Fig. 5

TL is the site of binocular integration. A Maximum projection image acquired from a 7dpf Tg(hspGGFF23C,uas:gcamp6s,uas:mcherry) triple transgenic larva. Note labeled cell bodies in TL and axonal plexus in OT. B Coronal view of green bracketed region in A. Note that axons from TL target the SM layer, directly beneath the skin overlying the tectum. C Magnified view of white bracketed region in B (mcherry channel only). Arrowheads denote SMTL neurons with axons extending into ipsilateral OT. D ON, OFF, and DUAL response classes identified in hspGGFF23C+ SMTL neurons. E Comparison of response class distribution in id2b+ PyrNs and hspGGFF23C+ SMTL neurons. Note greater proportion of ON responsive units among hspGGFF23C+ TL neurons. Two-way ANOVA, interaction effect p<0.0001, with posthoc unpaired t tests. F Comparison of response onset (LUX at half-max) in PyrNs and SMTLs in response to 10s ramp stimulus. Two-way ANOVA, interaction effect p=0.9317, with posthoc unpaired t tests. G Comparison of response duration (width at half-max) in PyrNs and SMTLs in response to 10s ramp stimulus. Two-way ANOVA, interaction effect p=0.989, with posthoc unpaired t tests. Note: for t test comparisons in E–G only p values that reached significance are shown. H Magnified view of anterior TL in a left eye-enucleated 7dpf Tg(hspGGFF23C,uas:gcamp6s) larva. Upon stimulus presentation to the right (intact) eye, three SMTLs in right TL exhibited visual responses (1–3). I Responses in SMTL neurons 1–3 in H during presentation of 10s ramp stimulus to the right (intact) eye. Note that the three neurons exhibited consistent responses to each ramp cycle. J Quantification of percent of SMTLs in left and right TL of enucleated larvae that responded during 10s ramp stimulus presentation to the right (intact) eye. N = 12 larvae, paired t test. Scale bar: 60μm in B, C, 30μm in D, and 20μm in K