Your brain is keenly aware of what’s going on inside your body at all times. Some things are obvious – like when you feel hungry or thirsty. But some things you never notice – like how blood vessels all over your body simultaneously contract as you stand up, so you don’t lose blood flow to your brain. But how does your brain know when to send the signal to squeeze? It’s all part of concept scientists call interoception – the dialogue between your brain and the rest of your body.
Interoception is involved in everything from keeping us balanced while we walk, to keeping our blood pressure and heart rate steady. It even appears to influence our moods and emotions. And thanks to recent discoveries, we’re learning more about how interoception works. Researchers identified two special channels in neurons that react to touch and named them PIEZO1 and PIEZO2. Since first identifying these pressure sensors, researchers have found PIEZOs in internal organs like the heart, lungs, and blood vessels lining the stomach… suggesting many physiological functions involve mechanical forces that our brain and other parts of our nervous system must monitor and influence. As the study of interoception grows, scientists are hopeful the field could lead to breakthroughs in treating heart disease, controlling blood pressure, relieving anxiety and depression, and treating a number of other disorders. Learn more about Scripps Research at scripps.edu.
Covid-19 is complex. It can affect the nervous system, leading to language disorders, strokes and seizures. Scientists are still trying to understand why. 75% of people hospitalised with the virus continue to suffer from secondary symptoms at least six months after they recover. Many find it hard to function in their daily lives. Researchers hope understanding Covid’s impact on the brain could pave a way for treatment.
Indoor dining, workout classes, concerts. These once commonplace events are coming back into daily life. But because of Covid-19, everyone now has a different level of comfort. What happens in the brain as we decide what’s risky or not? Photo illustration: Laura Kammermann
The first event in our Lab Notes online series features two researchers from our South Coast Network Centre talking about early brain changes in Alzheimer’s. Dr Karen Marshall shares her work studying how waste disposal and recycling systems in nerve cells cause damage in Alzheimer’s disease, and whether there could be ways to rescue cells from this. Dr Mariana Vargas-Caballero speaks about her research into brain cell connections and how they are affected in Alzheimer’s. The event is chaired by Dr Katy Stubbs from Alzheimer’s Research UK, and also features a Q&A session.
Neuroscience Professor Seth Tomchik, PhD, focuses on two major research areas, the neuroscience of learning and memory, and diseases that affect learning and memory, including neurofibromatosis type one. Neuroscience is now the largest department on the Florida campus of Scripps Research.
The department’s faculty and staff, together with graduate students enrolled in the institute’s Skaggs Graduate School, push the boundaries of scientific knowledge to benefit humanity. Watch all 11 videos in this series to see their work in more detail. Scripps Research is an independent, nonprofit biomedical research institute ranked the most influential in the world for its impact on innovation. With campuses in La Jolla, California, and Jupiter, Florida, the institute advances human health through profound discoveries that address pressing medical concerns around the globe. Scripps Research also trains the next generation of leading scientists at the Skaggs Graduate School, consistently named among the top 10 U.S. programs for chemistry and biological sciences. Learn more at http://www.scripps.edu.
In 2020, the study of the SARS-CoV-2 virus was undoubtedly the most urgent priority. But there were also some major breakthroughs in other areas. We’d like to take a moment to recognize them.
1. This year, we learned that we had severely underestimated the human brain’s computing power. Researchers are coming to understand that even the dendritic arms of neurons seem capable of processing information, which means that every neuron might be more like a small computer by itself.
2. The new Information Theory of Individuality completely reimagines the way biologists have traditionally thought about individuality. Armed with information theory, the researchers found objective criteria for defining degrees of individuality in organisms.
3. Deprived of sleep, we and other animals die within weeks. More than a century of scrutiny failed to explain why lack of sleep is so deadly. This year, an answer was finally found — not inside the brain, as expected, but inside the gut.
Stroke is far more common than you might realize, affecting more than 795,000 people in the U.S. every year. It is a leading cause of death and long-term disability. Yet until now, treatment options have been limited, despite the prevalence and severity of stroke.
