Memory encoding-related anterior hippocampal potentials are modulated by deep brain stimulation of the entorhinal area

作者：Hansen Niels^*; Chaieb Leila; Derner Marlene; Hampel Kevin G.; Elger Christian E.; Surges Rainer; Staresina Bernhard; Axmacher Nikolai; Fell Juergen

来源：Hippocampus, 2018, 28(1): 12-17.

DOI：10.1002/hipo.22808

• anterior hippocampus
• associative memory
• deep brain stimulation
• entorhinal area
• event-related potentials

Background: Deep brain stimulation (DBS) of the human entorhinal area using 50 Hz pulses has revealed conflicting results regarding memory performance. Moreover, its impact on memory-related hippocampal potentials has not yet been investigated.
Methods: We recorded data from seven epilepsy patients implanted with depth electrodes in the entorhinal cortex, hippocampus, amygdala, and parahippocampal cortex. Entorhinal DBS (bipolar, biphasic 50 Hz pulses, on- and off-cycles of 15 s) was applied with low amplitude (0.1 mA) to resemble physiologic conditions. During DBS on- and off-periods, patients learned noun-color associations that were later tested.
Results: During entorhinal DBS we observed more positive deflections of event-related potentials (ranging from 700 to 950 ms) in the anterior hippocampus for the on- vs. off-condition. We detected no effects in the amygdala, mid hippocampus and parahippocampal cortex. On the behavioral level, no differences in memory performance (item and source memory) were apparent in the on- vs. off-condition, neither across all trials nor across patients.
Discussion: Our findings indicate that entorhinal DBS with low amplitude has an impact on memory encoding-related potentials within the anterior hippocampus, but not on memory performance per se.

• 出版日期2018-1