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Journal of Veterinary Medicine
Volume 2016, Article ID 9561968, 16 pages
http://dx.doi.org/10.1155/2016/9561968
Research Article

Tamoxifen Promotes Axonal Preservation and Gait Locomotion Recovery after Spinal Cord Injury in Cats

1Department of Computer Science, CUCEI, Universidad de Guadalajara, Avenida Revolucion No. 1500 Building M, Laboratory 212, 44430 Guadalajara, JAL, Mexico
2Department of Physiology, CUCS Universidad de Guadalajara, Sierra Mojada 950, Building P Third Floor, 44290 Guadalajara, JAL, Mexico
3Department of Physiology Biophysics and Neurosciences, Centro de Investigacion y Estudios Avanzados IPN, Avenida Instituto Politecnico Nacional 2508, 07360 Mexico City, DF, Mexico
4Department of Veterinary and Medicine, CUCBA Universidad de Guadalajara, Camino Ing. Ramon Padilla Sanchez 2100, 45110 Zapopan, JAL, Mexico
5Department of Neuroscience, CUCS Universidad de Guadalajara, Sierra Mojada 950, Building P Third Floor, 44290 Guadalajara, JAL, Mexico

Received 7 September 2015; Accepted 14 January 2016

Academic Editor: Vito Laudadio

Copyright © 2016 Braniff de la Torre Valdovinos et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We performed experiments in cats with a spinal cord penetrating hemisection at T13-L1 level, with and without tamoxifen treatment. The results showed that the numbers of the ipsilateral and contralateral ventral horn neurons were reduced to less than half in the nontreated animals compared with the treated ones. Also, axons myelin sheet was preserved to almost normal values in treated cats. On the contrary, in the untreated animals, their myelin sheet was reduced to 28% at 30 days after injury (DAI), in both the ipsilateral and contralateral regions of the spinal cord. Additionally, we made hindlimb kinematics experiments to study the effects of tamoxifen on cat locomotion after the injury: at 4, 16, and 30 DAI. We observed that the ipsilateral hindlimb angular displacement (AD) of the pendulum-like movements (PLM) during gait locomotion was recovered to almost normal values in treated cats. Contralateral PLM acquired similar values to those obtained in intact cats. At 4 DAI, untreated animals showed a compensatory increment of PLM occurring in the contralateral hindlimb, which was partially recovered at 30 DAI. Our findings indicate that tamoxifen exerts a neuroprotective effect and preserves or produces myelinated axons, which could benefit the locomotion recovery in injured cats.