Fig. 4.

Cortical representation of sensory stimuli in slightly sedated mice. (a) Cortical responses to bilateral visual stimulation (200-ms horizontal moving grating) in a transgenic mouse expressing VSFP Butterfly 1.2 in layer II/III pyramidal population. (a1): $\mathrm{\Delta }R/R$ snapshot showing peak depolarizing response in both visual cortices following binocular sensory stimulation. (a2): Ratiometric depolarizing responses from the left and right visual cortex ROIs, averaged across 40 trials ($\pm \mathrm{SEM}$). (b) Cortical response to right whisker stimulation (20 ms air puff to whole trimmed whisker field) in a transgenic mouse expressing chimeric VSFP Butterfly in pyramidal neurons across all cortical layers. (b1): $\mathrm{\Delta }R/R$ snapshot showing peak depolarizing response in the contralateral somatosensory cortex following sensory stimulation. (b2): Ratiometric depolarizing response from the contralateral and ipsilateral somatosensory ROIs, averaged across 50 trials ($\pm \mathrm{SEM}$). Fast depolarizing response is initially observed in the contralateral ROI, and subsequently in the ipsilateral ROI with a minor delay. Gray dotted lines demark time period represented by the snapshot shown in b1. Note that the ipsilateral response appears only in the subsequent frame. Note that the different response timescales in (a) and (b). Mice are sedated. These data were collected as described in Akemann et al.¹¹ and Carandini et al.¹⁴