Visualization of brain areas provides new learning opportunities along with increased understanding of how interconnected the brain is. New research published in the journal Frontiers in Neuroanatomy, sought to improve current 3D brain atlases (Kiwitz et al., 2022). Currently, there are no 3D maps of the lateral (LGB) and medial geniculate body (MGB) that are of the resolution or completeness that this research offers. This research was able to establish consistent representations of the LGB and MGB, along with subdivisions of both, based on analysis of 10 postmortem brains with improved resolution (Kiwitz et al., 2022). Being able to visualize these thalamic areas with such detail allows for more in-depth study of brain disorders and functional impairments.

The thalamus is a major relay center in the brain and conducts many sensory and motor inputs to all different areas of the brain. Within the thalamus are several different nuclei, each performing a different role (Torrico & Sunil Munakomi, 2021). The lateral geniculate body (LGB), a thalamic nucleus mapped in this research, acts as a relay station for signals coming from the eye carrying visual information (Millodot, 2018). Damage to the LGB can cause visual loss so understanding LGB cellular function and connectivity is vital for research aimed at restoring loss of vision (Yu et al., 2018).

The medial geniculate body (MGB) is also a thalamic nucleus but instead of visual information, the MGB acts as a relay station for auditory inputs (Gray & Recanzone, 2017). Signals from the MGB are sent to the auditory cortex (Chen et al., 2019). Damage to the MGB can result in lack of sound which makes this an important structure to understand for auditory research and treatment fabrication localization (Kelly & Judge, 1985). While mapping the MGB, this study divided the MGB into three subdivisions based on construction and composition (Kiwitz et al., 2022).  

To create a successful 3D high resolution map, researchers used ten human brains from body donors, all of which consented prior to passing, and used stained brain sections to visualize cellular composition (Kiwitz et al., 2022). Brain tissue was preserved for a three month minimum period and then, with magnetic resonance imaging (MRI), a spatial reference for 3D reconstruction was created (Kiwitz et al., 2022). Brains were sliced into small sections (20 µm thickness) and every 15^th section was stained for cell bodies with a silver staining technique, then digitized via scanners (Kiwitx et al., 2022). 

Based upon the combined anatomy of the 10 postmortem brains, an organizational map of the thalamus was created. Exact positions and boundaries of regions within the thalamus were identified and mapped. The map created not only offers a new 3D compositional view based on multiple brains, but an entire reference guide of the thalamic areas, down to the individual cells was created. The results of the 3D map created not only act as a reference guide but lay foundational work in identifying regional connectivity and the ability to localize brain disorders. Because the LGB is highly involved in the visual field and eye movements, and the MGB is involved in auditory processing, this map offers the basis to localize visual and hearing deficits/disorders. Postmortem analysis and mapping of brain tissue has countless implications on future research in brain communication and disorders; the study of postmortem brain tissue leaves countless tales to be told.      

[+] References

[+] Other Work By Chandler Fanning