Pineal Gland - An Overview

Introduction:

The pineal gland is situated in the middle of the brain. It secretes melatonin and regulates the body's circadian rhythm. It also secretes other hormones. It helps regulate female hormones, heart health, and mood stability.

What Is Pineal Gland?

The pineal gland is a small endocrine gland located in the brain's center. It is a major gland that releases melatonin. Other names for this gland are pineal body, epiphysis cerebri, and epiphysis. The pineal gland is situated in the epithalamus, deep in the brain, in the groove above the thalamus. This area coordinates many functions related to the senses. Its shape is similar to that of a tiny pinecone.

The pineal gland secretes melatonin and many other hormones. Melatonin is the major hormone secreted by the pineal gland, and it helps maintain the sleep-wake cycle. The underlying condition or an injury to the pineal gland may disrupt the pineal gland, resulting in hormonal imbalance. Hormones are chemical substances that have a role in maintaining many bodily functions. Hormone imbalance may lead to sleep disturbances and cardiac problems, affecting mood stability.

The pineal gland comprises neurons, neuroglial cells, and specialized secreting cells called pinealocytes. These cells form melatonin and release it into cerebrospinal fluid, which flows through the brain and spinal cord and then into the bloodstream.

What Is the Role of Melatonin in the Pineal Gland?

Melatonin is a hormone produced by the pineal gland. This hormone helps synchronize the circadian rhythm in different parts of the body. The pineal gland is considered to be light-sensitive. The pineal gland tends to release melatonin in the dark. This hormone helps with falling asleep. The release of melatonin in the body makes the body feel tired, and the individual may fall asleep.

Melatonin is called the sleep hormone. The individual may not need melatonin to fall asleep, but high melatonin levels can help provide better sleep. Some conditions can affect the release of melatonin.

These include:

• Pineal tumors.

• Injuries may affect the functioning of the pineal gland.

• Craniopharyngiomas.

• Genetic disorders that are considered rare.

• Calcifications in the pineal gland.

Sleep may be affected by many other conditions and environmental factors. Research has found that it becomes difficult for humans to adapt to changing seasons without the pineal gland and its secretion of melatonin.

The pineal gland may suffer because of pineal cysts. These are benign and not harmful. Sometimes, precocious puberty may be seen among those with pineal cysts or tumors. This aspect is unclear because it may be due to melatonin or human chorionic gonadotrophin. Gonadotrophin is secreted from the pineal tumors.

Melatonin Supplements:

Many individuals facing sleep disturbances must seek help from doctors. The reason is underlying conditions. Sleep disturbances can be managed with melatonin supplements. These supplements give the body small amounts of melatonin and help with falling asleep.

The benefits of melatonin supplements include:

• Jet lag or switching to time zones.

• Delayed sleep-wake phase disorder (DSWPD).

• Helps those children affected by autism and neurodiverse problems.

• Helps those feeling anxiety before or after surgery.

A study done in 2022 observed a definite rise in the use of melatonin supplements from 1999 to 2018.

Melatonin supplements must be taken only after consulting a doctor. It should be avoided among:

• Those on medications for chronic conditions.

• Individuals over the age of 65.

• Women, breastfeeding children.

• Those who are pregnant.

• Those allergic to melatonin supplements.

A study has found that melatonin supplements may also contain serotonin.

Side effects of melatonin include:

• Individuals may feel drowsy.

• Feel grogginess in the morning.

• One may get vivid and intense dreams.

• Rise in blood pressure.

• Decreased body temperature.

• Feel anxiety.

• Confusion may be felt.

Certain medications may cause interactions with melatonin.

These include:

• Fluvoxamine.

• Nifedipine.

• Birth control pills.

• Blood thinners or Anticoagulants.

• Medications for diabetes.

• Immunosuppressants.

What Is the Role of Melatonin on Heart Health?

Melatonin plays an important role in protecting the heart. A 2016 study found that melatonin can help fight conditions such as atherosclerosis and hypertension. Researchers have observed that melatonin receptors are present throughout the body, including in the heart.

This helps in processes such as:

• Regulation of blood pressure.

• Regulation of heart rate.

• Vascular resistance.

A study done in 2018 observed that maintaining melatonin levels helps manage many bodily functions. It was also observed that melatonin helps delay and prevent age-related heart conditions.

What Is the Role of Melatonin on Female Hormones?

The menstrual cycle may affect the pineal gland and its secretion of melatonin.

A 2020 study found that increased melatonin levels during the late luteal phase may influence sex hormones. Researchers also noted that melatonin levels are lower during the transition from premenopause to postmenopause.

Recent studies have noticed that progesterone can influence the rise of melatonin. This indicates that melatonin responds to the menstrual cycle. It was also noticed that melatonin can affect sexual health and reproduction.

What Is the Role of Melatonin in Mood Stabilization?

Mood disorders are based on the size of the pineal gland. A study done in 2015 noticed that a lower volume of the pineal gland may be the reason for the development of schizophrenia and other mood disorders. A study done in 2019 found that individuals with major depressive disorder (MDD) were found to have pineal gland cysts. Researchers found that the pineal gland may play a role in depression.

What Is the Role of Melatonin on Cancer?

Melatonin is found to exhibit antitumor activity. Researchers have noticed that melatonin can work at cellular levels and help reduce cancer progression. They noted that hormonal cancer tends to occur among those who do night shifts. The reason for this is the disruption of melatonin levels at night.

What Are the Symptoms of Pineal Gland Problems?

Pineal gland tumors may show the following symptoms.

These include:

• Experiences seizures.

• Face problems related to memory.

• Experience headaches.

• Nausea and vomiting may occur.

• Visual disturbances.

How to Diagnose the Health of the Pineal Gland?

The health of the pineal gland can be determined by doing imaging tests.

These include:

• Magnetic Resonance Imaging (MRI): An imaging test to know the details of internal structures like organs, bones, muscles, and blood vessels.

• Computed Tomography (CT): This imaging test is used to determine the details of internal structures. This technique provides better clarity than X-rays.

• X-rays: X-rays are used to learn about the calcifications of the pineal gland.

Conclusion:

The pineal gland is a small but powerful endocrine gland that secretes melatonin and plays a major role in the circadian rhythm. Apart from the sleep-wake cycle, it influences heart health, mood stability, cancer, and menstrual cycle. Disruption in melatonin levels may affect various processes in the body. Hence, it becomes important to know about the pineal gland, its hormones, its influences, and its symptoms. Knowing about the gland helps in identifying the conditions related to the gland early. Early diagnosis always leads to effective treatment. This, in turn, helps achieve a good quality of life.