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.
What is leptin? Leptin is a hormone released from fat cells in adipose tissue. Leptin signals to the brain, in particular to an area called the hypothalamus. Leptin does not affect food intake from meal to meal but, instead, acts to alter food intake and control energy expenditure over the long term.