Li-Huei Tsai facts for kids

Li-Huei Tsai (Chinese: 蔡立慧; born March 18, 1960) is an American neuroscientist. She studies how our brains learn and remember things. She is the director of the Picower Institute for Learning and Memory at the Massachusetts Institute of Technology (MIT).

Dr. Tsai is famous for her work on brain problems that affect learning and memory. She especially researches Alzheimer's disease. This disease makes people lose their memory and thinking skills. She also looks at how certain proteins, like CDK5, and changes in our DNA affect the disease. Her lab has also found new ways to study brain diseases using special cells called induced pluripotent stem cells.

Education and Early Career

Li-Huei Tsai was born and grew up in Taiwan. In 1984, she received a special scholarship to study veterinary medicine at the University of Wisconsin–Madison. While there, she became very interested in studying cancer.

She earned her PhD in 1990 from the University of Texas Southwestern Medical Center. In 1991, Dr. Tsai joined a research lab at the Cold Spring Harbor Laboratory. Later, she worked at the Massachusetts General Hospital Cancer Center. In 1994, she became a professor at Harvard Medical School. She moved to MIT in 2006. In 2009, she became the director of the Picower Institute for Learning and Memory. She also helped start MIT's Aging Brain Initiative. In 2019, she became a co-director of the Alana Down Syndrome Center at MIT.

Discoveries About the Brain

When Dr. Tsai first started her research, she studied proteins called cyclin-dependent kinases (CDKs). These proteins help control how cells divide and grow. She found a specific CDK called CDK5. It was special because it was mostly active in the brain, not in other body parts. She also learned that CDK5 needs another protein called p35 to work.

After moving to Harvard, she focused on CDK5 and p35. She found that if mice didn't have p35, their brains didn't develop correctly. They also had seizures. She discovered that CDK5-p35 activity is important for brain cells (neurons) to grow their connections.

CDK5 and Alzheimer's

Dr. Tsai also found something important about CDK5 and Alzheimer's disease. While CDK5 is needed for a healthy brain, having too much of it can be bad. She saw that a shorter version of p35, called p25, built up in damaged brain tissue. This happened in mice with brain damage and in brain samples from people who had Alzheimer's.

In one experiment, Dr. Tsai made mice that had more CDK5 activity. These mice started showing signs of Alzheimer's. They had trouble learning and remembering. They also lost brain cells and developed sticky clumps in their brains called amyloid plaques. These plaques are a key sign of Alzheimer's.

Finding Ways to Help

After moving to MIT, Dr. Tsai started looking for ways to help or even reverse Alzheimer's symptoms.

In a 2007 study, she trained mice to find a hidden platform in a pool. When she gave the mice Alzheimer's-like symptoms, they couldn't find the platform anymore. But then, she put some of these mice in a "rich environment." This was a place with lots of toys, tunnels, and other mice to play with. After some time, these mice could find the platform again! This showed their memories had improved.

Dr. Tsai then found a way to get the same results as the "rich environment" using a medicine. This medicine stopped certain enzymes called histone deacetylases (HDACs). These enzymes can block genes that are important for brain health. Later, she showed that one specific HDAC, called HDAC2, could block genes needed for learning and memory. By stopping HDAC2, some memory function could be brought back.

New Discoveries

Dr. Tsai has also found out more about how Alzheimer's affects the brain's DNA. She showed that DNA breaks, which are needed for learning, can also lead to memory problems as we get older. This is because our bodies become less good at fixing DNA as we age. She also found that the genes linked to Alzheimer's mostly affect the brain's immune system, not just the brain cells themselves.

In 2016, Dr. Tsai showed something amazing. She used a special light that flashed 40 times a second (40 hertz) on mice. This visual stimulation greatly reduced the beta amyloid plaques in their brains. This might work by creating special brain waves called gamma oscillations.

More recently, Dr. Tsai has created a lab model of the Blood–brain barrier. This is a protective shield around our brain. She uses this model to study how certain genes, like APOE, can cause this barrier to break down in Alzheimer's disease.

Awards

• 1997 Investigator, Howard Hughes Medical Institute
• 2008 Academician, Academia Sinica
• 2010 Glenn Award for Research in Biological Mechanisms of Aging
• 2011 Member, National Academy of Medicine
• 2011 Fellow, American Association for the Advancement of Science
• 2016 Mika Salpeter Lifetime Achievement Award, Society for Neuroscience
• 2019 Fellow, National Academy of Inventors
• 2019 Hans Wigzell Research Foundation Science Prize

See also

• Alzheimer's disease research
• Neuroscience of ageing