Striatal dopamine (DA) and acetylcholine (ACh) play key roles in reward prediction signalling and goal-directed behaviour. Midbrain DA neurons increase their firing in response to unexpected rewards or reward-predicting cues, while striatal cholinergic interneurons exhibit coincident burst-pause activity. Striatal DA and ACh also reciprocally regulate each other’s release with ACh modulating DA release through axonal nicotinic acetylcholine receptors (nAChRs). Activation of nAChRs can drive DA release but also generate strong short-term depression (STD) of subsequent DA release, not arising from depletion. The mechanisms by which nAChRs depress DA release are not well understood. We tested whether nAChR activation drives STD of DA release by limiting the availability of voltage-gated sodium channels (VGSCs) for re-activation. We monitored striatal DA release and its STD in mouse brain slices using fast-scan cyclic voltammetry and assessed the impact of manipulation of VGSC activity in the presence or absence of nAChR activity. Partial inhibition of VGSCs with low concentrations of tetrodotoxin, or prolongation of VGSCs inactivation using rufinamide, significantly augmented STD of DA release when nAChRs were active but not when nAChRs were antagonised. The augmented STD was not due to changes in ACh release reported by fluorescent sensor GRAB-ACh3.0, nor to indirect effects of GABA circuits as GABA-receptor antagonists did not preclude these effects. We are exploring the direct impact on DA axon membrane potential by imaging voltage sensor ASAP5f at the population level. To date, our data suggest that nAChR activation promotes inactivation of VGSCs on DA axons that contributes to STD.