{"335801":{"#nid":"335801","#data":{"type":"event","title":"Georgia Tech Neural Engineering and Young Innovators in Biomedical Engineering Seminar","body":[{"value":"\u003Cp class=\u0022title\u0022\u003E\u003Cstrong\u003ESpeaker: \u003C\/strong\u003ESridevi V. Sarma, PhD\u003Cstrong\u003E\u003Cbr \/\u003E \u003Cstrong\u003EAffiliation: \u003C\/strong\u003E\u003C\/strong\u003EAssistant Professor, Johns Hopkins University Department of Biomedical Engineering and Institute for Computational Medicine\u003Cstrong\u003E\u003Cbr \/\u003E\u003C\/strong\u003E\u003C\/p\u003E\u003Cp class=\u0022title\u0022\u003E\u003Cstrong\u003ETopic:\u003C\/strong\u003E \u0022On the Therapeutic Mechanisms of Deep Brain Stimulation for Parkinson\u0027s Disease: Why High Frequency?\u0022\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EVideo Conference:\u003C\/strong\u003E HSRB E160 \u0026amp; TEP 208\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ENeural Engineering Center Reception to follow\u0026nbsp;in the BME Atrium\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ESeminar Abstract\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDeep brain stimulation (DBS) is clinically recognized to\u0026nbsp;treat movement disorders in Parkinson\u0027s disease (PD), but its\u0026nbsp;therapeutic mechanisms remain elusive. One thing is clear though: high\u0026nbsp;frequency periodic DBS (130-180Hz) is therapeutic, while low frequency\u0026nbsp;DBS is not therapeutic and may even worsen symptoms. So, what is so\u0026nbsp;special about high frequency? In this talk, we address this question\u0026nbsp;by discussing our viewpoint supported by recent results from our key\u0026nbsp;studies of the thalamo-cortical-basal ganglia motor loop. First, thalamic cells play a pivotal role in performing movements by\u0026nbsp;selectively relaying motor-related information back to cortex under\u0026nbsp;the control of modulatory signals from the basal ganglia (BG). Through\u0026nbsp;computational models of the thalamic cells, bifurcation analysis, and\u0026nbsp;single unit recordings from healthy primates and PD patients engaged\u0026nbsp;in motor tasks, we show that (i) there is a set of BG signals (\u0022Proper\u0026nbsp;Relay Set\u0022, PRS), under which the thalamic cells can reliably relay\u0026nbsp;the motor commands, and that (ii) the BG signals belong to the PRS in\u0026nbsp;healthy conditions but are outside the PRS under PD conditions. Then, we use a detailed computational model of the motor loop under PD\u0026nbsp;conditions to study the effects of DBS on the BG signals projecting to\u0026nbsp;the thalamic cells. We show that high frequency periodic DBS steers\u0026nbsp;the BG signals back to the PRS while lower frequency regular DBS and\u0026nbsp;irregular DBS do not. Furthermore, through numerical simulation of the\u0026nbsp;model we show that DBS pulses evoke inputs that propagate through the\u0026nbsp;motor loop both orthodromically (i.e., forward) and antidromically\u0026nbsp;(i.e., backward) and fade away within a few milliseconds, thus having\u0026nbsp;little effects on the BG signals. However, when the latency between\u0026nbsp;consecutive DBS pulses is small (i.e., DBS is high frequency) and\u0026nbsp;constant over time (i.e., DBS is periodic), then orthodromic and\u0026nbsp;antidromic effects can overlap within the loop and result into a\u0026nbsp;strong, long-lasting perturbation that ultimately drives the BG signals.\u0026nbsp;Taken together, these results provide a holistic, albeit abstract,\u0026nbsp;view of motor control in healthy and PD conditions, account for the\u0026nbsp;neural mechanisms of therapeutic DBS, and suggest that the merit of\u0026nbsp;DBS likely depend on the closed-loop nature of the\u0026nbsp;thalamo-cortical-basal ganglia system.\u003C\/p\u003E\u003Cp\u003EFaculty Host is Christopher J. Rozell, Ph.D.\u003C\/p\u003E\u003Cp\u003EFaculty Co-Host is Garrett B. Stanley, Ph.D.\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003ESridevi Sarma, an assistant professor in the Department of Biomedical Engineering at Johns Hopkins University, will deliver a seminar for the Georgia Tech Neural Engineering Center and Young Innovators in Biomedical Engineering on October 28.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Sridevi Sarma, an assistant professor in the Department of Biomedical Engineering at Johns Hopkins University, will deliver a seminar for the Georgia Tech Neural Engineering Center and Young Innovators in Biomedical Engineering on October 28."}],"uid":"27241","created_gmt":"2014-10-21 08:26:25","changed_gmt":"2017-04-13 21:21:23","author":"Jackie Nemeth","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2014-10-28T12:00:00-04:00","event_time_end":"2014-10-28T13:00:00-04:00","event_time_end_last":"2014-10-28T13:00:00-04:00","gmt_time_start":"2014-10-28 16:00:00","gmt_time_end":"2014-10-28 17:00:00","gmt_time_end_last":"2014-10-28 17:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"1255","name":"School of Electrical and Computer Engineering"}],"categories":[],"keywords":[{"id":"249","name":"Biomedical Engineering"},{"id":"167982","name":"Sridevi V. Sarma"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1795","name":"Seminar\/Lecture\/Colloquium"}],"invited_audience":[{"id":"78751","name":"Undergraduate students"},{"id":"78761","name":"Faculty\/Staff"},{"id":"174045","name":"Graduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EChris Rozell\u003C\/p\u003E\u003Cp\u003ESchool of Electrical and Computer Engineering\u003C\/p\u003E\u003Cp\u003E404-385-7671\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022mailto:crozell@gatech.edu\u0022\u003Ecrozell@gatech.edu\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}