, 2001, Jones et al., 2002, Seriès et al., 2003, Ozeki et al., 2009 and Adesnik et al., 2012), and this suppression is more pronounced when using natural surround images than when using their phase-scrambled versions Metformin devoid of complex structure (Guo et al., 2005). Visual circuits are thus particularly sensitive to integrating salient image components across natural scenes, which may contribute to contour integration and “pop-out” phenomena at the perceptual level (Knierim and van Essen, 1992). Concomitantly, surround modulation by natural images alters the firing

rate distribution of individual neurons, whereby their responses become more selective and sparse (Vinje and Gallant, 2000, Vinje and Gallant, 2002 and Haider et al., 2010). Sparse codes are considered efficient, because they are able to transfer more information with fewer spikes (Olshausen and Field, 2004). Taken together, surround modulation contributes to contextual processing of sensory information and increases

the efficiency of neural representations for natural scenes (Sachdev et al., 2012). How do neural circuits Sunitinib become specialized to integrate and efficiently represent information from complex natural scenes, which contain image features that extend beyond the RF of any individual neuron? Neurons in V1 are feature selective already at eye opening (Hubel and Wiesel, 1963, Blakemore and Van Sluyters, 1975, Chapman and Stryker, 1993, Krug et al., 2001, White et al., 2001, Rochefort et al., 2011 and Ko et al., 2013). However, little is known about the development of surround modulation and its dependence on early sensory experience, and how this impacts the ability to encode complex natural scenes. Surround

modulation is mediated by excitatory and inhibitory interactions at different stages of the mature visual pathway, including the retina (Olveczky et al., 2003 and Solomon et al., 2006) and visual cortex (Stettler et al., 2002, Angelucci and many Bressloff, 2006, Girardin and Martin, 2009, Ozeki et al., 2009, Haider et al., 2010, Adesnik et al., 2012, Nienborg et al., 2013 and Vaiceliunaite et al., 2013). Since both excitatory and inhibitory circuits refine after eye opening (Frégnac and Imbert, 1984, Katagiri et al., 2007, Kuhlman et al., 2011 and Ko et al., 2013) and are susceptible to changes in visual experience (Ruthazer and Stryker, 1996, Zufferey et al., 1999, White et al., 2001, Chattopadhyaya et al., 2004 and Maffei et al., 2004), the effectiveness of surround modulation may be expected to change during postnatal development. The extent to which this may improve the processing of full field natural scenes is, however, unknown. In this study, we show that circuits mediating surround modulation require sensory experience to become preferentially sensitive to natural stimulus statistics across the RF and its surround.