This condition can eventually lead to liver scarring, also known as liver cirrhosis and even liver failure. To figure out how alcohol drives ASH, the scientists tested different amounts of ethanol on liver cells called hepatocytes and in mice. They also found that Kupffer cells, special immune cells in the liver, act as a kind of switch that can either ramp up or dial down inflammation, depending on their interactions with liver cells. This glutamate activates mGluR5 receptors on Kupffer cells, which leads to more ROS production and a chain reaction that damages liver cells and sparks inflammation. The scientists also discovered that damaged liver cells and Kupffer cells can form a direct contact point, similar to a synapse in the brain, which they call a “pseudosynapse.” This is a first-of-its-kind finding in liver biology, says the study.