Fig. 4.

Schematic drawing of a brain showing the relative locations of the day- and night-vision (cluster N) activated brain regions in night-migrant songbirds. The thamalofugal and tectofugal visual pathways have been determined in other bird species. Upper right, the extent of cluster N seen from the dorsal surface of the brain, determined from serial parasagittal and coronal sections hybridized to ZENK. GLd, lateral geniculate nucleus, dorsal part; Rt, nucleus rotundus; additional abbreviations are as in legend of Fig. 1.