PT  - JOURNAL ARTICLE
AU  - Cynthia Soderblom
AU  - Do-Hun Lee
AU  - Abdul Dawood
AU  - Melissa Carballosa
AU  - Andrea Jimena Santamaria
AU  - Francisco D. Benavides
AU  - Stanislava Jergova
AU  - Robert M. Grumbles
AU  - Christine K. Thomas
AU  - Kevin K. Park
AU  - James David Guest
AU  - Vance P. Lemmon
AU  - Jae K. Lee
AU  - Pantelis Tsoulfas
TI  - 3D Imaging of Axons in Transparent Spinal Cords from Rodents and Nonhuman Primates
AID  - 10.1523/ENEURO.0001-15.2015
DP  - 2015 Mar 01
TA  - eneuro
PG  - ENEURO.0001-15.2015
VI  - 2
IP  - 2
4099  - http://www.eneuro.org/content/2/2/ENEURO.0001-15.2015.short
4100  - http://www.eneuro.org/content/2/2/ENEURO.0001-15.2015.full
SO  - eneuro2015 Mar 01; 2
AB  - The histological assessment of spinal cord tissue in three dimensions has previously been very time consuming and prone to errors of interpretation. Advances in tissue clearing have significantly improved visualization of fluorescently labelled axons. While recent proof-of-concept studies have been performed with transgenic mice in which axons were prelabeled with GFP, investigating axonal regeneration requires stringent axonal tracing methods as well as the use of animal models in which transgenic axonal labeling is not available. Using rodent models of spinal cord injury, we labeled axon tracts of interest using both adeno-associated virus and chemical tracers and performed tetrahydrofuran-based tissue clearing to image multiple axon types in spinal cords using light sheet and confocal microscopy. Using this approach, we investigated the relationships between axons and scar-forming cells at the injury site as well as connections between sensory axons and motor pools in the spinal cord. In addition, we used these methods to trace axons in nonhuman primates. This reproducible and adaptable virus-based approach can be combined with transgenic mice or with chemical-based tract-tracing methods, providing scientists with flexibility in obtaining axonal trajectory information from transparent tissue.