Our research group focuses on developing and translating neuromodulation technologies for the treatment of neurological disorders. We focus on understanding how the brain responds and adapts to stimulation-based therapies from a combination of experimental and computational perspectives. These studies provide us with a rationale to in turn develop, evaluate, and translate new approaches for improving patient care.
(1) Neurophysiology: Our group investigates the therapeutic mechanisms of neuromodulation experimentally through multi-channel electrophysiological and neurochemical techniques in animal models of movement disorders. We are particularly interested in how neurons encoding movement are modulated during deep brain stimulation, how stimulation at different therapeutic efficacies influences these neurons, and how the modulation of neuronal firing patterns changes during chronic stimulation.
(2) Computational Modeling: Our group also develops multi-scale computational neuron models to further our understanding of the biophysical and physiological mechanisms of neuromodulation. In partnership with the Minnesota Supercomputing Institute, we run large-scale simulations that predict how deep brain stimulation affects neural pathways adjacent to and downstream of the stimulated electrodes. We have several projects that use these models retrospectively (e.g. relating clinical outcome to targeted pathway) and prospectively (e.g. predicting how stimulation through a new electrode design would impact activity in the brain).
(3) Translational Studies: The third arm of our research laboratory involves developing new types of neuromodulation strategies, for treating movement disorders, that are inspired by the underlying neuroscience of therapeutic deep brain stimulation. Our group evaluates these technologies experimentally with the goal of leveraging our industrial partnerships to then translate these therapies from the laboratory to the clinic.
(For a comprehensive list of recent publications, refer to PubMed, a service provided by the National Library of Medicine.)
- Xiao Y, Agnesi F, Bello EM, Zhang S, Vitek JL, Johnson MD. Deep brain stimulation induces sparse distributions of locally modulated neuronal activity. Sci Rep. 2018 Feb 1;8(1):2062.
- Ramirez-Zamora A, Giordano JJ, Gunduz A, Brown P, Sanchez JC, Foote KD, Almeida L, Starr PA, Bronte-Stewart HM, Hu W, McIntyre C, Goodman W, Kumsa D, Grill WM, Walker HC, Johnson MD, Vitek JL, Greene D, Rizzuto DS, Song D, Berger TW, Hampson RE, Deadwyler SA, Hochberg LR, Schiff ND, Stypulkowski P, Worrell G, Tiruvadi V, Mayberg HS, Jimenez-Shahed J, Nanda P, Sheth SA, Gross RE, Lempka SF, Li L, Deeb W, Okun MS. Evolving Applications, Technological Challenges and Future Opportunities in Neuromodulation: Proceedings of the Fifth Annual Deep Brain Stimulation Think Tank. Front Neurosci. 2017;11:734.
- Escobar Sanabria D, Johnson LA, Nebeck SD, Zhang J, Johnson MD, Baker KB, Molnar GF, Vitek JL. Parkinsonism and vigilance: alteration in neural oscillatory activity and phase-amplitude coupling in the basal ganglia and motor cortex. J Neurophysiol. 2017;118:2654-2669.
- Moore KM, Himmler BT, Teplitzky BA, Johnson MD, Meisel RL. Measuring in vivo changes in extracellular neurotransmitters during naturally rewarding behaviors in female Syrian hamsters. J Vis Exp. 2017 Sep 12;(127). doi: 10.3791/56135.
- Wang J, Johnson LA, Jensen AL, Baker KB, Molnar GF, Johnson MD, Vitek JL. Network-wide oscillations in the parkinsonian state: alterations in neuronal activities occur in the premotor cortex in parkinsonian nonhuman primates. J Neurophysiol. 2017;117:2242-2249.
- Peña E, Zhang S, Deyo S, Xiao Y, Johnson MD. Particle swarm optimization for programming deep brain stimulation arrays. J Neural Eng. 2017;14(1):016014.
- Connolly AT, Vetter RJ, Hetke JF, Kipke DR, Pellinen DS, Anderson DJ, Baker KB, Vitek JL, Johnson MD. A novel lead design for modulation and sensing of deep brain structures." IEEE Trans Biomed Eng. 2016;63:148-157.
