“…Mouse extrastriate cortex also differs from that in many nonprimate species (i.e., quoll, hedgehog, guinea pig, rabbit, flying fox, opossum, squirrel, tree shrew, cat) in which V1 is adjoined on the lateral side by a single area, V2 (Kaas et al, 1970(Kaas et al, , 1989Hall et al, 1971;Towns et al, 1977;Payne, 1993;Rosa, 1999;Kahn et al, 2000), and therefore has a "simple" organization . However, mouse extrastriate cortex is similar to that in species with a "simple" organization, in that V1 is adjoined on the medial side by parastriate or splenial visual areas, which in hedgehog, rat, hamster, degu, guinea pig, and cat receive direct V1 input and contain visually responsive neurons (Kalia and Whitteridge, 1973;Choudhury, 1978;Gould and Ebner, 1978;Olavarria and Mendez, 1979;Bravo et al, 1990;Olavarria and Montero, 1990;Spatz et al, 1991;Montero, 1993). Thus, mouse extrastriate cortex is "simple" in the sense that it has a single V2-like area, LM, on the lateral side of V1, but is "complex" in that lateral V1 is adjoined by multiple visual areas.…”