.
PubMed: 35888145
DOI: 10.3390/life12071057 -
Animals : An Open Access Journal From... Feb 2024Melatonin is a hormone mainly produced by the pineal gland in the absence of light stimuli. The light, in fact, hits the retina, which sends a signal to the... (Review)
Review
Melatonin is a hormone mainly produced by the pineal gland in the absence of light stimuli. The light, in fact, hits the retina, which sends a signal to the suprachiasmatic nucleus, which inhibits the synthesis of the hormone by the epiphysis. Mostly by interacting with MT1/MT2 membrane receptors, melatonin performs various physiological actions, among which are its regulation of the sleep-wake cycle and its control of the immune system. One of its best known functions is its non-enzymatic antioxidant action, which is independent from binding with receptors and occurs by electron donation. The hormone is also an indicator of the photoperiod in seasonally reproducing mammals, which are divided into long-day and short-day breeders according to the time of year in which they are sexually active and fertile. It is known that melatonin acts at the hypothalamic-pituitary-gonadal axis level in many species. In particular, it inhibits the hypothalamic release of GnRH, with a consequent alteration of FSH and LH levels. The present paper mainly aims to review the ovarian effect of melatonin.
PubMed: 38396612
DOI: 10.3390/ani14040644 -
Surgical Neurology International 2018Pineal cysts are benign lesions of the pineal gland without a clear etiology. Currently, different approaches are described to deal with pineal region lesions and...
BACKGROUND
Pineal cysts are benign lesions of the pineal gland without a clear etiology. Currently, different approaches are described to deal with pineal region lesions and particularly with pineal cysts. Although endoscopic procedures are becoming more frequent, some technical advantages of the microsurgical resection still make it the gold standard. Our aim was to demonstrate the efficiency and safety of our microsurgical technique into deep brain territories under the principle "simple, clean, and preserving the normal anatomy." Herein, we present an unedited microneurosurgery of a histologically confirmed large benign pineal cyst.
CASE DESCRIPTION
A patient with antidepressant medication, psychotic attacks, memory problems, and progressively intense headache along the last months underwent sitting praying position and supracerebellar infratentorial paramedian approach. Under high magnification, the pineal region was accessed over the right cerebellar hemisphere. A lateral focused opening of the quadrigeminal cistern and the posterior wall of the pineal cyst were followed by partial aspiration of the cystic content. Small vessels running around the cyst were carefully dissected, and few of those attached to the wall were coagulated and cut. After careful devascularization of the lesion, the cyst was detached and pulled out using soft and continuous traction with a long ring microforceps in the right hand and thumb-controlled suction tube in the left one. The final steps included meticulous attention to any bleeding securing complete hemostasis of the surgical site. The postoperative course was uneventful and the patient improved dramatically with resolution of the headache and progressive reduction of psychiatric medication.
CONCLUSION
This unedited video offers all detailed aspects that a neurosurgeon as the senior author JH considers essential when performing an efficient and safe pineal cyst surgery.
VIDEOLINK
http://surgicalneurologyint.com/videogallery/pineal-cyst/.
PubMed: 30687572
DOI: 10.4103/sni.sni_356_18 -
Ochsner Journal 2019The pineal gland, a small, pinecone-shaped organ deep within the brain, is responsible for producing melatonin. The gland consists of pineal parenchymal cells and glial... (Review)
Review
The pineal gland, a small, pinecone-shaped organ deep within the brain, is responsible for producing melatonin. The gland consists of pineal parenchymal cells and glial cells that can form neoplasms. Pineal region neoplasms can also arise from germ cells and adjacent structures. This review focuses on detection of serum and cerebrospinal fluid (CSF) biomarkers of germ cell tumors and pineal parenchymal cell tumors, as these types comprise most neoplasms specific to the pineal region. For this review, we searched PubMed using the following keywords: biomarkers, germ cell tumor, germinoma, melatonin, pineal, pineal gland, pineal neoplasm, pinealoma, pineal parenchymal cell tumor, pineal region, and pineal tumor. We limited our search to full-text English articles and identified other relevant sources from the reference lists of identified articles. Serum and CSF biomarker assays have a role in cases of suspected pineal germ cell or parenchymal neoplasms. Biomarkers including alpha-fetoprotein, beta-human chorionic gonadotropin, and placental alkaline phosphatase inform diagnosis and treatment and are important for monitoring germ cell tumor response to treatment. No biomarkers are currently available that inform diagnosis or treatment of pineal parenchymal tumors, although melatonin assays may have a role in monitoring response to treatment. Serum and CSF biomarkers in conjunction with clinical and radiographic evidence of a pineal region mass can inform the decision whether to undertake stereotactic biopsy or surgical excision or whether to proceed straight to medical treatment.