- Neren D, Johnson MD, Legon W, Ling G, Divani AA. Vagus nerve stimulation and other neuromodulation methods for treatment of traumatic brain injury. Neurocrit Care. 2016;24:308-19.
- Connolly AT, Muralidharan A, Hendrix C, Gupta R, Stanslaski S, Denison T, Baker KB, Vitek JL, Johnson MD. Local field potential recordings in a non-human primate model of Parkinson's disease using the Activa® PC+S. J Neural Eng. 2015 Dec;12(6):066012.
- Xiao Y, Johnson MD. Spherical statistics for characterizing the spatial distribution of deep brain stimulation effects on neuronal activity. J Neurosci Methods. 2015;255:52-65.
- Agnesi F, Muralidharan A, Baker KB, Vitek JL, Johnson MD. Fidelity of frequency and phase entrainment of circuit-level spike activity during DBS. J Neurophysiol. 2015;114(2):825-834.
- Connolly AT, Jensen AL, Baker KB, Vitek JL, Johnson MD. Classification of pallidal oscillations with increasing parkinsonian severity. J Neurophysiol. 2015;114:209-218.
- Zitella LM, Teplitzky BA, Yager P, Hudson HM, Brintz K, Duchin Y, Harel N, Vitek JL, Baker KB, Johnson MD. Subject-specific computational modeling of DBS in the PPTg area. Front Comput Neurosci. 2015 Jul 14;9:93.
- Zitella LM, Xiao Y, Teplitzky BA, Kastl DJ, Duchin Y, Baker KB, Vitek JL, Adriany G, Yacoub E, Harel N, Johnson MD. In Vivo 7T MRI of the Non-Human Primate Brainstem. PLoS One. 2015 May 12;10(5):e0127049.
- Connolly AT, Jensen AL, Bello EM, Netoff TI, Baker KB, Johnson MD, Vitek JL. Modulations in oscillatory frequency and coupling in globus pallidus with increasing parkinsonian severity. J Neurosci. 2015;35:6231-6240
- Teplitzky BA, Connolly AT, Bajwa JA, Johnson MD. Computational modeling of an endovascular approach to deep brain stimulation. J Neural Eng. 2014 Apr;11(2):026011.
- Chu LL, Xu Y, Yang JR, Hu YA, Chang HH, Lai HY, Tseng CC, Wang HY, Johnson MD, Wang JK, Lin CY. Human cancer cells retain modest levels of enzymatically active matriptase only in extracellular milieu following induction of zymogen activation. PLoS One. 2014 Mar 24;9(3):e92244.
- Agnesi F, Connolly AT, Baker KB, Vitek JL, Johnson MD. Deep brain stimulation imposes complex informational lesions. PLoS One. 2013 Aug 26;8(8):e74462.
- Zitella LM, Mohsenian K, Pahwa M, Gloeckner C, Johnson MD. Computational modeling of pedunculopontine nucleus deep brain stimulation. J Neural Eng. 2013 Aug;10(4):045005.
- Johnson MD, Lim HH, Netoff TI, Connolly AT, Johnson N, Roy A, Holt A, Lim KO, Carey JR, Vitek JL, He B. Neuromodulation for brain disorders: challenges and opportunities. IEEE Trans Biomed Eng. 2013;60:610-24.
- Agnesi F, Johnson MD, Vitek JL. Deep brain stimulation: how does it work? Handb Clin Neurol. 2013;116:39-54.
- Keane M, Deyo S, Abosch A, Bajwa JA, Johnson MD. Improved spatial targeting with directionally segmented deep brain stimulation leads for treating essential tremor. J Neural Eng. 2012;9:046005.
- Johnson MD, Zhang J, Ghosh D, McIntyre CC, Vitek JL. Neural targets for relieving parkinsonian rigidity and bradykinesia with pallidal deep brain stimulation. J Neurophysiol. 2012;108:567-577.
- Connolly AT, Bajwa JA, Johnson MD. Cortical magnetoencephalography of deep brain stimulation for the treatment of postural tremor. Brain Stimul. 2012;5:616-624.
Current Graduate Students:
Alex Doyle (Neuroscience, University of Minnesota).