__________________________Thakkar's earlier research showed that nicotine combined with alcohol stimulates what he calls the "reward center" of the brain. However, the new study shows a dependent relationship between the substances._________________________Thakkar早期的研究显示,尼古丁再加上酒精可以刺激他所谓的大脑"奖励中心",但是,最新的研究显示两种物质间彼此间的依赖性.