Fig. 6

Direct cortical activation in visually naïve ferrets produced an increase in direction selectivity. a Engineered viruses that cause the expression of Channelrhodopsin-2 were injected in young ferrets several days before eye opening. b Initial orientation and direction selectivity were assessed with visual stimuli. c Next, the visual display was switched off and patterned light was shone on the cortex to produce specific activity patterns for several hours. d Periodically, the visual display was switched on and orientation and direction selectivity were assessed with visual stimulation. We found that 9 h of this direct cortical stimulation protocol resulted in an increase in cortical direction selectivity [40]. Adapted from [40]