Sept. 23, 2021 | With nearly 100 billion neurons and 100 trillion connections, the human brain remains one of the greatest mysteries in science and one of the greatest challenges in medicine. Neurological and psychiatric disorders exact a tremendous toll on individuals, families, and society. Despite the many advances in neuroscience in recent years, the underlying causes of most neurological and psychiatric conditions remain largely unknown, due to the vast complexity of the human brain. The National Institutes of Health in 2014 launched the Brain Research through Advancing Innovative Neurotechnologies, or BRAIN, Initiative in 2014 in an effort to develop new tools and technologies to understand neural circuit function and capture a dynamic view of the brain in action. Some of the projects in this initiative include proposals to develop ultrasound methods for measuring brain activity and the use of deep brain stimulation to treat traumatic brain injuries.

Sept. 23, 2021 | The largest organ in the human body is the skin that covers it, but the brain is easily the most complex organ. The jelly-like mass weighs roughly three pounds but it contains one hundred billion nerve cells, or neurons, many of which were used to process the words you just heard. Each neuron can make contact with thousands or even tens of thousands of other neurons through tiny structures called synapses. The “grey matter” you hear about so often is the cell bodies of the neurons. The brain also contains billions of glial cells that support neuron function by fixing neurons in place, supplying nutrients, and removing dead neurons. New brain cells are born throughout our lives, a process called neurogenesis. The brain will experience periods of growth followed by periods of consolidation when excess connections are pruned, with the most notable spurts of growth during the first two years of life, then in puberty and then a final burst during young adulthood.

Sept. 23, 2021 | Our brain is actually something of a committee of three, each experts in their respective fields. The three units are the forebrain, the midbrain and the hindbrain. The hindbrain includes the upper part of the spinal cord, the brain stem, and a wrinkled ball of tissue called the cerebellum. The hindbrain controls the body’s vital functions such as respiration and heart rate, and the cerebellum coordinates movement and is involved in learned rote movements. The midbrain is the uppermost part of the brainstem, which controls some reflex actions and is part of the circuit involved in the control of eye movements and other voluntary movements. The forebrain is the largest and most highly developed part of the human brain. It consists primarily of the cerebrum and the structures hidden beneath it. The cerebrum sits at the top of the brain and is the source of intellectual activities. It holds your memories, allows you to plan and enables you to imagine and think.

Sept. 23, 2021 | Split into two halves, or hemispheres, by a deep fissure, the cerebrum is the largest part of the human brain. Despite the split, the two hemispheres communicate with each other through a thick tract of nerve fibers that lies at the base of this fissure. Although the two hemispheres seem to be mirror images of each other, they are different. For instance, the ability to form words seems to lie primarily in the left hemisphere, while the right hemisphere seems to control many abstract reasoning skills. Nearly all of the signals from the brain to the body and vice-versa cross over on their way to and from the brain. This means that the right cerebral hemisphere primarily controls the left side of the body while the left hemisphere primarily controls the right side. When one side of the brain is damaged, the opposite side of the body is affected. For example, a stroke in the right hemisphere of the brain can leave a person’s left arm and or left leg paralyzed.

Sept. 23, 2021 | Each hemisphere of the brain’s cerebrum is divided into four sections, or lobes. These lobes specialize in different functions. The frontal lobes, which lie directly behind the forehead, control thinking, planning, organizing, problem solving, short-term memory and movement. The frontal lobes seem to do these things is by acting as short-term storage sites, allowing one idea to be kept in mind while other ideas are considered. The parietal lobes, located behind the frontal lobes, interpret sensory information, such as taste, temperature and touch. At the back of the brain are the occipital lobes, which process images from your eyes and link that information with images stored in memory. Last but not least are the temporal lobes, which lie under the parietal and frontal lobes. The temporal lobes process information from your senses of smell, taste and sound. They also play a crucial role in forming and retrieving memories.