Figure 1. Ocular muscle anatomy and the retinofugal projection of the mouse.

A. Vitreal injections of DiI in both eyes reveals the gross form of the retinofugal projection. The overlying cortex and the eyes have been removed from this whole mount fluorescent image. B. Schematic of relevant anatomical features of the retinofugal projection in the mouse. Drawing is with approximately the same perspective and scale as A. C. Schematic showing the pattern of terminations of dorsal, nasal, ventral, and temporal retinal ganglion cell axons in the dorsal and ventral lateral geniculate nuclei (dLGN and vLGN) and contralateral superior colliculus. Axons enter the targets perpendicular to the mediolateral target axes, corresponding to the dosoventral axis of the retina. D. Schematic of muscle insertion points around the globe of the eye. Oblique muscles are very small in rodent and are not considered. The sizes of both the muscle (sectors 1–3 for superior rectus, 7–9 for medial rectus, 13–15 for inferior rectus and 19–21 for lateral rectus) and intermuscle regions (4–6; 10–12; 16–18 and 22–24) are drawn to scale. E, F, G, H. Injection of dye into the four principal muscles leads to spots of label around the perimeter of the superior colliculus. In E, dye was injected into sector 2 of the superior rectus (SR). In F, dye was injected into sector 8 of the medial rectus (MR). In G, dye was injected into sector 15 of the inferior rectus (IR). In H, dye was injected into sector 20 of the lateral rectus (LR). White lines show outline of the superior colliculus. Scale bars in A and E are 1 mm. Scale bar in E applies to E, F, G and H, and medial is to the right, caudal is up in these panels.