Direct Electrical Stimulation of the Human Entorhinal Region and Hippocampus Impairs Memory

Joshua Jacobs; Jonathan Miller; Sang Ah Lee; Tom Coffey; Andrew J Watrous; Michael R Sperling; Ashwini Sharan; Gregory Worrell; Brent Berry; Bradley Lega; Barbara C Jobst; Kathryn Davis; Robert E Gross; Sameer A Sheth; Youssef Ezzyat; Sandhitsu R Das; Joel Stein; Richard Gorniak; Michael J Kahana; Daniel S Rizzuto

doi:10.1016/j.neuron.2016.10.062

Direct Electrical Stimulation of the Human Entorhinal Region and Hippocampus Impairs Memory

Neuron. 2016 Dec 7;92(5):983-990. doi: 10.1016/j.neuron.2016.10.062.

Authors

Joshua Jacobs¹, Jonathan Miller², Sang Ah Lee³, Tom Coffey⁴, Andrew J Watrous², Michael R Sperling⁵, Ashwini Sharan⁵, Gregory Worrell⁶, Brent Berry⁶, Bradley Lega⁷, Barbara C Jobst⁸, Kathryn Davis⁹, Robert E Gross¹⁰, Sameer A Sheth¹¹, Youssef Ezzyat¹², Sandhitsu R Das⁹, Joel Stein⁹, Richard Gorniak⁵, Michael J Kahana¹², Daniel S Rizzuto¹²

Affiliations

¹ Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA. Electronic address: joshua.jacobs@columbia.edu.
² Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
³ Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA; Center for Mind/Brain Sciences, University of Trento, 38068 Rovereto, Italy.
⁴ Department of Biomedical Engineering, Drexel University, Philadephia, PA 19104, USA.
⁵ Thomas Jefferson University, Philadelphia, PA 19107, USA.
⁶ Mayo Clinic, Rochester, MN 55905, USA.
⁷ University of Texas, Southwestern, Dallas, TX 75390, USA.
⁸ Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
⁹ Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA.
¹⁰ Department of Neurosurgery, Emory University, Atlanta, GA 30322, USA.
¹¹ Department of Neurosurgery, Columbia University Medical Center, New York, NY 10032, USA.
¹² Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA.

PMID: 27930911
DOI: 10.1016/j.neuron.2016.10.062

Abstract

Deep brain stimulation (DBS) has shown promise for treating a range of brain disorders and neurological conditions. One recent study showed that DBS in the entorhinal region improved the accuracy of human spatial memory. Based on this line of work, we performed a series of experiments to more fully characterize the effects of DBS in the medial temporal lobe on human memory. Neurosurgical patients with implanted electrodes performed spatial and verbal-episodic memory tasks. During the encoding periods of both tasks, subjects received electrical stimulation at 50 Hz. In contrast to earlier work, electrical stimulation impaired memory performance significantly in both spatial and verbal tasks. Stimulation in both the entorhinal region and hippocampus caused decreased memory performance. These findings indicate that the entorhinal region and hippocampus are causally involved in human memory and suggest that refined methods are needed to use DBS in these regions to improve memory.

Keywords: deep brain stimulation; entorhinal cortex; hippocampus; memory; navigation; theta oscillation.

Publication types

Video-Audio Media

MeSH terms

Deep Brain Stimulation*
Entorhinal Cortex / physiology*
Epilepsy
Hippocampus / physiology*
Humans
Memory / physiology
Spatial Memory / physiology*
Task Performance and Analysis