Fig. 5: Visual and vestibular sources to the oculomotor nucleus.

a Neurobiotin was injected in the oculomotor nucleus (inset), which showed ipsilateral projections from thalamus. b Numerous retrogradely labeled cells were found in pretectum forming a population projecting to the ipsilateral oculomotor nucleus. c Retrogradely neurons in the region of the nMLF. Some retrogradely labeled neurons were also observed in the SNc (arrows). d, e Projections were also found from the two other cranial nerve nuclei responsible for extraocular muscle innervation, illustrated here by a cell population in the trochlear nucleus (d) and contralateral abducens nucleus (e). Retrogradely labeled neurons were also found in the ventral part of the isthmic region, nearby the thick axons labeled from the AON. (d arrows). f a strong projection was confirmed^17,20 from the AON, and retrogradely labeled neurons were also found in dorsal aspects of the OLA. Abbreviations: Th Thalamus, Hyp Hypothalamus, pc posterior commissure, PT Pretectum, ot Optic Tract, nMLF Nucleus of the Medial Longitudinal Fasciculus, SNc, Substantia Nigra Pars Compacta, nIV Trochlear Motor Nucleus, AON Anterior Octavomotor Nucleus, OLA Octavolateral Area, ION Intermediate Octavomotor Nucleus, nVI Abducens Motor Nucleus. Scale bar = 250 µm in a (and inset) and e; 100 µm in b and c; 150 µm in d and f.