Fig. 3: Polarised light imaging in BigMac.
From: An open resource combining multi-contrast MRI and microscopy in the macaque brain
The colours correspond to orientations described by the 2D colour wheel in image (iv). Note, this is different from the standard 3D colour representation in diffusion MRI. a Example PLI throughout the brain. Image 1 = most anterior, 8 = most posterior of the images shown. The myeloarchitecture is viewed in great detail due to the 4 μm / pixel PLI resolution. We observe fibres projecting into the cortex (right hand panel part (i)), into and through subcortical structures (ii), around the pons (iii) and across the cerebellum (iv). Inset (i) comes from image 8, (ii) from image 3, (iii) from image 4 and (iv) from image 6. In D, the blue arrows point to the gyri crown. b We hypothesise that the PLI signal in the cerebellar molecular layer can be attributed to parallel fibres. b (left) The yellow and green arrows point to the granular layer and the molecular layer respectively. b (right) The structure of the cerebellar cortex. This highly simplified schematic focuses solely on the granule and Purkinje cells, to illustrate the parallel fibres in the molecular layer. Note, the dendritic tree of the Purkinje cells has highly anisotropic dispersion. Here we see the axis of least dispersion, where the Purkinje dendritic tree fans out most in the through-page orientation. PLI were acquired for 192 slides throughout the brain.
