Fig. 5: Schematic representation of coordinated effects of optogenetic activation of CG feedback.

Without LED activation of CG feedback, magnocellular LGN neurons exhibit extraclassical surround suppression (dark blue depression) and prefer slightly lower spatial frequency gratings; with LED activation of CG feedback (inset top right), recorded magnocellular neurons exhibit increased surround suppression (deeper dark blue depression), have smaller classical receptive fields with larger response amplitude (narrower and taller central peak), and thus prefer higher spatial frequency gratings.