Mirror neurons: a definition. Description: Professor Christian Keysers explains that mirror neurons in the premotor cortex respond when we perform an action and also when we see someone else perform that action. This is similar to empathy. Transcript: Mirror neurons are a set of neurons that we discovered in the premotor cortex of the monkey.
lectin. [ 1 lekâ²tin] 2  a protein in seeds and other parts of certain plants that binds with glycoproteins and glycolipids on the surface of animal cells, causing agglutination. Some lectins agglutinate erythrocytes in specific blood groups, and others stimulate the production of T lymphocytes.
Lecithin is also known as phosphatidylcholine. It is a fat, or lipid, material found in the membranes of all living cells and functions to regulate the entry and exit of cellular nutrients. While lecithin is found in many foods, either naturally or as a food additive, it is also sold as a dietary supplement.