3D Reconstruction of the Clarified Rat Hindbrain Choroid Plexus

• DOI: 10.3389/fcell.2021.692617
• Publication Date: 2021-07-29T17:30:58Z
• Authors: Paola Perin; Riccardo Rossetti; Carolina Ricci; Daniele Cossellu; Simone Lazzarini; Philipp Bethge; Fabian F. Voigt; Fritjof Helmchen; Laura Batti; Ivana Gantar; Roberto Pizzala
• Keywords: Hindbrain; Fourth ventricle; Plexus

The choroid plexus (CP) acts as a regulated gate between blood and cerebrospinal fluid (CSF). Despite its simple histology (a monostratified cuboidal epithelium overlying vascularized stroma), this organ has remarkably complex functions several of which involve local interaction with cells located around ventricle walls. Our knowledge CP structural organization is mainly derived from resin casts, capture the overall features but only allow reconstruction vascular pattern surface, unrelated to loosely related ventricular location. Recently, single cell atlases are starting emerge, providing insight on heterogeneities interactions. So far, however, few studies have described spatial at mesoscale level, because fragile nature deep location within brain. Here, using an iDISCO-based clearing approach light-sheet microscopy, we reconstructed normal rat hindbrain (hCP) macro- microstructure, markers for epithelium, arteries, microvasculature, macrophages, noted association 4th ventricle-related neurovascular structures. hCP organized in domains associated main vessel (fronds) carry variable number villi; latter enclosed by may be flat (leaf-like) or rolled up extent. Arteries feeding emerge cerebellar branch into straight arterioles terminating small capillary anastomotic networks, run villus terminate attaching multiple times large tortuous (LTC) ends vein. Venous outflow mostly follows arterial pathways, except lateral horizontal segment (LHS) caudal sagittal segment. structure fronds villi microvascular surface: when LTCs predominate, leaflike more evident bulge surface; different, corkscrew-like observed reaching close surface spiraling capillaries surrounding them. Both leaf-like reach floor, making contact points their tip, where no gap seen ependyma. Contacts usually adjacent harbor epiplexus macrophages. At junction medial (MHS) segment, supply connected temporal bone subarcuate fossa, venous drains ventral vein exits through cochlear nuclei Luschka foramen. These connections stabilize make MHS-LHS joint particularly very easily damaged removing brain skull. Even samples, (or isolated villi) often remain strongly attached dorsal nucleus (DCN) these fronds, contacts still present connecting “bridges” seen, suggesting presence real molecular rather than mere appositions.