The Pineal Gland and Melatonin

• Hormones coordinate bodily functions by transmitting messages through the blood to organs and tissues.
• They act on target organs, instructing the body on what actions to perform and when.
• Endocrine glands secrete hormones, which are potent even in small amounts, leading to low circulating levels.
• Endocrinology studies the endocrine glands' structure and function, diagnosing and treating related disorders.
• Glands produce and release hormones that target specific things in the body.
• The pineal gland is a small gland present at the roof of the third ventricle attached to the surface by a short stalk composed of nerves.

Pineal Gland

• Cone-shaped gland located deep in the brain that manages the sleep cycle
• Releases melatonin, inducing sleepiness
• Develops from the embryonic neuroectoderm
• Consists of modified neurons known as pinacocytes
• Pinacocytes produce melatonin and release it directly into the cerebrospinal fluid, which then transports it into the bloodstream.
• Tiny, cone-shaped gland, approximately 0.8 cm long and weighs about 0.1 grams in adults.
• Receives light-dark cycle information from the eyes and secretes melatonin accordingly
• Elevated levels at night and low levels during the day
• While non-essential, lack of melatonin because of no pineal gland can cause challenging time with sleeping patterns and other physiologic functions related to the circadian rhythm

Hormones of the Pineal Gland: Melatonin

• Melatonin is regulated by daylight and darkness
• Highest level occurs at midnight, and the lowest occurs around midday
• Influences the hypothalamus to coordinate circadian and diurnal rhythms
• Affects the synthesis of gonadotropins, inhibiting the growth and development of sex organs
• May help synchronize circadian rhythms, following a 24-hour cycle primarily responding to light and dark changes
• Release is highest in darkness, decreasing with light exposure
• Often referred to as a "sleep hormone"
• While not essential for sleeping, one sleeps better when one has the highest levels of melatonin in the body
• Research indicates it helps regulate menstrual cycles
• Potentially protects against neurodegeneration as seen in conditions like Alzheimer's and Parkinson's disease

Disease Conditions and Disorders Affecting the Pineal Gland

• Pineal gland tumors can affect the pineal gland’s function and ability to release melatonin
• Injuries that affect the pineal gland can affect the pineal gland’s function and ability to release melatonin
• Pineal gland calcification can affect the pineal gland’s function and ability to release melatonin
• Depression can affect the pineal gland’s function and ability to release melatonin
• Mood swings can affect the pineal gland’s function and ability to release melatonin
• Pineal gland tumors are rare and more common in children and adults under 40
• Tumors can be non-cancerous but cause problems by pressing against the brain, blocking cerebrospinal fluid flow
• This blockage raises pressure inside the skull, requiring treatment
• Pinealectomy, surgical removal of the pineal gland, is rare but occurs
• Damage to the pineal gland can cause it to work improperly.
• Traumatic brain injury (TBI) can cause damage to the pineal gland
• Approximately 30% to 50% of people who experience a traumatic brain injury (TBI) have issues with at least one endocrine gland in their brain, which includes the pineal gland and pituitary gland.
• Calcification is common, especially with age, where calcium builds up in the tissue
• Excessive calcification can prevent proper function
• Higher degrees of calcification has been loosly linked with Alzheimer's and some migraine and cluster headaches

Signs and Symptoms of Pineal Gland Problems

• Seizures occur if one has a pineal gland tumor, which is rare
• Memory issues occur if one has a pineal gland tumor, which is rare
• Headaches occur if one has a pineal gland tumor, which is rare
• Nausea and vomiting occur if one has a pineal gland tumor, which is rare
• Vision changes occur if one has a pineal gland tumor, which is rare

Diagnosis/Common Tests to Check the Health of the Pineal Gland

• MRI (magnetic resonance imaging) or CT (computed tomography) scans are used to look at the pineal gland
• Providers use these imaging tests to help determine if one has a pineal tumour or cyst.
• X-rays are used to check for pineal gland calcification
• Blood tests are used to check melatonin levels

Treatment of Pineal Gland Conditions/Disorders

• Surgery to remove tumors, but difficult and not common
• Pinealectomy, the surgical removal of the entire pineal gland, is sometimes performed
• Radiation therapy uses strong energy beams to destroy cancer cells
• Chemotherapy uses drugs to destroy cancer cells
• Melatonin supplements may be prescribed for conditions causing low melatonin secretion

Additional Facts

• The pineal gland is also called the “third eye
• The pineal gland has commonly been called the mysterious organ
• It is located deep in the centre of the brain and its connection to light via the circadian rhythm and melatonin secretion
• In certain forms of Hinduism and Tantric Buddhism, they believe Chakras, specifically the third eye chakra, is linked to the pineal gland

Hypothalamus Gland

• Located below the thalamus and above the pituitary gland, directly above the brainstem
• Controls the endocrine system using information from the nervous system
• Maintains the body’s internal balance known as homeostasis
• Receives messages from nerve cells in the brain and body, responding to internal and external signals
• Main function is to react to messages to keep the body in a stable state or internal balance
• Helps manage heart rate
• Helps manage body temperature
• Helps manage blood pressure
• Helps manage fluid and electrolyte balance, including (Hunger and thirst, Appetite and body weight)
• Helps manage sense of fullness when eating
• Helps manage glandular secretions of the stomach and intestines
• Helps manage the production of substances that influence the pituitary gland to release hormones
• Helps manage sleep cycles
• Helps manage mood
• Helps manage sex drive
• Helps manage sleep
• Performs its "body balancing" jobs either by directly influencing the autonomic nervous system or by managing hormones.
• Receives information from nearly all parts of the nervous system
• Considered the link between the nervous system and the endocrine system
• Attached to the pituitary gland by the infundibulum, connecting the endocrine and nervous systems
• Secretes about nine different hormones, with seven regulating the pituitary gland
• Hormones are termed inhibiting or releasing hormones

