Objective      To compare the expression of endogenous cannabinoid receptor 1 (CB1) in human and mouse retinal ganglion cells and observe the modulation of CB1 receptor agonist WIN55212-2 to γ-aminobutyric acid (GABA) currents.       Methods      Immunofluorescence assay was applied to study the expression pattern of CB1 receptors in the retina. Whole-cell patch-clamp technology was used to record GABA currents in the retinal ganglion cells after applying 2 μmol/L WIN55212-2 or 2 μmol/L WIN55212-2+4 μmol/L SR141716A (CB1 receptor antagonist).       Results      CB1 receptors were expressed in the human outer nuclear layer

inner nuclear layer and ganglion cell layer

while expressed in the mouse inner plexiform layer and outer plexiform layer. The patch-clamp recording results showed that WIN55212-2 significantly reduced the GABA current amplitude in the human and mouse retinal ganglion cells(P0.05). The application of WIN55212-2 resulted in significant changes of GABA current kinetics

including low reaction speed

long current peak time and short recovery time

in human retina

but not in mouse retina (P0.05).       Conclusion      CB1 receptors are expressed abundantly and differentially in the  human and mouse retina

and have different effects on the GABA currents in the retinal ganglion cells. WIN55212-2 suppresses the GABA current amplitude in the human and mouse retinal ganglion cells

but modulates the GABA current dynamics only in human retinal ganglion cells.