There have been a small number of previous reports indicating the expression of certain K2P channels in the mammalian retina, most commonly as part of the initial tissue panel screen conducted following cloning of the specific channel subunits. For example, expression of TRAAK in the mouse retina has previously been confirmed by RT-PCR and in situ hybridisation63 whereas RT-PCR and immunohistochemistry indicate expression of TWIK-3 (previously termed TWIK-2) in the ganglion cell layer of the mouse retina64. However, in both cases the specific cell types expressing these channels has not been determined. A further report has indicated that TASK-2 (a TALK type channel) is expressed in the majority of ganglion cells and both dopaminergic and cholinergic amacrine cells of the rat retina65. Our data are largely consistent with these previous reports. In agreement with Fink et al.63, TRAAK was identified in the mouse retina, although we now confirm this expression is largely restricted to Müller cells with lower levels of expression detected for RGCs. We also confirm that TWIK-3 is expressed within RGCs as previously indicated64. However, contrary to previous reports in the rat retina, we did not detect TASK-2 in the adult mouse retina using either qPCR or immunostaining methods. We did however detect TASK-2 mRNA in the postnatal mouse retina, potentially indicating different roles for TASK-2 in the mouse and rat retina. In addition to validating these earlier studies, our data show that the expression of K2P channels in the mammalian retina is highly complex with multiple K2P channels detected within RGCs and Müller cells.