Biology subjects

Schoenrock, S.

Publications and source records attributed to Schoenrock, S..

3 recordsLinked to original sources

bioRxiv2024

Interhemispheric Connectivity of the Human Temporal Lobes

Much is known regarding the major white matter pathways connecting the right and left temporal lobes, which project through the posterior corpus callosum, the anterior commissure, and the dorsal hippocampal commissure. However, details about the spatial location of these tracts are unclear, including their exact course and proximity to cortical and subcortical structures, the spatial relations between corpus callosum and anterior commissure projections, and the caudal extent of transcallosal connections within the splenium. We present an atlas of these tracts derived from high angular resolution diffusion tractography maps, providing improved visualization of the spatial relationships of these tracts. The data show several new details, including branching of the transcallosal pathway into medial and lateral divisions, projections of the transcallosal pathway into the external capsule and claustrum, complex patterns of overlap and interdigitation of the transcallosal and anterior commissure tracts, distinct dorsal and ventral regions of the splenium with high tract densities, and absence of temporal lobe projections in the caudal third of the splenium. Intersection of individual tract probability maps with individual cortical surfaces were used to identify likely regions with relatively higher cortical termination densities. These data should be useful for planning surgical approaches involving the temporal lobe and for developing functional-anatomical models of processes that depend on interhemispheric temporal lobe integration, including speech perception, semantic memory, and social cognition. HighlightsO_LIInterhemispheric connections of the human temporal lobes were visualized using high angular resolution diffusion tensor imaging tractography. C_LIO_LIResults are displayed on serial orthogonal sections to reveal detailed spatial relationships. C_LIO_LICorpus callosum projections through the splenium form distinct dorsal and ventral bundles and are absent from the caudal splenium. C_LIO_LIThe transcallosal pathway consists of distinct medial and lateral divisions. C_LIO_LIThe results reveal projections to the external capsule and claustrum not previously described. C_LIO_LITranscallosal and anterior commissural pathways show complex patterns of overlap and interdigitation. C_LIO_LISurface mapping revealed areas with relatively high density of projections to the cortical surface. C_LI

neuroscience↗

bioRxiv2022

The Collaborative Cross strains and their founders vary widely in cocaine-induced behavioral sensitization

Cocaine use and overdose deaths attributed to cocaine have increased significantly in the United States in the last 10 years. Despite the prevalence of cocaine use disorder (CUD) and the personal and societal problems it presents, there are currently no approved pharmaceutical treatments. The absence of treatment options is due, in part, to our lack of knowledge about the etiology of CUDs. There is ample evidence that genetics plays a role in increasing CUD risk but thus far, very few risk genes have been identified in human studies. Genetic studies in mice have been extremely useful for identifying genetic loci and genes, but have been limited to very few genetic backgrounds, leaving substantial phenotypic and genetic diversity unexplored. Herein we report the measurement of cocaine-induced behavioral sensitization using a 19-day protocol that captures baseline locomotor activity, acute locomotor response to cocaine and locomotor sensitization across 5 exposures to the drug. These behaviors were measured in 51 genetically diverse yet tractable Collaborative Cross (CC) strains along with their inbred founder strains. The CC was generated by crossing 8 genetically diverse inbred strains such that each inbred CC strain has genetic contributions from each of the founder strains. Inbred CC mice are infinitely reproducible and provide a stable, yet diverse genetic platform on which to study the genetic architecture and genetic correlations among phenotypes. We have identified significant differences in cocaine locomotor sensitivity and behavioral sensitization across the panel of CC strains and their founders. We have established relationships among cocaine sensitization behaviors and identified extreme responding strains that can be used in future studies aimed at understanding the genetic, biological and pharmacological mechanisms that drive addiction-related behaviors. Finally, we have determined that these behaviors exhibit relatively robust heritability making them amenable to future genetic mapping studies to identify addiction risk genes and genetic pathways that can be studied as potential targets for the development of novel therapeutics.

genetics↗

bioRxiv2018

Reciprocal F1 hybrids of two inbred mouse strains reveal parent-of-origin and perinatal diet effects on behavior and expression

Parent-of-origin effects (POEs) in mammals typically arise from maternal effects or from imprinting. Mutations in imprinted genes have been associated with psychiatric disorders, as well as with changes in a handful of animal behaviors. Nonetheless, POEs on complex traits such as behavior remain largely uncharacterized. Furthermore, although perinatal environmental exposures, such as nutrient deficiency, are known to modify both behavior and epigenetic effects generally, the architecture of environment-by-POE is almost completely unexplored. To study POE and environment-by-POE, we employ a relatively neglected but maximally powerful POE-detection system: a reciprocal F1 hybrid population. We exposed female NOD/ShiLtJxC57Bl/6J and C57Bl/6JxNOD/ShiLtJ mice, in utero, to one of four different diets, then after weaning recorded their whole-brain gene expression, as well as a set of behaviors that model psychiatric disease. Microarray expression data revealed an imprinting-enriched set of over a dozen genes subject to POE; the POE on the most significantly affected gene, Carmil1 (a.k.a. Lrrc16a), was validated using qPCR in the same and in a new set of mice. Several behaviors, especially locomotor behaviors, also showed POE. Interestingly, Bayesian mediation analysis suggests Carmil1 expression suppresses behavioral POE, and Airn suppresses POE on Carmil1 expression. A significant diet-by-POE was observed on one behavior, one imprinted gene, and over a dozen non-imprinted genes. Beyond our particular results, our study demonstrates a reciprocal F1 hybrid framework for studying POE and environment-by-POE on behavior.

genetics↗