Under the leadership of Dr. Dennis A. Turner, the Functional Neurosurgery/Neurophysiology Lab is involved with a wide range of research projects, including:

• Randomized clinical trials in Alzheimer’s disease, Parkinson’s disease, and deep brain stimulation
• Translational research projects including intraoperative research
• Several funded basic science projects regarding Alzheimer’s disease, head injury recovery, stroke, and cerebral metabolism

Collaborations within Duke University include with Anesthesia (Ulrike Hoffmann), Biomedical Engineering (Warren Grill, Jonathan Viventi, Patrick Wolfe), BIAC (John Pearson), Neurology (Carol Colton), and Psychiatry (Shawn Acheson, Scott Moore), and collaborations outside of Duke with Christophe Bernard (Marseille, France), Karim Oweiss (University of Florida) and Tim Denison (Medtronic).

Contact Information

Lab Director

Dennis A. Turner, MD
Professor of Neurosurgery
Professor of Neurobiology

Duke University Medical Center
Box 3807
Durham, North Carolina 27710

Phone: 919-684-6706
Fax: 919-681-8068
E-mail: dennis.turner@duke.edu

Clinical Neuroscience

Dr. Turner has been involved with a number of randomized and prospective clinical trials as a clinical neurosurgeon, including a study surgeon in NASCET trial of carotid endarterectomy, and with a focus on movement disorders in Amgen/Medtronics trial of Parkinson’s disease, Ceregene trials of Parkinson’s disease, NIA/Ceregene Trial of Alzheimer’s disease, randomized trials of DBS for depression (both Medtronics and St. Jude trials) and a number of prospective trials focused on movement disorders and spine disorders.

Representative publications

Bartus RT, Baumann TL, Siffert J, Herzog CD, Alterman R, Boulis N, Turner DA, Stacy M, Lang AE, Lozano AM, Olanow CW (2013) Safety and feasibility of targeting the substantia nigra with AAV2-Neurturin in Parkinsons Disease.  Neurology 80: 1698-1701.

Lang AE, Gill S, Patel NK, Lozano A, et al. Randomized Controlled Trial of Intraputaminal GDNF Infusion in Parkinsons Disease (2006).  Annals Neurology 59: 459-466.

 Olanow CW, Bartus RT, Baumann T et al (Ceregene study group) (2015) Gene delivery of AAV2-neurturin to putamen and substantia nigra in Parkinson’s disease: a double-blind, randomized controlled trial.  Ann Neurology 78: 248-257.

Turner DA (2016) Enhanced Functional Outcome from Traumatic Brain Injury with Brain-Machine Interface Neuromodulation: Neuroprosthetic Scaling in Relation to Injury Severity.  In Laskowitz D, Grant J ed: Translational Research in Traumatic Brain Injury, CRC Press, Frontiers in Neuroscience.

Turner DA (2014) Neurovascular coupling is critical for recovery from spreading depression. Brain 137:2877-2878.

Waldau B, Clayton DA, Gasperson L, Turner DA (2011)  Analysis of the time course of the effects of STN DBS on hand function in Parkinson’s disease. Stereotactic Functional Neurosurgery 89: 48-55.

Funding

NIH 1R01AG030048 [NIA, Ceregene] - Duke PI: J. Burke - 1/1/2010-12/31/2015 - Cere-110 Randomized, Controlled Trial of NGF Gene Therapy in Alzheimer’s Disease

Translational Neuroscience

Dr. Turner has developed a novel intraoperative physiology platform over the past 15 years during DBS procedures in collaboration with several neuroscience and engineering groups. These studies have included analyzing subcortical brain-machine interface approaches with multiunit recording, mechanisms of DBS stimulation efficacy and alternative patterns of stimulation, and DBS electrical recordings for surrogate physiological feedback signals for smart neuroprosthetic devices. These publications demonstrate the capability for intraoperative research as a key step towards understanding mechanisms of DBS, underlying human neurophysiology of movement disorders, and for piloting future applications with implanted brain and nervous system devices.

