Revealing the long-range three-dimensional organization of tanycyte processes within the basal hypothalamus of mice

REGGIANI P; DE FRANCESCO PN; URIARTE M; PERELLÓ M; CRESPO T; GOYA RG

Congreso; XXXIV Annual Meeting of the Argentinian Society for Neuroscience Research (SAN); 2019

Argentinian Society for Neuroscience Research (SAN)

Hypothalamic tanycytes are specializedependymal cells that line the ventral part of the third ventricle and emitprocesses into the basal hypothalamus. These cells are involved in a host offunctions, including energy homeostasis, nutrient sensing, and hormonaltransport and regulation. Here, we present a novel approach to study theanatomical distribution and fine architecture of the processes of thehypothalamic tanycytes in mice. The ependymal walls were labeled, includingtanycytes and their processes, using an intra-cerebroventricular injection ofan adenoviral vector expressing GFP (RAd-GFP). Then, consecutive brain slices wereobtained using a standard cryotome and sequentially mounted for fluorescencevolume imaging. Tanycyte morphology with fine structural detail was readily labeledand observable in the z-stacks obtained. Continuous volume reconstructions spanningseveral hundreds of microns were achieved using a software tool that wedeveloped for the open source package Fiji. This elastic alignment technique wasable to overcome the deformation introduced by sample slicing, by matching correspondingfeatures in adjacent slices. With this procedure, we were able to map thedistribution and orientation of tanycytic processes throughout the sampledvolume, as well as to identify and map their contacts with the hypothalamic vasculature.This approach provides a valuable tool to study the complex relationship of hypothalamictanycytes and their surrounding parenchyma.