Selective electrical stimulation of peripheral nerve fibers:accommodation based methods

project was motivated by the idea of using and adapting accommodation-based methods for selective electrical stimulation of motor fibers to the study of the human nociceptive system. This has not been without difficulties, but it has still been a rewarding process, as it has provided the opportunity to study interesting biophysical mechanisms and to enhance the understanding of accommodation based methods. Throughout this project, I am indebted to all the co-workers and friends at the Center of Sensory Motor Interaction and at the Faculty of Dentistry, University of Toronto that I have had the fortune to work with and learn from. I wish to express my sincerest gratitude to my supervisor Associate Prof. Ole K. Andersen and Professor Lars Arendt-Nielsen, the head of Center for Sensory Motor Interaction, for their never failing interest and enthusiasm. I will also like to express my deepest gratitude to my hosts at the Faculty of Dentistry, University of Toronto, Professor Barry J. Sessle and Professor James W. Hu. Furthermore, I will like to thank Dr. Alexandra Vuckovic for graciously offering her volume conducto

Breakdown of accommodation in nerve: a possible role for persistent sodium current

BACKGROUND: Accommodation and breakdown of accommodation are important elements of information processing in nerve fibers, as they determine how nerve fibers react to natural slowly changing stimuli or electrical stimulation. The aim of the present study was to elucidate the biophysical mechanism of breakdown of accommodation, which at present is unknown. RESULTS: A model of a space-clamped motor nerve fiber was developed. It was found that this new model could reproduce breakdown of accommodation when it included a low-threshold, rapidly activating, persistent sodium current. However, the phenomenon was not reproduced when the persistent sodium current did not have fast activation kinetics or a low activation threshold. CONCLUSION: The present modeling study suggests that persistent, low-threshold, rapidly activating sodium currents have a key role in breakdown of accommodation, and that breakdown of accommodation can be used as a tool for studying persistent sodium current under normal and pathological conditions