PubMed: 30983898
DOI: 10.31486/toj.18.0110 -
Frontiers in Bioscience (Elite Edition) Jan 2021Melatonin, a hormone which is primarily released by the pineal gland, has a wide range of actions in the female reproductive tract. While the melatonin receptor subtype,... (Review)
Review
Melatonin, a hormone which is primarily released by the pineal gland, has a wide range of actions in the female reproductive tract. While the melatonin receptor subtype, MT3, has been identified in amphibian animals and birds, in humans and other mammals, melatonin acts through, MT1 and MT2 receptor subtypes which are expressed in human ovaries. The rhythmic release of melatonin starts at puberty and continues throughout fertile female life, affecting and regulating diverse ovarian functions. Here, we discuss the importance of melatonin in regulating folliculogenesis, oocyte quality, ovulation and luteal function, sex steroid receptor gene expression, ovarian steroidogenesis including the production and steroidogenic enzyme activities in the egg and thecal cells. Melatonin improves the egg quality and increases the chance of success of in vitro fertilization (IVF). In view of such extensive actions, melatonin is central to the fertility in females. The objective of this review is to recapitulate the current understanding of the role of melatonin and its receptors.
Topics: Animals; Female; Humans; Melatonin; Ovary; Receptor, Melatonin, MT2; Receptors, Melatonin
PubMed: 33048779
DOI: 10.2741/875 -
Biomedicine & Pharmacotherapy =... Oct 2023Septic cardiomyopathy (SCM) is a common complication of sepsis contributing to high mortality rates. Its pathophysiology involves complex factors, including inflammatory... (Review)
Review
Septic cardiomyopathy (SCM) is a common complication of sepsis contributing to high mortality rates. Its pathophysiology involves complex factors, including inflammatory cytokines, mitochondrial dysfunction, oxidative stress, and immune dysregulation. Despite extensive research, no effective pharmacological agent has been established for sepsis-induced cardiomyopathy. Melatonin, a hormone with diverse functions in the body, has emerged as a potential agent for SCM through its anti-oxidant, anti-inflammatory, anti-apoptotic, and cardioprotective roles. Through various molecular levels of its mechanism of action, it counterattacks the adverse event of sepsis. Experimental studies have mentioned that melatonin protects against many cardiovascular diseases and exerts preventive effects on SCM. Moreover, melatonin has been investigated in combination with other drugs such as antibiotics, resveratrol, and anti-oxidants showing synergistic effects in reducing inflammation, anti-oxidant, and improving cardiac function. While preclinical studies have demonstrated positive results, clinical trials are required to establish the optimal dosage, route of administration, and treatment duration for melatonin in SCM. Its safety profile, low toxicity, and natural occurrence in the human body provide a favorable basis for its clinical use. This review aims to provide an overview of the current evidence of the use of melatonin in sepsis-induced cardiomyopathy (SICM). Melatonin appears to be promising as a possible treatment for sepsis-induced cardiomyopathy and demands further investigation.
Topics: Humans; Melatonin; Antioxidants; Cardiomyopathies; Cardiovascular Diseases; Sepsis
PubMed: 37619482
DOI: 10.1016/j.biopha.2023.115305 -
ASN Neuro 2022The circumventricular organs (CVOs) are unique areas within the central nervous system. They serve as a portal for the rest of the body and, as such, lack a blood-brain... (Review)
Review
The circumventricular organs (CVOs) are unique areas within the central nervous system. They serve as a portal for the rest of the body and, as such, lack a blood-brain barrier. Microglia are the primary resident immune cells of the brain parenchyma. Within the CVOs, microglial cells find themselves continuously challenged and stimulated by local and systemic stimuli, even under steady-state conditions. Therefore, CVO microglia in their typical state often resemble the activated microglial forms found elsewhere in the brain as they are responding to pathological conditions or other stressors. In this review, I focus on the dynamics of CVO microglia, using the pineal gland as a specific CVO example. Data related to microglia heterogeneity in both homeostatic and unhealthy environments are presented and discussed, including those recently generated by using advanced single-cell and single-nucleus technology. Finally, perspectives in the CVO microglia field are also included.Microglia in circumventricular organs (CVOs) continuously adapt to react differentially to the diverse challenges they face. Herein, I discuss microglia heterogeneity in CVOs, including pineal gland. Further studies are needed to better understand microglia dynamics in these unique brain areas. .
