There is now substantial evidence that kisspeptin acts exclusively through Gpr54 to stimulate GnRH neurons. However, given the widespread brain distribution of kisspeptin and Gpr54 and the mismatch between kisspeptin and Gpr54 in some brain areas, it is likely that these molecules modulate a range of physiological processes via other receptor(s). The nature of kisspeptin and Gpr54 signaling at these other sites has received little attention. It was recently shown that kisspeptin can directly and indirectly act to excite and inhibit, respectively, the electrical activity of neurons located in the arcuate nucleus (ARN) (Fu & van den Pol, J Neurosci, 2010). Here we tested kisspeptin actions on ARN neurons in wildtype and Gpr54 knockout mice using acute brain slices and the electrophysiology. Cell-attached recordings of GnRH neurons revealed potent stimulatory actions of kisspeptin on GnRH neurons in control mice (GnRH-GFP; Gpr54+/+) but no effects in GnRH neurons in GnRH-GFP; Gpr54-/- (Gpr54KO) mice. In the ARN of control mice approximately one third of neurons were either excited on inhibited by 100-400nM kisspeptin. Surprisingly, ARN neurons of Gpr54KO mice exhibited the same responses demonstrating that kisspeptin acts independently of Gpr54 in the ARN. The effects of kisspeptin were direct on ARN neurons and replicated by RFRP3 in the majority of cases. This suggests that kisspeptin may act through NPFF receptors to modulate the electrical activity of ARN neurons.