Introduction: alcohol is a psychotropic depressant of the central nervous system (CNS) that promotes simultaneous changes in several neuronal pathways, exerting a profound neurological impact that leads to various behavioral and biological alterations. Objectives: to describe the effects of alcohol on the CNS, identifying the signaling pathways that are modified and the biological effects resulting from its consumption. Methods: a literature review was conducted and articles published in different languages over the last 15 years were retrieved. Results: the studies reviewed describe the direct effect of alcohol on several neurotransmitter receptors (gamma-aminobutyric acid [GABA], glutamate, endocannabinoids AEA and 2-AG, among others), the indirect effect of alcohol on the limbic and opioid systems, and the effect on calcium and potassium channels and on proteins regulated by GABA in the hippocampus. Discussion and conclusion: the multiple actions of alcohol on the CNS result in a general effect of psychomotor depression, difficulties in information storage and logical reasoning and motor incoordination, in addition to stimulating the reward system, a fact that may explain the development of addiction. Knowledge on the neuronal signaling pathways that are altered by alcohol allows the identification of effectors which could reduce its central action, thus, offering new therapeutic perspectives for the rehabilitation of alcohol addicts.