Hormones of the Hypothalamus

• Secretes neurohormones to start and stop pituitary hormone secretion
• Sends releasing hormones to the anterior and posterior pituitary to signal hormone release

Anterior Pituitary

• Hypothalamus sends releasing hormones to tell the anterior pituitary to release (secrete) its hormones
• Hormones released by the hypothalamus to the anterior pituitary, the hormone the pituitary releases and what it does

Posterior Pituitary

• Hypothalamus makes two hormones but stores them in the posterior pituitary.
• When these hormones are needed, the hypothalamus sends a signal to the posterior pituitary to release them into the bloodstream.
• Oxytocin assists in birthing (uterine muscle contraction) and lactation (breast milk release)
• It plays a role also in human bonding, sexual arousal, trust, recognition, sleep cycle and feelings of well-being
• Vasopressin (antidiuretic hormone/ADH) regulates body water/urine volume and blood pressure
• Dopamine is the “feel-good” hormone
• It gives you a sense of pleasure and the motivation to do something when you are feeling pleasure
• Dopamine signals the pituitary to stop releasing prolactin
• Somatostatin prevents the secretion of several other hormones, including growth hormone, thyroid-stimulating hormone, cholecystokinin, and insulin
• All these hormones control the production of somatostatin.
• It inhibits the release of thyroid-stimulating hormone (TSH) and growth hormone (GH)
• Corrects any imbalances in body temperature, stress, and daily bodily rhythms
• Anti-diuretic hormone (Vasopressin) regulates water levels and influences blood volume and blood pressure
• It increases water absorption into the blood by the kidneys
• Corticotropin-releasing hormone (CRH) acts on the pituitary gland, causing the release of hormones in response to stress
• CRH sends a message to the anterior pituitary gland to stimulate the adrenal glands to release corticosteroids, which help regulate metabolism and immune response
• Oxytocin is involved in a variety of processes, such as orgasm, the ability to trust, body temperature, sleep cycles, and the release of breast milk
• It influences sexual and social behaviour
• Gonadotropin-Releasing Hormone (GnRH) stimulates the anterior pituitary to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which work together to ensure the normal functioning of the ovaries and testes
• It stimulates the pituitary to release hormones that influence the development of reproductive system structures
• Growth Hormone-Releasing Hormone (GHRH) or growth hormone-inhibiting hormone (GHIH) (also known as somatostatin): GHRH prompts the anterior pituitary to release growth hormone (GH); GHIH has the opposite effect
• In children, GH is essential to maintaining a healthy body composition
• In adults, it aids healthy bone and muscle mass and affects fat distribution
• Thyrotropin-Releasing Hormone (TRH) triggers the release of thyroid-stimulating hormone (TSH), which stimulates release of thyroid hormones that regulate metabolism, energy, and growth and development
• Prolactin-releasing hormone (PRH) or prolactin-inhibiting hormone (PIH) (also known as dopamine): PRH prompts the anterior pituitary to stimulate breast milk production through the production of prolactin
• PIH inhibits prolactin, and thereby, milk production
• The hypothalamus controls many processes in the body, including mood, hunger and thirst, sleep patterns and sexual function.
• The hypothalamus is connected to and communicates with the anterior lobe through a network of blood vessels.
• It communicates with the posterior lobe by tissue called the pituitary stalk.
• Makes some hormones that are stored elsewhere (in your posterior pituitary).
• Sends signals (hormones) to the pituitary gland, which either releases hormones that directly affect a part of your body or sends another signal (hormone) to a different gland in your body that then releases its hormone.

Disease Conditions and Disorders Affecting the Hypothalamus Gland

• Hypothalamic disease, a physical injury to the head that impacts the hypothalamus is one of the most common causes of hypothalamic dysfunction
• Damaged hypothalamus is also called Hypothalamic dysfunction
• Causes of hypothalamic dysfunction include head injuries, such as a traumatic brain injury
• Causes of hypothalamic dysfunction include Brain infection
• Causes of hypothalamic dysfunction include brain tumour in or around your hypothalamus or brain aneurysms
• Causes of hypothalamic dysfunction include significant weight loss caused by eating disorders, such as bulimia or anorexia
• Causes of hypothalamic dysfunction include brain surgery
• Causes of hypothalamic dysfunction include radiation therapy and chemotherapy
• Causes of hypothalamic dysfunction include birth defects involving the brain or hypothalamus
• Causes of hypothalamic dysfunction include inflammatory disease including multiple sclerosis and neurosarcoidosis
• Causes of hypothalamic dysfunction include some genetic disorders, such as growth hormone deficiency
• Hypothalamus dysfunction plays a role in Hypothalamic-pituitary disorders
• Hypothalamus dysfunction plays a role in hypopituitarism
• Hypothalamus dysfunction plays a role in diabetes insipidus
• Hypothalamus dysfunction plays a role in Prader-Willi syndrome
• Hypothalamus dysfunction plays a role in Kallmann syndrome
• Hypothalamus dysfunction plays a role in Acromegaly and pituitary gigantism
• Hypothalamus dysfunction plays a role in Syndrome of inappropriate antidiuretic hormone
• Hypothalamus dysfunction plays a role in Central hypothyroidism
• Hypothalamus dysfunction plays a role in Functional hypothalamic amenorrhea
• Hypothalamus dysfunction plays a role in Hyperprolactinemia

Signs and Symptoms of Hypothalamus Dysfunction

• High blood pressure or low blood pressure
• Water retention or dehydration
• Weight loss or weight gain with or without changes in appetite
• Infertility
• Poor bone health
• Delayed puberty
• Muscle loss and weakness