Summary Proprioception, the sense of limb and body position, is essential for generating proper movement. Unconscious proprioceptive information travels through cerebellar-projecting neurons in the spinal cord and medulla. The progenitor domain defined by the basic helix-loop-helix (bHLH) transcription factor, ATOH1, has been implicated in forming these cerebellar-projecting neurons; however, their precise contribution to proprioceptive tracts and motor behavior is unknown. Significantly, we demonstrate that Atoh1-lineage neurons in the spinal cord reside outside Clarke’s column (CC), a main contributor of neurons relaying hindlimb proprioception, despite giving rise to the anatomical and functional correlate of CC in the medulla, the external cuneate nucleus (ECu), which mediates forelimb proprioception. Elimination of caudal Atoh1-lineages results in mice with relatively normal locomotion, but unable to perform coordinated motor tasks. Altogether, we reveal that proprioceptive nuclei in the spinal cord and medulla develop from more than one progenitor source suggesting an avenue to uncover distinct proprioceptive functions.

treatment, depth of invasion, tumor differentiation, lymphatic invasion, vascular invasion, tumor budding, polypoid/non-polypoid growth, adenoma component, and lymph node metastasis. Pathologically diagnosis of massive invasion was judged according to Kudo's classification of the degree of submucosal invasion. Their morphology (gross appearances) were divided into protruded, flat-elevated, and depressed type. Results: The incidence of small T1 cancers was 15.5% (179/1153). 'Small' group had significantly more depressed-type lesions('Small' 46.9% vs. 'Large' 20.1%, p<0.01), significantly lower adenoma component ('Small' 29.0% vs. 'Large' 42.6%, p<0.01) and polypoid growth ('Small' 46.4% vs. 'Large' 64.9%, p<0.01) than 'Large' group. Concerning initial treatment, 'small' group was significantly more likely to undergo endoscopic treatment, whilst the lymph node metastasis rate was not significantly different between the two groups('Small' 12.4% vs. 'Large' 10.8%, pZ0.64). Conclusion: Although 'small' T1 cancers tended to be adopted to initial endoscopic treatment, nodal metastasis rate showed no differences between 'small' and 'large'. In addition, 'small' T1 cancers contain more depressed-typed tumors. It is therefore important to take more careful assessment even when we find a 'small' lesion. And we have to do endoscopy so as not to miss any 'small' lesions.

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