The goal of this project was to elucidate the role of Median Raphe (MnR) Vglut3+ neurons in complex associative learning. While hippocampal regions such as CA1 are known to contribute to learning, the influence of MnR inputs, particularly Vglut3+ projections to the hippocampus, remains poorly understood. This question was investigated using viral-mediated knockdown of Vglut3 in the MnR and the impact on learning was assessed through behavioral training. The preliminary results show that Vglut3 knockdown has no effect on the avarage scores on the learning task, although it does lead to a significantly greater variation in the aqusition rate between mice.