Steve K. Esser

 

 

E-mail: skesser@wisc.edu

Research Project:

Transcranial magnetic stimulation (TMS) is a recently developed technique that permits noninvasive brain stimulation in human subjects. Depending on the stimulation parameters used, TMS can disrupt or induce activity in a particular cortical region, thereby providing a valuable tool for the study of motor and sensory processes, attention, memory and language. Moreover, the delivery of trains of TMS pulses, called repetitive TMS (rTMS), is being actively investigated for its ability to induce long-term synaptic changes that may have therapeutic uses. Indeed, in a number of clinical studies, rTMS has been used with varying levels of success to treat disorders such as depression, epilepsy and Parkinson’s disease.

While TMS is clearly a useful experimental tool with emerging clinical relevance, magnetic interference produced by the TMS pulse and constraints arising from the involvement of human subjects have limited TMS research to primarily measuring motor and behavioral responses. New approaches are needed if a detailed investigation of brain activity induced by TMS is to be achieved. In my research, I use computer modeling and high-density electroencephalography to gain a better understanding of how TMS affects neural circuits, and thereby how it can be usefully employed for diagnostic and therapeutic purposes.

Abstracts and publications:

• Massimini, M., F. Ferrarelli, S.K. Esser, B.A. Riedner, R. Huber, M. Murphy, M.J. Peterson, and G. Tononi. 2007. Triggering Sleep slow waves by transcranial magnetic stimulation. PNAS. In Press.
• Huber, R., S.K. Esser, F. Ferrarelli, M. Massimini, M.J. Peterson, and G. Tononi. 2007. TMS-induced cortical potentiation during wakefulness locally increases slow wave activity during sleep. PLOS-ONE 2: e276 [PDF]
• Esser, S.K., R. Huber, M. Massimini, M.J. Peterson, F. Ferrarelli, and G. Tononi. 2006. A direct demonstration of cortical LTP in humans: a combined TMS/EEG study. Brain Res. Bull. 69: 86-94
• Ferrarelli, F., R. Huber, M.J. Peterson, M. Massimini, S.K. Esser, and G. Tononi. 2006. Sleep EEG abnormalities in subjects with schizophrenia. APSS Abstr.
• Esser, S.K., S.L. Hill, and G. Tononi. 2006. Large-scale modeling of the cortical response to transcranial magnetic stimulation during wakefulness and sleep. APSS Abstr.
• Huber, R., S.K. Esser, M. Massimini, F. Ferrarelli, M.J. Peterson, and G. Tononi. 2006. Repetitive transcranial magnetic stimulation during wakefulness induces a local increase in EEG slow wave activity during subsequent sleep. APSS Abstr.
• Huber, R., M.F. Ghilardi, S.K. Esser, M. Massimini, F. Ferrarelli, B.A. Riedner, M.J. Peterson, and G. Tononi. 2006. Slow-wave activity as an electrophysiological marker of synaptic plasticity: Human high density EEG recordings. ESRS Congress, Innsbruck.
• Massimini, M., F. Ferrarelli, R. Huber, M. Murphy, M. Peterson, B. Riedner, S.K.Esser, and G. Tononi. 2006. EEG responses to magnetic cortical stimulation during REM sleep. APSS Abstr.
• Esser, S.K., S.L. Hill, and G. Tononi. 2005. Modeling the effects of transcranial magnetic stimulation on cortical circuits. J. Neurophysiol. 94: 622-639. [PDF]
• Massimini, M., F. Ferrarelli, R. Huber, S.K. Esser, H. Singh, G. Tononi. 2005. Breakdown of cortical effective connectivity during sleep. Science 309: 2228-2232.
• Esser, S.K., R. Huber, M. Massimini, F. Ferrarelli, M.J. Peterson, and G. Tononi. 2005. rTMS induces potentiation of cortical responses. Soc. Neurosci. Abst.
• Ferrarelli, F., M.J. Peterson, R. Huber, M. Massimini, S.K. Esser, and G. Tononi. 2005. Sleep spindle abnormalities in schizophrenia. Soc. Neurosci. Abstr.
• Huber, R., S.K. Esser, M. Massimini, F. Ferrarelli, M.J. Peterson, and G. Tononi. 2005. rTMS during wakefulness induces a local increase in EEG slow wave activity during subsequent sleep. Soc. Neurosci. Abstr.
• Massimini, M., S.K. Esser, F. Ferrarelli, R. Huber, M. Peterson, H. Singh, and G. Tononi. 2005. Excitability and effective connectivity of the human cerebral cortex across the sleep-wake cycle: A TMS/EEG study. APSS Abstr.
• Massimini, M., F. Ferrarelli, M.J. Peterson, S.K. Esser, R. Huber, M. Lazar, A. Alexander, and G. Tononi. 2005. Cortical EEG response to TMS in schizophrenia patients and normal controls. Soc. Neurosci. Abstr.
• Massimini, M., S.K. Esser, F. Ferrarelli, S. Hill, R. Huber, M. Peterson, and G. Tononi. 2004. Effective connectivity of the human cerebral cortex in sleep and wakefulness: A TMS/EEG study. Soc. Neurosci. Abstr.
• Hill, S.L., M. Missimini, S.K. Esser, and G. Tononi. 2003. Simulating cortical TMS during sleep and wakefulness. APSS Abstr.