Mouse Study Finds a Sea Squirt Compound That Reverses Signs of Brain Aging

Researchers from Xi'an Jiaotong-Liverpool University, Stanford University, Shanghai Jiao Tong University and the University of Chinese Academy of Sciences have found that a compound in sea squirts, marine animals eaten in parts of Korea and Japan, reversed several signs of aging in old mice. The study focused on plasmalogens, a type of fat molecule that forms an important part of cell membranes and is especially abundant in the brain, heart and immune cells.

Plasmalogen levels naturally decline as people age. Lower levels have also been observed in neurodegenerative diseases including Alzheimer's and Parkinson's. To test whether restoring plasmalogens could help, the researchers added the compound to the diets of aged mice and tracked changes in their behavior and bodies. Professor Lei Fu, the study's corresponding author, said the treated mice "grow new black hair that is thicker and glossier than aged mice not fed the supplement," alongside improvements in cognitive tests.

To measure learning and memory, the team used the Morris water maze, a standard test in which mice learn the location of a hidden platform in a pool. After five days of training, aged mice given plasmalogens reached the platform significantly faster than aged mice that had not received the supplement, performing more like younger animals. Examining the mice's brains, the researchers found that plasmalogen-treated mice had more synapses, the junctions where nerve cells communicate. Inflammation in their brains was also substantially lower than in untreated aged mice.

Professor Fu said the compound appears to increase molecules that support the growth of neurons and synapses, suggesting plasmalogens may promote neuroregeneration, the repair and regrowth of nerve cells and their connections. The researchers say plasmalogens may also affect the structure of synaptic membranes directly, making them more flexible. The findings, described as the first detailed look at how plasmalogens influence the aging brain, come from experiments in mice and have not yet been tested in humans.