The vast size of the human brain and its ever-growing network is astounding enough to imagine — a large piece of gray matter that continuously builds new connections between the 100 billion neurons it houses; the key to how our brains got to grow so large in just a few million years of evolution. However, in a powerhouse of this size — controlling our day-to-day decisions, motor functions, vision, and nerves — so much depends upon a small gateway, known as the “third eye” for its location between the eyes, nestled just below the center of your forehead. It’s only about the size of a pea, controlled by the hypothalamus (which itself is only about one three-hundredth the weight of the brain) and is heavily guarded by a bony structure within the skull, the sella turcica.
Perhaps most striking about this so-called third eye is that humans are one of the few species in which the three lobes are less distinct, with the intermediate lobe being only a few thin cell layers apart from the anterior and posterior lobes. Think of the structure as a traffic light blinking signals from three different directions. The pituitary gland’s functioning is closely connected with the hypothalamus region of the brain, which supplies it with oxygenated blood, along with the anterior lobe and the sex organs.
Due to the pituitary’s constant interaction with messages from glands throughout the brain — relayed from all three of its lobes — it is known as the master gland. Those who have heard of it usually know of the pituitary in the way that it affects growth (the result of hormones secreted from the anterior lobe) — the overactive kind, meaning sudden, raging and out of control growth spurts — but the master gland’s job isn’t all that simple. It also regulates body temperature, blood pressure, water and salt concentrations throughout the body — as well as the kidneys, thyroid, and some functions of the sex organs. Even our sleep patterns are the result of the pituitary gland, as it works with the pineal gland to produce the sleep-promoting hormone melatonin, setting our bodies into ritual circadian rhythms every night. Therefore, its regular functioning as a glandular switchboard is the key to our well-being.
For many years, its functions were not fully understood. Claudius Galen, an ancient Roman physician (a team doctor for the gladiators, as it were), thought that it was merely the source of nasal mucus, and accordingly its name comes from the Latin phrase: “Gland from which the slime drips.” It took nearly 2,000 years for physicians to refute this claim. Galen did, however, correctly identify the central nervous system, to which the pituitary is connected.
In India, the gland was held in higher regard, having been called “the seat of the mind,” a critical energy point for practitioners of chakra for attaining the state of pure consciousness — a condition in which one experiences the revelation of absolute truth. To this day, modern practitioners of chakra hold that the frontal lobe regulates emotional intelligence — the driving force that sees the poetic part of life, perceiving the world through metaphor and music — while the anterior lobe focuses on concrete problems and intellectual thoughts.
Things became a bit more complicated, however, in the 19th century, when epidemics of tuberculosis wiped out nearly one quarter of Europe’s adult population. By 1918, the outbreak accounted for one-sixth of all deaths in France alone. Patients that became comatose due to this disease showed signs of anomalies in the hypothalamus — betraying an important mind and body connection in the pituitary gland. It was hardly the first case demonstrating this either. An examination of nearly 30,000 brains revealed that patients who suffered ulcers also had abnormalities in the same region. What could this small structure within the brain have to do with such a remote part of the body?
In 1971, Andrew Schally recognized the gonadotropin-releasing hormone as a crucial chemical messenger within the hypothalamus. Six years later, Schally discovered that it was secreted into the anterior pituitary via the bloodstream, through which it would then reach the sex organs. He was awarded the Nobel Prize in medicine for his work. Thanks to Schally, a great deal of physical conditions could be understood in greater depth why strokes or sudden weight gain can cause a loss of sexual desire, and why cutting off blood circulation can cause damage to the reproductive organs and digestive system — paving the way for new possible treatments.
We now know that the anterior lobe is associated with hormones released in response to physical stress, and that in many ways the lobe is responsible for how the body deals with reacting to anxieties, while the frontal pituitary is in charge of the production of oxytocin, the chemical inducing feelings of intimacy as well as strengthening social bonds — interestingly, this friendship-fortifying ability of the chemical works on humans and animals alike, as studies conducted on people who petted their dogs for five minutes effectively found higher than normal levels of oxytocin in both the owners and their dogs compared to subjects who had not engaged in this exchange. Oxytocin was later synthesized in laboratories for the purpose of starting and increasing the speed of labor during childbirth, as well as to stop the rate of bleeding that follows delivery.
However, this is only scratching the surface of what the chemical has to offer. If it can help with physical complications when synthesized, it also might play an important role when it comes to psychological and personality disorders. Two important studies have found that it reduces the symptoms of autism. Little is understood at the moment regarding autism, a behavioral disorder in which patients limit their degree of interaction with other people, confining themselves to little beyond a narrow set of interests. It is a neurodevelopmental disorder, with an onset in early childhood, leading many people to incorrectly attribute its symptoms to vaccinations.
In 2007, a study sponsored by the National Institutes of Health and the Children’s Brain Research Foundation found a connection between the symptoms of autism in children and a lack of function in the genes that produce oxytocin — and further research showed that oxytocin is also directly related to regulating levels of fear and trust, the latter of which tends to be built up more with high concentrations of oxytocin, while minimizing fear and uncertainty. It has also shown to help with the recognition of emotions, which autism patients typically have difficulty with. Even empathy has been shown to increase due to changes in levels of oxytocin, the lack of which has been attributed to a number of social problems of the day, such as school bullying.
Since the beginning of time, people have sought to understand emotions — a thirst that has echoed throughout the humanities for centuries, but has long been a perplexing struggle for the sciences. While there’s an evident disconnect between the practice of medicine and the discipline of psychology, it seems that perhaps the golden age of neuroscience in which we live is gradually bridging that gap — finding a way to uncover the ingredients behind sadness and feelings of joy, and with this correcting some of the long-term trends molded by centuries of evolution, changing life and the experience of being alive for the better.
This article was originally published in the Fall 2015 issue of Brain World Magazine.