Modulation of hippocampal activity with fornix Deep Brain Stimulation.

Autor: Stypulkowski PH; Medtronic, Minneapolis, MN, USA. Electronic address: paul.stypulkowski@medtronic.com., Stanslaski SR; Medtronic, Minneapolis, MN, USA., Giftakis JE; Medtronic, Minneapolis, MN, USA.
Jazyk: angličtina
Zdroj: Brain stimulation [Brain Stimul] 2017 Nov - Dec; Vol. 10 (6), pp. 1125-1132. Date of Electronic Publication: 2017 Sep 06.
DOI: 10.1016/j.brs.2017.09.002
Abstrakt: Background: Deep Brain Stimulation (DBS) within the Papez circuit is under investigation as a treatment for epilepsy and Alzheimer's disease. We previously reported the effects of stimulation at nodes within this network (anterior thalamic nucleus and hippocampus) on hippocampal activity in a large animal model, using a chronic implantable, clinical-grade system that permits concurrent stimulation and recording.
Objective: In this study we extended earlier work to compare the effects of fornix DBS on evoked potentials (EPs) and local field potential (LFP) activity within the hippocampus, and to assess closed-loop stimulation.
Methods: Unilateral fornix and hippocampal DBS leads were implanted in three ovine subjects using image-guided, frameless stereotaxy. Chronic, awake recordings of EPs and LFPs in response to fornix and hippocampal stimulation were collected with the implanted device and analyzed off-line.
Results: Stimulation of the fornix produced robust, short latency hippocampal EPs. High frequency fornix stimulation generated parameter-dependent effects. At low amplitudes, short lasting inhibition of LFP activity occurred. Above a specific amplitude threshold, DBS elicited pronounced bursts of theta activity, followed by a marked state shift in hippocampal activity. These effects persisted for minutes post-DBS and were reflected as changes in LFP spectral content and phase-amplitude coupling. Real-time modulation of hippocampal activity via the implanted device was demonstrated using LFPs as the control signal for closed-loop stimulation.
Conclusions: The current results expand earlier findings and demonstrate target-specific effects produced by DBS within this neural circuit. These changes in network activity may provide insights into stimulation targets and parameter selection for clinical investigations.
(Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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