Neurons communicate with each other through the release of chemical neurotransmitters. Drugs and alcohol can alter the release and uptake of neurotransmitters, thus changing our reactions and perceptions. For example, alcohol inhibits neuron function of the brain and poisons other organ systems, such as the liver. Cocaine changes the release of “feel-good” neurotransmitters. This results in dependency and elevated feelings of pleasure that can lead to addiction.