High Resolution MRI of the LGN's Two Compartments

Article: Charting hidden territory of the human brain
Source: Technical University of Dresden (Germany)
Published: October 8, 2021 

High spatial resolution MRI showing differences
in myelin content in the two LGN compartments (top),
and aggregate imaging data of LGN location (middle)

The thalamus is a relay station connecting sensory input to different regions of the brain. The visual sensory thalamus is a region that connects the eyes to the brain, with several nuclei that are involved in visual processing. The lateral geniculate nucleus (LGN) of the visual sensory thalamus, a nucleus that is most relevant to visual processing, contains two compartments, which are characterized by different amounts of white matter (myelin). Thus far, it has been difficult to assess these two compartments, because they are small and located deep within the brain. Neuroscientists in Germany are investigating a new noninvasive imaging method known as structural quantitative MRI (qMRI) using a specialised MRI machine with unprecedented high spatial resolution. By coincidence, a doctoral student noticed structures that she thought might resemble the two LGN compartments in neuroimaging data. She followed up the discovery with imaging of 27 participants with the 7 Tesla in-vivo qMRI and studying ultra-high resolution 7 Tesla qMRI of one post-mortem human LGN specimen. Along with histological confirmation, the results showed that differing amounts of white matter can be detected on the high resolution MRI images, demonstrating that this new imaging technique can be used to investigate the two compartments of the lateral geniculate nucleus in living humans. First author of the study comments, “The finding that we can display visual sensory thalamus compartments in living humans is fantastic, as it will be a great tool for understanding visual sensory processing both in health and disease in the near future."

My rating of this study: ⭐⭐⭐

Müller-Axt C, Eichner C, Rusch H, et al. "Mapping the human lateral geniculate nucleus and its cytoarchitectonic subdivisions using quantitative MRI." NeuroImage.  244:118559. 1 December 2021. https://doi.org/10.1016/j.neuroimage.2021.118559