a, Peak SuperClomeleon FRET- and YFP-control responses to light stimuli (50 ms, 0.1 Hz) delivered to the eye contralateral to the recorded LGN (n > 90 trials from 3 mice for SuperClomeleon and from 4 mice for YFP, ***P < 0.001, Friedman test). b, Chloride photometry transients are sensitive to the GABA A receptor antagonist flumazenil in a dose-dependent manner. Left, intraperitoneal injection of 15 mg kg–1 flumazenil resulted in a 90% peak reduction of light-evoked chloride photometry responses, which recovered over the course of 90–100 min as predicted by flumazenil pharmacokinetics. Insets show example traces of single events recorded during baseline, peak suppression and recovery. Right, quantification of the maximal suppressive effects and recovery of 5 mg kg–1 and 15 mg kg–1 flumazenil on chloride photometry responses (n> 90 trials from 3 mice, *P < 0.05, **P < 0.01, Friedman test). c, Cumulative distributions of unitary visual-evoked SuperClomeleon FRET peaks in response to light stimuli in the cross-modal task. Under baseline conditions, ‘attend to audition’ trials exhibited significantly larger amplitudes than ‘attend to vision’ trials, consistent with average data in Fig. 5f. Optogenetic silencing of visTRN neurons eliminated the difference between trial types and resulted in peak amplitudes comparable to baseline ‘attend to vision’ trials (n = 3 mice, P < 0.005 for ‘attend to audition’ trials vs all other trial types, Kolmogorov–Smirnov statistics with Bonferroni correction). d, Combined optogenetic and chloride photometry inactivation of different frontal cortical regions in the LGN while mice performed the cross-modal task. Only PL inactivation eliminates differential inhibition between visual and auditory trials (n = 6 mice, ***P < 0.001, Wilcoxon rank-sum test).