Injection of AAV5.Syn.GCaMP6s into visually responsive superior colliculus. A, PSTH shows neural responses in medial superior colliculus during a 25ms light flash. Dashed line indicates 99% confidence limit. Mean waveform scale: 1ms, 500 mV. PSTH: 100 trials, 10 ms bin widths. B, Cytochrome oxidase processed coronal section through the superior colliculus. Inset shown in C. C, Fluorescent image of transfected neurons in the deep layers of the medial superior colliculus after injection of AAV5.Syn.GCaMP6s (Penn Vector Core). White arrow denotes injection area where visually responsive neurons were recorded in A.