Histology-informed automatic parcellation of white matter tracts in the rat spinal cord.

The white matter is organized into "tracts" or "bundles," which connect different parts of the central nervous system. Knowing where these tracts are located in each individual is important for understanding the cause of potential sensorial, motor or cognitive deficits and for developing appropriate treatments. Traditionally, tracts are found using tracer injection, which is a difficult, slow and poorly scalable technique.

Hydrogel Mechanics Influence the Growth and Development of Embedded Brain Organoids.

Brain organoids are three-dimensional, tissue-engineered neural models derived from induced pluripotent stem cells that enable studies of neurodevelopmental and disease processes. Mechanical properties of the microenvironment are known to be critical parameters in tissue engineering, but the mechanical consequences of the encapsulating matrix on brain organoid growth and development remain undefined. Here, Matrigel was modified with an interpenetrating network (IPN) of alginate, to tune the mechanical properties of the encapsulating matrix.

Midbrain organoids with an gene triplication model key features of synucleinopathy.

, the first gene associated with Parkinson's disease, encodes the α-synuclein protein, the predominant component within pathological inclusions termed Lewy bodies. The presence of Lewy bodies is one of the classical hallmarks found in the brain of patients with Parkinson's disease, and Lewy bodies have also been observed in patients with other synucleinopathies. However, the study of α-synuclein pathology in cells has relied largely on two-dimensional culture models, which typically lack the cellular diversity and complex spatial environment found in the brain.

Construction of a rat spinal cord atlas of axon morphometry.

Atlases of the central nervous system are essential for understanding the pathophysiology of neurological diseases, which remains one of the greatest challenges in neuroscience research today. These atlases provide insight into the underlying white matter microstructure and have been created from a variety of animal models, including rats. Although existing atlases of the rat spinal cord provide some details of axon microstructure, there is currently no histological dataset that quantifies axon morphometry exhaustively in the entire spinal cord.

Axons morphometry in the human spinal cord.

Due to the technical challenges of large-scale microscopy and analysis, to date only limited knowledge has been made available about axon morphometry (diameter, shape, myelin thickness, volume fraction), thereby limiting our understanding of neuronal microstructure and slowing down research on neurodegenerative pathologies. This study addresses this knowledge gap by establishing a state-of-the-art acquisition and analysis framework for mapping axon morphometry, and providing the first comprehensive mapping of axon morphometry in the human spinal cord. We dissected, fixed and stained a human spinal cord with osmium tetroxide, and used a scanning electron microscope to image the entirety of 23 axial slices, covering C1 to L5 spinal levels.