Topics: Microglia; Pineal Gland; Circumventricular Organs; Blood-Brain Barrier; Brain
PubMed: 36317305
DOI: 10.1177/17590914221135697 -
Encephalitis (Seoul, Korea) Apr 2023The suprachiasmatic nucleus (SCN) in the anterior hypothalamus is the major circadian pacemaker in humans. Melatonin is a key hormone secreted by the pineal gland in... (Review)
Review
The suprachiasmatic nucleus (SCN) in the anterior hypothalamus is the major circadian pacemaker in humans. Melatonin is a key hormone secreted by the pineal gland in response to darkness. Light-induced stimuli are transmitted along the retinohypothalamic tract to the SCN. Activation of the SCN inhibits the production of melatonin by the pineal gland through a complex neural pathway passing through the superior cervical ganglion. Accordingly, when light is unavailable, the pineal gland secretes melatonin. The circadian rhythm modulates sleep-wake cycles as well as many physiological functions of the endocrine system, including core body temperature, pulse rate, oxygen consumption, hormone levels, metabolism, and gastrointestinal function. In neurodegenerative disorders, the sleep-wake cycle is disrupted and circadian regulation is altered, which accelerates disease progression, further disrupting circadian regulation and setting up a vicious cycle. Melatonin plays a critical role in the regulation of circadian rhythms and is a multifunctional pleiotropic agent with broad neuroprotective effects in neurodegenerative disorders, viral or autoimmune diseases, and cancer. In this review, I discuss the neuroprotective functions of melatonin in circadian regulation and its roles in promoting anti-inflammatory activity, enhancing immune system functions, and preventing alterations in glucose metabolism and mitochondrial dysfunction in neurodegenerative disorders and autoimmune central nervous system diseases.
PubMed: 37469673
DOI: 10.47936/encephalitis.2022.00094 -
Current Neuropharmacology Mar 2022Melatonin, a vital hormone synthesized by the pineal gland, has been implicated in various physiological functions and circadian rhythm regulation. Its role in the... (Review)
Review
Melatonin, a vital hormone synthesized by the pineal gland, has been implicated in various physiological functions and circadian rhythm regulation. Its role in the protection against the non-ionizing electromagnetic field (EMF), known to disrupt the body's oxidative/anti-oxidative balance, has been called into question due to inconsistent results observed across studies. This review provides the current knowledge on the interwoven relationship between melatonin, EMF, and oxidative stress. Based on synthesized evidence, we present a model that best describes the mechanisms underlying the protective effects of melatonin against RF/ELF-EMF-induced oxidative stress. It has been observed that the free radical scavenger activity of melatonin can be enabled by reducing the radical pair singlet-triplet conversion rate and the concentration of the triplet products. Moreover, this review aims to highlight the potential therapeutic benefits of melatonin against the detrimental effects of EMF, in general, and electromagnetic hypersensitivity (EHS), in particular.
Topics: Circadian Rhythm; Electromagnetic Fields; Electromagnetic Radiation; Humans; Melatonin; Oxidative Stress; Pineal Gland
PubMed: 34635042
DOI: 10.2174/1570159X19666210609163946 -
Molecules (Basel, Switzerland) Aug 2018Melatonin, -acetyl-5-methoxytryptamine, is an indole mainly synthesized from tryptophan in the pineal gland and secreted exclusively during the night in all the animals... (Review)
Review
Melatonin, -acetyl-5-methoxytryptamine, is an indole mainly synthesized from tryptophan in the pineal gland and secreted exclusively during the night in all the animals reported to date. While the pineal gland is the major source responsible for this night rise, it is not at all the exclusive production site and many other tissues and organs produce melatonin as well. Likewise, melatonin is not restricted to vertebrates, as its presence has been reported in almost all the phyla from protozoa to mammals. Melatonin displays a large set of functions including adaptation to light: dark cycles, free radical scavenging ability, antioxidant enzyme modulation, immunomodulatory actions or differentiation⁻proliferation regulatory effects, among others. However, in addition to those important functions, this evolutionary 'ancient' molecule still hides further tools with important cellular implications. The major goal of the present review is to discuss the data and experiments that have addressed the relationship between the indole and glucose. Classically, the pineal gland and a pinealectomy were associated with glucose homeostasis even before melatonin was chemically isolated. Numerous reports have provided the molecular components underlying the regulatory actions of melatonin on insulin secretion in pancreatic beta-cells, mainly involving membrane receptors MTNR1A/B, which would be partially responsible for the circadian rhythmicity of insulin in the organism. More recently, a new line of evidence has shown that glucose transporters GLUT/SLC2A are linked to melatonin uptake and its cellular internalization. Beside its binding to membrane receptors, melatonin transportation into the cytoplasm, required for its free radical scavenging abilities, still generates a great deal of debate. Thus, GLUT transporters might constitute at least one of the keys to explain the relationship between glucose and melatonin. These and other potential mechanisms responsible for such interaction are also discussed here.
Topics: Animals; Biological Transport; Cell Membrane; Energy Metabolism; Glucose; Humans; Insulin; Melatonin; Pineal Gland; Protein Transport; Secretory Vesicles
PubMed: 30103453
DOI: 10.3390/molecules23081999