Representative publications

Brocker DT, Swan BD, So RQ, Turner DA, Gross RE, Grill WM.  Optimized temporal pattern of brain stimulation designed by computational evolution. Science Translational Medicine, in press, 2017. 

Brocker DT, Swan BD, Turner DA, Gross RE, Tatter SB, Koop MM, Bronte-Stewart H, Grill WM (2013)  Improved efficacy of temporally non-regular deep brain stimulation in Parkinsons’s disease.  Experimental Neurology 239: 60-67.

Hanson TL, Fuller AM, Lebedev MA, Turner DA, Nicolelis MA (2012) Subcortical neuronal ensembles: motor task association, tremor, oscillations, and synchrony in human patients. Journal of Neuroscience 32: 8620-863.

Kent AR, Swan BD, Brocker DT, Turner DA, Gross RE, Grill WM (2015) Measurement of evoked potentials during thalamic deep brain stimulation. Brain Stimulation 8:42-56. PMC4277712.

Funding

NIH RO1NS079312 - PI: Warren Grill - 10/1/2012-9/30/2017 - Recording Evoked Potentials for Closed-loop DBS

NIH R21NS084176 - PI: John Pearson - 4/1/2014-3/31/2017 - Mechanisms of Parkinson Impulsivity in Human Subthalamic Nucleus

NIH R37NS040984-11 - PI: Warren Grill - 9/1/2015-8/31/2020 - Temporal Patterns of Deep Brain Stimulation  

NIH R21NS066115 [NINDS] - PI: D.A. Turner - 5/15/2010-4/30/2013 - Realistic Human Perception of Spatio-Temporal Thalamic Microstimulation

Basic Neuroscience

Dr. Turner has extensive experience with the neuroscience of aging, dendritic anatomy, and neurophysiology in hippocampus and hippocampal metabolism in a number of disease conditions, including hypoxia-ischemia, low glucose conditions, and mechanisms of spreading depression. Additionally, he has extensively analyzed the capability of neural grafts (both embryonic and neurosphere-derived) for cell replacement strategies following hippocampal lesions. These publications represent a subset of basic science and translational approaches to understand mechanisms of disease at a cellular neurophysiology level.

Representative publications

Galeffi J, Degan S, Britz GW, Turner DA.  Dysregulation of oxygen hemodynamic responses to synaptic train stimulation in a rat hippocampal model of subarachnoid hemorrhage.  J Cerebral Blood Flow Metabolism 36: 696-701, 2016.  PMC pending.

Galeffi F, Foster KA, Somjen GG, Turner DA (2011) Tissue PO2 and NADH fluorescence during synaptic stimulation and SD reveals dissociation between oxygen utilization and mitochondrial redox state in rat hippocampal slices.  Journal of Cerebral Metabolism Blood Flow 31: 626-639. PMC3049517.

Galeffi F, Shetty PK, Sadgrove MP, Turner DA (2015) Age-related metabolic fatigue during low glucose conditions in rat hippocampus.  Neurobiology of Aging 36: 982-992. PMC4443806.

Ivanov A, Bernard C, Turner DA (2015)  Metabolic responses differentiate between interictal, ictal and persistent epileptiform activity in intact, immature hippocampus in vitro.  Neurobiology Disease 75: 1-14. PMC4351116.

Funding

VA I21 BX003023-01 - PI: D.A. Turner - 4/1/2016-3/31/2018 - Fornix Stimulation Enhances Neurovascular Plasticity in Alzheimer's Mouse Model

VA I21 RX002223 - PI: D.A. Turner - 1/3/2017-12/31/2018 - Delayed Septal/Fornix Brain Stimulation after Repetitive Closed Head Injury

NIH R21 AG051103-01 - PI: D.A. Turner - 9/1/2016-8/31/2018 - Hippocampal Neurovascular Plasticity in CVN-AD Mouse: Fornix-Septal Stimulation

NIH R01 R01AG037599 [NIA] - PI: D.A. Turner - 7/1/2010-6/30/2015 - Neuronal Fatigue in Aging Hippocampus during Sustained Metabolic Demand