DOI: 10.25378/janelia.23969106.v1
title: Isotropic 3D electron microscopy (FIB-SEM) data of mouse double-innervated Meissner corpuscle (jrc_mus-meissner-corpuscle-2)

description: <b>Sample:</b> Double-innervated Meissner corpuscle from the forepaw of a 3-week-old C57BL/6J WT mouse<b>Sample Description:</b> Across mammalian skin, structurally complex and diverse mechanosensory end organs respond to mechanical stimuli and enable our perception of dynamic, light touch. How forces act on morphologically dissimilar mechanosensory end organs of the skin to gate the requisite mechanotransduction channel Piezo2 and excite mechanosensory neurons is not understood. Here, we report high-resolution reconstructions of the hair follicle lanceolate complex, Meissner corpuscle, and Pacinian corpuscle and the subcellular distribution of Piezo2 within them. Across all three end organs, Piezo2 is restricted to the sensory axon membrane, including axon protrusions that extend from the axon body. These protrusions, which are numerous and elaborate extensively within the end organs, tether the axon to resident non-neuronal cells via adherens junctions. These findings support a unified model for dynamic touch in which mechanical stimuli stretch hundreds to thousands of axon protrusions across an end organ, opening proximal, axonal Piezo2 channels and exciting the neuron.This dataset contains the FIB-SEM data of a double-innervated Meissner corpuscle from the forepaw of a 3-week-old C57BL/6J mouse.<b>Protocol:</b> Samples were dissected and drop fixed in glutaraldehyde and paraformaldehyde, and then osmicated with osmium tetroxide and potassium ferrocyanide, followed by osmium tetroxide only. Samples were subsequently stained with uranyl acetate and samarium chloride. Samples were dehydrated with an ethanol series followed by anhydrous acetone, infiltrated with Durcupan resin, and cured at 60°C.<b>Contributions:</b> Sample provided by Annie Handler (Harvard Medical School/HHMI) and Qiyu Zhang (Harvard Medical School/HHMI), prepared for imaging by Song Pang (HHMI/Janelia, currently at Yale School of Medicine), imaged by Song Pang and C. Shan Xu (HHMI/Janelia, currently at Yale School of Medicine), post data registration by C. Shan Xu, global image alignment and processing by Annie Handler and Qiyu Zhang, automatic segmentation by Tri M. Nguyen (Harvard Medical School) under the supervision of Wei-Chung Allen Lee (Harvard Medical School), ground truth annotation by Rebecca Plumb, Brianna Sanchez, Karyl Ashjian, Aria Shotland, Bartianna Brown, Madiha Kabeer, Nusrat Africawala, Stuart Cattel, Annie Handler, and Qiyu Zhang (all Harvard Medical School/HHMI), and segmentation proofreading by Annie Handler, Qiyu Zhang, and Michael Nolan-Tamariz (Harvard Medical School/HHMI).<b>Acquisition ID:</b> jrc_mus-meissner-corpuscle-2<b>Voxel size (nm):</b> 6 x 6 x 6 (x, y, z)<b>Data dimensions (µm): </b>74.1 x 55.1 x 69.6 (x, y, z)<b>Scanning speed (MHz): </b>1<b>Dataset URL:</b> s3://janelia-cosem-datasets/jrc_mus-meissner-corpuscle-2/jrc_mus-meissner-corpuscle-2<b>Visualization Website</b>: https://openorganelle.janelia.org/datasets/jrc_mus-meissner-corpuscle-2<b>Publication: </b>Handler et al., 2023<br><br>