Stimulation of the right entorhinal white matter enhances visual memory encoding in humans

Emily A Mankin; Zahra M Aghajan; Peter Schuette; Michelle E Tran; Natalia Tchemodanov; Ali Titiz; Güldamla Kalender; Dawn Eliashiv; John Stern; Shennan A Weiss; Dylan Kirsch; Barbara Knowlton; Itzhak Fried; Nanthia Suthana

doi:10.1016/j.brs.2020.11.015

Stimulation of the right entorhinal white matter enhances visual memory encoding in humans

Brain Stimul. 2021 Jan-Feb;14(1):131-140. doi: 10.1016/j.brs.2020.11.015. Epub 2020 Dec 3.

Authors

Affiliations

¹ Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, 300 Stein Plaza, Los Angeles, CA, 90095, USA.
² Department of Psychiatry and Biobehavioral Sciences, Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA, University of California, Los Angeles, 760 Westwood Plaza, Los Angeles, CA, 90095, USA.
³ Department of Psychiatry and Biobehavioral Sciences, Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA, University of California, Los Angeles, 760 Westwood Plaza, Los Angeles, CA, 90095, USA; Department of Bioengineering, University of California, Los Angeles, 410 Westwood Plaza, Los Angeles, CA, 90095, USA.
⁴ Department of Neurology, University of California, Los Angeles, 710 Westwood Plaza, Los Angeles, CA, 90095, USA.
⁵ Department of Psychology, University of California, Los Angeles, 502 Portola Plaza, Los Angeles, CA, 90095, USA.
⁶ Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, 300 Stein Plaza, Los Angeles, CA, 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA, University of California, Los Angeles, 760 Westwood Plaza, Los Angeles, CA, 90095, USA; Functional Neurosurgery Unit, Tel-Aviv Medical Center and Sackler School of Medicine, Tel-Aviv University, P.O.B 39040 Ramat Aviv, Tel-Aviv, 69978, Israel.
⁷ Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, 300 Stein Plaza, Los Angeles, CA, 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA, University of California, Los Angeles, 760 Westwood Plaza, Los Angeles, CA, 90095, USA; Department of Psychology, University of California, Los Angeles, 502 Portola Plaza, Los Angeles, CA, 90095, USA; Department of Bioengineering, University of California, Los Angeles, 410 Westwood Plaza, Los Angeles, CA, 90095, USA. Electronic address: nanthia@ucla.edu.

Abstract

Background: While deep brain stimulation has been successful in treating movement disorders, such as in Parkinson's disease, its potential application in alleviating memory disorders is inconclusive.

Objective/hypothesis: We investigated the role of the location of the stimulating electrode on memory improvement and hypothesized that entorhinal white versus gray matter stimulation would have differential effects on memory.

Methods: Intracranial electrical stimulation was applied to the entorhinal area of twenty-two participants with already implanted electrodes as they completed visual memory tasks.

Results: We found that stimulation of right entorhinal white matter during learning had a beneficial effect on subsequent memory, while stimulation of adjacent gray matter or left-sided stimulation was ineffective. This finding was consistent across three different visually guided memory tasks.

Conclusions: Our results highlight the importance of precise stimulation site on modulation of human hippocampal-dependent memory and suggest that stimulation of afferent input into the right hippocampus may be an especially promising target for enhancement of visual memory.

Keywords: Declarative memory; Deep brain stimulation; Entorhinal cortex; Hippocampus; Intracranial electrical stimulation; White matter.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Entorhinal Cortex
Hippocampus
Humans
Memory
Temporal Lobe
White Matter* / diagnostic imaging

Abstract

Publication types

MeSH terms

Grants and funding