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The course and innervation system of the hypoglossal nerve in the syringeal muscles of the Jungle crow (Corvus macrorhynchos) Naoki Tsukahara, Masato Aoyama, Shoei Sugita School of Agriculture, Utsunomiya University, Japan The syrinx has many syringeal muscles that are closely related to the vocalization in Avian. The syringeal muscles are controlled by the hypoglossal nerve (NXIIts) that is originated from the hypoglossal nucleus (nXIIts). Jungle crows can make many types of vocals, therefore their syringeal muscles and its regulation by the nXIIts can be more complex than those in other birds. The aim of this research was to clarify the morphological and histological aspects of the control system of the syringeal muscles by the nXIIts. Firstly, an anatomical study of the course of the NXIIts in Jungle crows was conducted. As a result, the NXIIts branched out into several nerves from main trunk of NXIIts at the level of the syrinx and ended complexly in the syringeal muscles. Secondly, the projection system to the syringeal muscles from the nXIIts was investigated by the injection of horseradish peroxidase into the syringeal muscles. As a result, some syringeal muscles were controlled by bilateral hypoglossal nuclei, with ipsilaterally predominance. 
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