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Karlstrom, R. O.

Publications and source records attributed to Karlstrom, R. O..

2 recordsLinked to original sources

Accelerated clearing and molecular labeling of large tissue samples using magnetohydrodynamic force

Here we report a strategy to efficiently render opaque biological tissues transparent and demonstrate that this approach can be modified to rapidly label intact samples with antibodies for large volume fluorescence microscopy. This strategy applies a magnetohydrodynamic (MHD) force to accelerate the removal of lipids from and the introduction of antibodies into tissue samples as large as an intact adult mouse brain. This strategy complements a growing array of tools that enable high-resolution 3-dimensional anatomical analyses in intact tissues using fluorescence microscopy. MHD-accelerated clearing and MHD-accelerated antibody labeling are fast, reliable, inexpensive, and compatible with existing strategies for high-quality fluorescence microscopy of intact tissues.

neuroscience↗

Hedgehog signaling regulates neurogenesis in the larval and adult zebrafish hypothalamus

While neurogenesis in the adult hypothalamus is now known to be essential for proper function, the cell-cell signaling events that regulate neurogenesis in this evolutionarily conserved brain region remain poorly understood. Here we show that Hedgehog (Hh)/Gli signaling positively regulates hypothalamic neurogenesis in both larval and adult zebrafish and is necessary and sufficient for normal hypothalamic proliferation rates. Hedgehog-responsive cells are relatively rapidly proliferating pluripotent neural precursors that give rise to dopaminergic, serotonergic, and GABAergic neurons. in situ and transgenic reporter analyses revealed substantial heterogeneity in cell-cell signaling within the hypothalamic niche, with slow cycling Nestin-expressing cells residing among distinct and overlapping populations of Sonic Hh (Shh)-expressing, Hh-responsive, Notch-responsive, and Wnt-responsive radial glia. This work shows for the first time that Hh/Gli-signaling is a key component of the complex cell-cell signaling environment that regulates hypothalamic neurogenesis throughout life.

neuroscience↗