New Insights into the Brain’s Motor Cortex

National Institutes of Health

The brain’s primary motor cortex is a thin band of nerve cells and circuits that extends from the top of the head and downward on both sides. It’s long been thought to have a straightforward role as the brain’s command center for voluntary muscle movements, sending out signals that trigger movements in specific body parts. Complex movements were believed to be coordinated by other areas of the brain.

A century ago, a systematic study involved electrically stimulating different human brain areas during surgery to see the resulting body movements. The study revealed a well-organized “body map.” This research led to a familiar drawing of the cortical band that’s taught in biology classrooms to this day. The drawing shows the motor cortex as an orderly continuum from head to toe. One end primarily controls face-related movements, followed by regions that control the hands and then the feet.

In recent decades, studies have questioned this linear body map in the motor cortex. For instance, studies in nonhuman primates suggested that the map may be divided into concentric zones instead of a continuous row. So digits like fingers might be in the middle, surrounded by areas for the wrists, elbows, then shoulders. Other studies found that large portions of the primary motor cortex seemed to prompt no muscle movements at all, but revealed connections to brain areas controlling other functions.

To learn more, a team led by Drs. Evan Gordon and Nico Dosenbach at Washington University in St. Louis used an advanced imaging method called precision fMRI to reexamine the function and organization of the human motor cortex. The technique involved repeatedly scanning each person’s brain over many hours to create high-resolution brain maps for each individual. Results appeared in Nature on April 19, 2023…

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How Vagus Nerve Stimulation Can Help Some Patients Improve Their Recovery After Stroke

By Michael Clayton, Mayo Clinic

A vagus nerve stimulation device, approved by the Food and Drug Administration, is being used in rehabilitation to help patients recovering from an ischemic stroke. If a patient is having trouble using their hand or arm after a stroke, this stimulation device helps create new pathways in the brain as the person performs exercises. This can help the person regain function faster than rehabilitation alone.

Dr. Jonathon Parker, a Mayo Clinic neurosurgeon, discusses how the vagus nerve stimulation device is helping some stroke patients recover their mobility in this Mayo Clinic Minute.

An ischemic stroke can be life-changing for those who survive. Many people may need speech, physical or occupational therapy to regain their abilities. The vagus nerve stimulator device also used to treat epilepsy, can help some patients recover strength in their arms, even many months or years after their stroke.

"We can stimulate the nervous system in a way that we can then augment the body's ability to recover from something like a stroke," says Dr. Parker.

This advanced device can be used to deliver stimulation at the moment the patient is performing a rehabilitation exercise. Pairing this action can help patients recover lost strength from stroke and, in many cases, regain function in their hands and arms.

"We study this therapy in patients who are already in that chronic phase of recovery from their stroke. Nearly half of those patients were able to have a very significant improvement in their motor strength," he says.

Researchers also are studying vagus nerve stimulation as a potential treatment for a variety of other conditions. Research is looking at the potential benefits of the therapy for rheumatoid arthritis, inflammatory bowel disease, bipolar disorder, obesity, and Alzheimer's disease.

It’s Mental Health Awareness Month

National Center for Complementary and Integrative Health

May is Mental Health Awareness Month, a good time to think about ways in which you can protect your mental health, including taking steps to manage stress.

Long-term stress can contribute to or worsen many mental and physical health problems. But fortunately, there are ways to counteract its effects. We have access to a built-in “stress reset button” that acts as an antidote to stress. It’s called the relaxation response. It’s the opposite of your body’s response to stress. The relaxation response slows your heart rate, lowers your blood pressure, and decreases oxygen consumption and levels of stress hormones.

By learning simple techniques that produce the relaxation response—such as progressive muscle relaxation, simple mindfulness exercises, and slow, deep breathing—you can help prevent stress from building up. That’s good for both your mind and your body.

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Surgeon General Outlines Framework to Address Loneliness

The Hill | By Lauren Sforza

Surgeon General Vivek Murthy, M.D., plans to introduce a three-part framework to address loneliness in the US, as about half of Americans are experiencing loneliness at any given time, and social disconnection can lead to an increased risk of mental health and physical issues in addition to premature death. Social connection must be a priority and "will require reorienting ourselves, our communities, and our institutions to prioritize human connection and healthy relationships," Dr. Murthy writes.

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