Fig. 5.

Comparison of the peripheral branches of the trigeminal nerve in wild-type and mutant mice. A, Schematic drawing of an E13.5 embryo (adapted from Theiler, 1989) indicating the plane of section used for the camera lucida analysis. The thin ophthalmic branch (dorsal) and the thick maxillary branch (middle) were compared in wild-type, heterozygous, and mutant mice. The mandibular branch (ventral) travels obliquely to this plane and was not analyzed. ON, Optic nerve. B, Camera lucida drawing showing the ophthalmic and maxillary branches of the trigeminal nerve in a wild-type embryo. The ophthalmic nerve ishatched; the maxillary fascicles arecross-hatched. OX, Optic chiasm.C, Camera lucida drawing of the same complex in a mutant animal. The ophthalmic (hatched) and maxillary (cross-hatched) branches of the ganglion are both depleted (see Table 3). Scale bars, 100 μm.