Myeloarchitecture

Myeloarchitecture refers to the pattern and organization of myelin in the nervous system, especially in the cerebral cortex and major white matter tracts. It reflects the distribution of myelinated axons, their conduction properties, and connectivity.

In the cerebral cortex, myeloarchitecture is used to distinguish areas based on differential myelin density and fiber orientation. Classic examples include densely myelinated primary sensory and motor regions and, in some species, the stripe of Gennari in the primary visual cortex. Myeloarchitectonic maps complement cytoarchitectural maps in delineating cortical areas.

Throughout the central nervous system, myeloarchitecture is shaped by development and experience; myelination follows a stereotyped sequence, accelerating conduction and timing across circuits. Myelinated tracts in the white matter form organized fasciculi with distinct trajectories that underlie functional networks.

Clinical relevance: Demyelinating diseases and aging alter myeloarchitecture, changing histological appearance and diffusion properties. In vivo imaging techniques such as magnetization transfer MRI, myelin water fraction, and diffusion MRI provide indirect measures of myelin integrity and help map white matter maturation and pathology.

Study methods include histological staining for myelin (e.g., Luxol fast blue) and histomorphometric analysis, as well as modern noninvasive imaging and the use of myeloarchitectural atlases to interpret brain structure and connectivity.