The goal is to investigate whether the light induced modification of mitral cell firing is due to the activity of neuronal opsins (encephalopsin), whose action is mediated by G-proteins activation. For this reason light effects are investigated in the presence of 2 mM of the non-hydrolyzable GDP analog Guanosine 5′-[β-thio]diphosphate trilithium salt (GDPβS), a G protein inhibitor.
The result shows that blocking G-protein activation does not prevent light reduction of MC firing.