Disrupted myeloarchitecture accompanying anatomical abnormalities in the auditory pathway of reeler mice.

Reelin plays a crucial role in neuronal migration and synaptic organization during brain development. Mice lacking Reelin (reeler mice) exhibit severe disorganization in cortical and cerebellar structures. Given that reeler mice show abnormal auditory brainstem responses, we investigated the cytoarchitecture and myeloarchitecture of major relay nuclei in the central auditory pathway. By Kluver-Barrera staining and Bielschowsky staining, we analyzed the primary auditory cortex, medial geniculate body, inferior colliculus, superior olivary nucleus, nucleus of the trapezoid body, and cochlear nucleus in reeler and wild-type mice. We observed marked structural abnormalities across multiple levels of the auditory pathway in reeler mice. These findings suggest that Reelin is essential for the proper structural development of auditory relay nuclei, and that its absence leads to widespread anatomical disorganization across both cortical and subcortical auditory regions. This structural disarray likely underlies the functional auditory deficits observed in reeler mice and underscores the critical role of Reelin in the formation of central auditory circuits.