The study of neuroscience has vastly benefited from the use of brain slices. This preparation has been fundamental for the understanding of the cellular basis of nervous system function as well as for the study of the mechanisms involved in neuronal network dysfunction. This experimental model provides flexible access, and control of, specific neural circuits and maintains their basic properties, allowing them to reproduce most of their natural network activities. Brain slices permit the combination of sophisticated techniques such as electrophysiology, fluorescence imaging, pharmacology, molecular biology, etc. More recently, the development of organotypic brain slice cultures has expanded the use of modern technical approaches to the study neuronal networks, while increasing their possibilities of evaluating long-term effects of acute experimental conditions, as well as the effects of chronic treatments on neuronal network function in vitro. Here, I will provide an overview of the use of organotypic cultures to understand neuronal network function and dysfunction, as well as the pharmacological approaches used for these studies. As a final example, I will review the studies performed in organotypic cultures regarding the deleterious effects of long-term amyloid beta application on neuronal networks in vitro, as well as the use of drugs that may prevent or revert their deleterious effects on nervous system function. Overall, this review will provide elements to support the use of organotypic cultures as a very reliable model to explore long-term neuropharmacological studies in vitro.