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Bennett, D. L.

Publications and source records attributed to Bennett, D. L..

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StereoMate: A Stereological and Automated Analysis Platform for Assessing Histological Labelling in Cleared Tissue Specimens

Tissue clearing methods offer great promise to understand tissue organisation, but also present serious technical challenges. Generating high quality tissue labelling, developing tools for demonstrably reliable and accurate extraction, and eliminating baises through stereological technique, will establish a high standard for 3D quantitative data from cleared tissue. These challenges are met with StereoMate, an open-source image analysis framework for immunofluorescent labelling in cleared tissue. The platform facilitates the development of image segmentation protocols with rigorous validation, and extraction of object-level data in an automated and stereological manner. Mouse dorsal root ganglion neurones were assessed to validate this platform, which revealed a profound loss and shift in neurone size, and loss of axonal input and synaptic terminations within the spinal dorsal horn following their injury. In conclusion, the StereoMate platform provides a general-purpose automated stereological analysis platform to generate rich and unbiased object-level datasets from immunofluorescent data.

neuroscience

Human Handedness: Genetics, Microtubules, Neuropsychiatric Diseases and Brain Language Areas

BackgroundThe skew in distribution of handedness is a uniquely human trait, and has fascinated researchers for centuries. The heritability of handedness is estimated at 25%, but defining genetic variants contributing to this trait has so far proved elusive.\n\nMethodsWe performed GWAS of self-reported handedness in UK Biobank, a prospective cohort study of [~]500,000 individuals. Furthermore, we investigated correlations between our associated SNPs and brain imaging-derived phenotypes (IDPs) from >9,000 individuals in UK Biobank, as well as between self-reported handedness and IDPs.\n\nResultsOur association study of 38,322 left-handers vs 356,567 right-handers (excluding ambidextrous participants) revealed three genome-wide significant loci (rs199512, 17q21.31, p=4.1x10-9; rs45608532, 22q11.22, p=1.4x10-8; rs13017199, 2q34, p=3.3x10-8). In the imaging study, we found strong associations between rs199512 and diffusion MRI measures mainly in white matter tracts connecting language-related brain regions (p<2.0x10-6). Direct investigation between handedness and IDPs revealed numerous associations with functional connectivity between the same language-related areas of the brain. A second GWAS of non-right handers (n=44,631) vs right-handers (n=356,567) revealed an additional locus: rs3094128, 6p21.33, p=2.9x10-8. Three of the four associated loci (2q34, 17q21.31, 6p21.33) contain genes that encode microtubule-related proteins that are highly expressed in the brain: MAP2, MAPT and TUBB. These genes are strongly implicated in the pathogenesis of diseases that are known to affect an excess of left-handed people, including schizophrenia.\n\nConclusionsThis is the first GWAS to identify genome-wide significant loci for human handedness in the general population, and the genes at these loci have biological plausibility in contributing to neurodevelopmental lateralization of brain organisation, which appears to predispose both to left-handedness and to certain neurodegenerative and psychiatric diseases.

neuroscience