The lateral habenula has recently been implicated in encoding anti-reward signals during moments of disappointment. Specifically, the lateral habenula has been shown to inhibit dopamine neurons in the reward system. However, its relationship to the basal ganglia, a major input to the lateral habenula, remains unclear. Recent models have proposed that the basal ganglia may serve as the driving force behind increased habenular activity despite the basal ganglia's primarily inhibitory nature. Here, we report that these inputs to the lateral habenula are, in fact, excitatory and behaviorally aversive. Moreover, we also show that serotonin, a neuromodulator associated with depression, presynaptically modifies inputs from the globus pallidus. However, more research is needed for higher resolution of the synaptic and behavioral aspects of basal ganglia input