Downregulation

Downregulation is a decrease in a receptor in response to an increase in a ligand (e.g. hormone, neurotransmitter, etc.). For example, drug abuse may result in the downregulation of dopamine receptors, which in turn would require more drug to achieve the same effect. Drinking coffee may result in the upregulation in adenosine receptors. As a result, coffee drinkers may experience headaches or increased sleepiness when in withdrawal. Downregulation and upregulation are examples of homeostatically driven negative feedback that provides high accuracy and stability of a control system in a changing context.

This glossary entry is used to explain texts in SuperMemo Guru series on memory, learning, creativity, and problem solving