This study evaluates and compares the release of the neurotransmitter γ-aminobutyric acid (GABA) induced by methanolic extracts obtained from roots of wild plants and from cell suspension cultures of W. americana Linn. The release of this neurotransmitter was evoked by crude and fractioned extracts derived from both roots of wild plant and cell suspension cultures, tested at three concentrations: 10, 50 and 100 µg/ml by means of in vitro incubation of slices of mouse cerebral cortex. Firstly, crude extracts from wild plant roots obtained by applying solvents of different polarities (n-hexane, dichloromethane and methanol) were tested at a concentration of 10 µg/ml with no observed effect on the level of GABA release, but when the same extracts at a concentration of 100 µg/ml was evaluated, methanol extract (MeOH) was determined to be the most effective in terms of the release of GABA . The results suggest that wild plant and cell suspension cultures of W. americana produce some compounds that cause an increase in the release of GABA in in vitro experiments, corroborating with the ethnomedical applications associated with this species, and indicates high potential for research and development of new active drugs for the treatment of several central nervous system (CNS) disorders related to the GABA system.