Study reveals how general anesthetics affect the brain

New research reveals for the first time that diverse drugs that induce general anesthesia activate a brain circuit that brings on sleep. The scientists at Duke University in Durham, NC who carried out the study, suggest that the findings will help to develop better drugs that can induce sleep with fewer adverse reactions. Since 1846, when a dentist and a surgeoncarried out the first successful surgical procedure to use anesthesia, a number of general anesthetic drugs have emerged. Yet, until the recent study, it had not been clear how these substances produced a loss of consciousness. In a Neuron paper, the researchers describe how they discovered the cells in the hypothalamus at the base of the brain. The cells, which consist mainly of neuroendocrine cells, sit "in and near the supraoptic nucleus" in the hypothalamus and "are persistently and commonly activated by multiple classes of [general anesthetic] drugs," they write. Neuroendocrine cells are cells that, as with neurons, or nerve cells, receive signals from the nervous system except that they respond by producing and releasing hormones.