title: Efferent projections of the superior olivary nucleus in the frog, Rana catesbeiana.
abstract: Following electrolytic lesions of the superior olivary nucleus (SO) of the bullfrog, Rana catesbeiana, the efferent pathways of this nucleus were studied with silver impregnation methods. The major projection was to the ipsilateral principal nucleus of the torus semicircularis. Less conspicuous degeneration was traced to the nuclei magnocellularis and commissuralis of the torus. No contribution was made to the tectum or nucleus isthmi. Other projections of the SO include a sma-ler contralateral projection to these same nuclei and to the ipsilateral nucleus lateralis profundus mesencephali. A system of connections between the acoustic nuclei was invariably interrupted with these lesions and the degeneration seen in the more dorsal acoustic areas was not entirely due to the destruction of SO neurons.
mesh_terms: D000818:Animals; D001306:Auditory Pathways / Q000033:anatomy & histology; D004525:Efferent Pathways / Q000033:anatomy & histology*; D009410:Nerve Degeneration; D009476:Neurons, Efferent / Q000473:pathology; D009847:Olivary Nucleus / Q000033:anatomy & histology*; D011892:Rana catesbeiana / Q000033:anatomy & histology