Brain Activation and Connectivity in Non-disabled Multiple Sclerosis Patients

iii DEDICATION I dedicate this thesis to my sister Dr. Claudia P. Colorado and my brother Rodrigo J. Colorado who have not stopped caring for me since the day I was born. iv ACKNOWLEDGMENTS This project would not have been possible without the invaluable help of many individuals that I would like to acknowledge. First, I would like to express my greatest gratitude to my supervisory advisor and scientific mentor Dr. Ponnada A. Narayana. His guidance and encouragement throughout every step of the way were essential to make me the scientist that I am today. Every one of our weekly meetings provided direction for my growth and an answer to my questions. I would like to thank the members of my committees for their valuable suggestions and guidance. I am thankful to Dr. Ruth Heidelberger who has advised me and followed my progress since I started my journey in the MD/PhD program. I thank Dr. Khader M. Hasan for his expert guidance on diffusion tensor imaging and his insightful conversations. I am grateful to Dr. Joel L. Steinberg for teaching me the intricacies of functional magnetic resonance imaging and his availability to answer my questions. I am thankful to Dr. Jerry S. Wolinsky for sharing with me his wealth of knowledge about multiple sclerosis, his help recruiting patients and his clinical mentorship. I thank Drs. F. Gerard Moeller and Nehal A. Parikh for participating in my exam committee. I am deeply appreciative to all my fellow lab colleagues who provided me with a nurturing environment to grow as a scientist. I am especially indebted to Drs. Yuxiang Zhou and Karan Shukla for the many experiments we conducted together and their great contributions to this project. I thank my fellow graduate students, past and present, for their support and thoughtful criticism: Dr. I would like to thank the UT-Houston MD/PhD program for providing me the opportunity to become a physician scientist. I especially thank Dr. Dianna Milewicz and Dr. Ruth Heidelberger. I greatly appreciate the emotional encouragement provided by my fellow MD/PhD trainees. I extend especial gratitude to Dr. Without the support from my friends and family, I would not be where I am. I thank my grandparents Mamatita and Papalfonso who provided me the opportunity to attend Colegio Champagnat and gave me the best gift I have ever received. I thank my siblings Claudia, Rodrigo and Mimi for always being …