The use of herbicides is a growing practice worldwide, especially for weed control in genetically modified crops. In Argentina, herbicides such as glyphosate and glufosinate-ammonium (GLA) -an irreversible glutamine synthase inhibitor- are widely used. Following the emergence of crop resistance to other herbicides such as glyphosate, there has been a growing trend toward the use of glufosinate-ammonium. Different studies have shown toxic effects on developmental nervous system in humans and animals after GLA exposure. Our study was based on evaluating developmental toxicity in Wistar rats exposed to GLA formulation at doses equivalent to 20, 40 and 60 mg/kg of GLA from postnatal day 7 to 27, and subjected to behavioral tests to evaluate motor activity and cognitive functioning. Weight evolution was also carried out and the preliminary result showed a delay in the growth and development of neonates exposed to the highest doses. Moreover, studies in hippocampal pyramidal neurons cultured for 24 and 48 hours were performed. Immunocytochemical studies revealed that undifferentiated neurons exposed to GLA showed alterations on their development since shorter and less complex dendritic tree was observed compared to controls. Together, our observations suggest that GLA exposure induce neurotoxicity signs during development.