The Impact of a Global Pandemic on Brain, Behavior and Mental Health

Post by Lani Cupo 

What did we learn?

Along with the heavy toll the COVID-19 pandemic has taken on physical health around the globe, there is a rising mental health cost as well, the effects of which are still being discovered. One contributing factor is the experience of increased psychiatric symptoms (e.g. impaired attention, anxiety, insomnia, and depression) among survivors of COVID-19, with some evidence for more severe COVID-19 symptoms being associated with more severe psychiatric symptoms. We also gained a deeper understanding of how the virus affects brain function at the biological level. COVID damages neurovasculature resulting in damage to the blood-brain barrier. The mechanism of action by which COVID impacts the neurovasculature is still unknown, however, it may be through a protein enzyme produced by the virus. However, even those uninfected by the COVID virus are experiencing higher rates of psychological distress during the pandemic, with one study in Israel finding young, unemployed women were at the highest risk for experiencing worsened mental health. Even in the workplace, research indicates that remote work has an impact on team collaboration, leading to more asynchronous communication, such as messages and emails as opposed to synchronous meetings, with employees becoming more siloed. This isolation could contribute to worsened mental health outcomes for those working from home. Overall, the pandemic and measures taken to control the virus can contribute to worsened mental health among survivors, their loved ones, and the general population, the effects of which are still unfolding. 

What's next?

As much of the world scrambles to respond to new variants and organize the distribution of COVID tests and vaccines, attention must be paid to not only the direct consequences of the virus but the indirect impact on mental health as well. Even as there are advancements in treating and preventing COVID-19, the long-term psychiatric consequences that are starting to emerge cannot be disregarded. Mental health is not separate from overall public health, but rather intricately connected. Future research will only continue to uncover insights on how COVID-19 is impacting our brain health as the pandemic unravels.

Using Machine Learning to Advance Our Understanding of the Brain

Post by Leigh Christopher

What did we learn?

2021 saw a big step forward in the use of Machine Learning in neuroscience. It’s no secret that the brain’s complexity is vast, and although scientists have come closer to understanding how it functions, there is still a long way to go. To truly understand some of the mechanisms of the brain, for example how a disease progresses or how we make complex decisions, machine learning can be a valuable tool. Research this year showed that neural networks - otherwise known as ‘deep learning’ - could be used to decode meaningful information from raw neural recordings - such as an animals’ spatial location, speed, or direction, highlighting how powerful machine learning can be in connecting complex neural activity to specific behaviors. Another study used neural networks to better understand how different brain areas process visual information. They were able to predict exactly how the brain would respond to particular stimuli and confirm their hypothesis that the brain responds to specific categories of visual information. Other research this year focused on how to apply machine learning to advance personalized medicine. One study in particular applied machine learning techniques to predict individual drug responses and outcomes in temporal lobe epilepsy, taking into account individual disease characteristics. Rather than classify patients into specific groups, they were able to use the variability in their data to provide more nuanced insights into how patients might respond to various treatments - an important step towards personalized medicine that could apply to a wide range of diseases.

What's next?

2021 was an important year for progressing our understanding of the brain, and further incorporating machine learning techniques into research methodologies. Although there was a big step forward, we are only at the tip of the iceberg in terms of the potential for machine learning to change the way we conduct neuroscience research, and develop real-world applications to advance science and medicine. As we saw this year, machine learning can be used to link complex brain activity to a specific behavior, to help us understand how the brain operates at a system-wide level, to better characterize diseases, and advance personalized medicine. The applications of machine learning are broad, however, there is a need to better translate the insights from these powerful techniques into impact. 2022 will hopefully be a year in improving the interpretability of machine learning for widespread use amongst the scientific community.

How the Immune System Interacts with Our Brains

Post by Anastasia Sares

What did we learn?

Neuroscientists are learning more and more about the role of the body’s immune system, the gut microbiome, and physical illnesses on brain function. Immune systems, when they are working well, defend the body and brain against infection. The brain has its own immune system, which normally stays separated from the rest of the body, protected by a layer of defense called the blood-brain barrier. While much of neuroscience focuses on neurons and the web-like connections between them, support cells (astrocytes) and immune cells (glia) can drastically affect the function of neurons. And if the blood-brain barrier is compromised, both diseases and the body’s immune cells can cross over and create complications.

In many dementias, astrocytes and glia can go rogue and attack neural synapses. In Alzheimer’s disease for example, abnormal proteins may use the cholesterol transport mechanisms in astrocytes to spread to different parts of the brain. Immune cells that are normally outside of the brain can also make their way into the brain when the body is under stress. In Lewy-Body Dementia, immune cells that are normally only found in the body appear around the sites of damaged brain tissue, and their immune response is amped-up. In addition, immune responses inside and outside of the brain can lead to neural inflammation, which may be one of the mechanisms of depression.

Still more surprising connections can be found between digestive health, including the gut microbiome, and neural health. A study by Wu and colleagues found that mice bred without microbiomes in their gut display reduced social behavior towards other mice, and bigger stress response to the few social encounters they did have. In fact, it has recently been suggested that during pregnancy, maternal infections and their corresponding immune responses may lead to both Autism Spectrum Disorder and digestion problems in the fetus, which could be why Autism and digestion issues are often linked. This is part of a research trend looking at the gut-brain connection, which made its way into pop science starting in 2015 with books like Gut, The Brain-Gut Connection, and the Psychobiotic Revolution.

Then there are, of course, the neurological side effects of the Sars-Cov-2 virus, which emerged in 2019 and has been the focus of fever-pace research since then. For example, a post-mortem study compared brains of people who died from COVID-19 to brains of people who died from other causes, and found that COVID patients had increased brain inflammation and damage to axons in the brain (the tendrils that neurons use to communicate with one another). The fact that COVID can cross the blood-brain barrier and have long-lasting effects on the nervous system make vaccination access and uptake even more important.

What's next?

Though a good proportion of studies examining the connection between the nervous system and the immune system are still taking place in mice and rats, there seems to be a transition toward more human studies, solidifying the connection between these two systems. Looking at the human body as a whole is bound to bring new insights into how our immune systems interact with and impact brain function.