In the study, researchers trained rats to associate either a white or black room with a dose of alcohol or cocaine. After they were conditioned, rats always chose the color room associated with their addicted substance. The researchers wanted see if they could break the cycle by giving the rats a drug called isradipine, which blocks the transmission of calcium ions to cells in the body. While isradipine is primarily prescribed to lower blood pressure, other studies have indicated that it may also make the brain more plastic and able to be rewired.