Consistent with previous results40,41, somatic fluorescence changes in GABAergic neurons were broadly tuned with respect to stimulus orientation (Fig. 6a, b; Supplementary Fig. 12). However, their dendrites showed pronounced orientation-tuned domains (Fig. 6c, d). Individual dendritic branches often had multiple domains with distinct preferred orientations, consistent with the diverse preferences of inputs to GABAergic neurons42,43. The underlying fluorescence responses were modulated at the temporal frequency of the drifting grating (1 Hz) (Fig. 6e), a characteristic feature of V1 excitatory neurons in the superficial layers of V130, suggesting that the responses reflect local excitatory synaptic input. Tuned dendritic domains were seen in parvalbumin-positive (Fig. 6) and somatostatin-positive (data not shown) interneurons.
