Following qPCR analysis, immunohistochemistry was performed with anti-K2P channel antibodies to confirm the expression and localisation of K2P channel proteins within the mouse retina. Overall our data show that TWIK-type, TREK-type and TASK-type channels are widely expressed in the mouse retina, with the highest levels of expression detected within retinal ganglion cells (TASK-1, TREK-1, TWIK-1, TWIK-2, TWIK-3, and to a lesser extent TREK-2, TRAAK, and TRESK) and Müller cells (TWIK-1, TASK-3, TRAAK, and TREK-2) (Figs 2, 3, 4, 5, 6, results summarised in Table 1).