Scientists have identified a mechanism that contributes to the lack of motivation and negative emotions of cocaine withdrawal. Their discovery, published in the latest Proceedings of the National Academy of Sciences, offers a deeper look into the cellular and behavioral implications of addiction.Bradley Winters, lead author of the PNAS paper and a freshly minted WSU doctor of neuroscience, says he, his major advisor Yan Dong, and colleagues at WSU, the University of Pittsburgh and the European Neuroscience Institute focused on cells that produce a signaling molecule called cannabinoid receptor 1, or CB1.
Its main function is regulating the communication between nerve cells related to the functions like memory, motor control, perception, mood and appetite. Those same functions are affected by THC, the cannabinoid in its namesake cannabis, or marijuana."These receptors are not here just to make marijuana fun," says Winters. "Their main function is changes in how nerve cells communicate with each other."The researchers studied the CB1 cells by producing a line of mice in which the cells that make CB1 were labeled fluorescently. The researchers could then identify the cells and target them with glass pipettes 1/100th the width of a human hair and record electrical currents they use to communicate with other nerve cells.The CB1 cells act like brakes, slowing down activity in a brain region called the nucleus accumbens, which governs emotion and motivation.