Not so long ago, doctors didn’t have much more to offer stroke victims than empathy, says Kevin Sheth, MD, Division Chief of Neurocritical Care and Emergency Neurology. “There wasn’t much you could do.” But that is changing. Recent breakthroughs offer new hope to patients and families. Beating the Clock Think of stroke as a plumbing problem in the brain. It occurs when there is a disruption of blood flow, either because of a vessel blockage (ischemic stroke) or rupture (hemorrhagic stroke).
In both cases, the interruption of blood flow starves brain cells of oxygen, causing them to become damaged and die. Delivering medical interventions early after a stroke can mean the difference between a full recovery and significant disability or death. Time matters. Unfortunately, stroke care often bottlenecks in the first stage: diagnosis. Sometimes, it’s a logistical issue; to identify the type, size, and location of a stroke requires MRI imaging, and the machinery itself can be difficult to access.
MRIs use powerful magnets to create detailed images of the body, which means they must be kept in bunker-type rooms, typically located in hospital basements. As a result, there is often a delay in getting MRI scans for stroke patients. Dr. Sheth collaborated with a group of doctors and engineers to develop a portable MRI machine. Though it captures the images doctors need to properly diagnose stroke, it uses a less powerful magnet. It is lightweight and can be easily wheeled to a patient’s bedside.
“It’s a paradigm shift – from taking a sick patient to the MRI to taking an MRI to a sick patient,” says Dr. Sheth. Stopping the Damage Once a stroke has been diagnosed, the work of mitigating the damage can begin. “Brain tissue is very vulnerable during the first hours after stroke,” says vascular neurologist Nils Petersen, MD. He and his team are using advanced neuro-monitoring technology to study how to manage a patient’s blood pressure in the very acute phase after a stroke.
Dr. Petersen’s research shows that optimal stroke treatment depends on personalization of blood pressure parameters. But calculating the ideal blood pressure for the minutes and hours after a patient has a stroke can be complicated. It depends on a variety of factors—it is not a one-size-fits-all scenario. Harnessing the Immune System Launching an inflammatory reaction is how the body responds to injury anywhere in the body – including the brain, following stroke. However, in this case, the resulting inflammation can sometimes cause even more damage.
But what if that immune response could be used to the patient’s advantage? “We’re trying to understand how we can harness the immune system’s knowledge about how to repair tissues after they’ve been injured,” says Lauren Sansing, MD, Academic Chief of the Division of Stroke and Vascular Neurology. Her team is working to understand the biological signals guiding the immune response to stroke.
That knowledge can then direct the development of targeted therapeutics for the treatment of stroke that minimize early injury and enhance recovery. “We want to be able to lead research efforts that change the lives of patients around the world,” says Dr. Sansing.
Learn about these developments and more in the video above.
Many studies suggest that exercise can help protect our memory as we age. This is because exercise has been shown to prevent the loss of total brain volume (which can lead to lower cognitive function), as well as preventing shrinkage in specific brain regions associated with memory. For example, one magnetic resonance imaging (MRI) scan study revealed that in older adults, six months of exercise training increases brain volume.
Another study showed that shrinkage of the hippocampus (a brain region essential for learning and memory) in older people can be reversed by regular walking. This change was accompanied by improved memory function and an increase of the protein brain-derived neutropic factor (BDNF) in the bloodstream.
The brain is highly dependent on blood flow, receiving approximately 15% of the body’s entire supply – despite being only 2-3% of our body’s total mass. This is because our nervous tissues need a constant supply of oxygen to function and survive. When neurons become more active, blood flow in the region where these neurons are located increases to meet demand. As such, maintaining a healthy brain depends on maintaining a healthy network of blood vessels.
Regular exercise increases the growth of new blood vessels in the brain regions where neurogenesis occurs, providing the increased blood supply that supports the development of these new neurons. Exercise also improves the health and function of existing blood vessels, ensuring that brain tissue consistently receives adequate blood supply to meet its needs and preserve its function.
Recently, a growing body of research has centred on microglia, which are the resident immune cells of the brain. Their main function is to constantly check the brain for potential threats from microbes or dying or damaged cells, and to clear any damage they find.
With age, normal immune function declines and chronic, low-level inflammation occurs in body organs, including the brain, where it increases risk of neurodegenerative disease, such as Alzheimer’s disease. As we age, microglia become less efficient at clearing damage, and less able to prevent disease and inflammation. This means neuroinflammation can progress, impairing brain functions – including memory.