Dopaminergic stimulation facilitates working memory and differentially affects prefrontal low theta oscillations

TY - JOUR

T1 - Dopaminergic stimulation facilitates working memory and differentially affects prefrontal low theta oscillations

AU - Eckart, Cindy

AU - Fuentemilla, Lluís

AU - Bauch, Eva M

AU - Bunzeck, Nico

N1 - Copyright © 2014 Elsevier Inc. All rights reserved.

PY - 2014/7/1

Y1 - 2014/7/1

N2 - We used electroencephalography (EEG) together with psychopharmacological stimulation to investigate the role of dopamine in neural oscillations during working memory (WM). Following a within-subjects design, healthy humans either received the dopamine precursor L-Dopa (150 mg) or a placebo before they performed a Sternberg WM paradigm. Here, sequences of sample images had to be memorized for a delay of 5 s in three different load conditions (two, four or six items). On the next day, long-term memory (LTM) for the images was tested. Behaviorally, L-Dopa improved WM and LTM performance as a function of WM load. More precisely, there was a specific drug effect in the four-load condition with faster reaction times to the probe in the WM task and higher corrected hit-rates in the LTM task. During the maintenance period, there was a linear and quadratic effect of WM load on power in the high theta (5-8 Hz) and alpha (9-14 Hz) frequency range at frontal sensors. Importantly, a drug by load interaction--mimicking the behavioral results--was found only in low theta power (2-4 Hz). As such, our results indicate a specific link between prefrontal low theta oscillations, dopaminergic neuromodulation during WM and subsequent LTM performance.

AB - We used electroencephalography (EEG) together with psychopharmacological stimulation to investigate the role of dopamine in neural oscillations during working memory (WM). Following a within-subjects design, healthy humans either received the dopamine precursor L-Dopa (150 mg) or a placebo before they performed a Sternberg WM paradigm. Here, sequences of sample images had to be memorized for a delay of 5 s in three different load conditions (two, four or six items). On the next day, long-term memory (LTM) for the images was tested. Behaviorally, L-Dopa improved WM and LTM performance as a function of WM load. More precisely, there was a specific drug effect in the four-load condition with faster reaction times to the probe in the WM task and higher corrected hit-rates in the LTM task. During the maintenance period, there was a linear and quadratic effect of WM load on power in the high theta (5-8 Hz) and alpha (9-14 Hz) frequency range at frontal sensors. Importantly, a drug by load interaction--mimicking the behavioral results--was found only in low theta power (2-4 Hz). As such, our results indicate a specific link between prefrontal low theta oscillations, dopaminergic neuromodulation during WM and subsequent LTM performance.

KW - Adult

KW - Biological Clocks

KW - Brain Mapping

KW - Dopamine

KW - Dopamine Agents

KW - Dopaminergic Neurons

KW - Double-Blind Method

KW - Female

KW - Humans

KW - Levodopa

KW - Long-Term Potentiation

KW - Male

KW - Memory, Short-Term

KW - Nerve Net

KW - Prefrontal Cortex

KW - Task Performance and Analysis

KW - Theta Rhythm

U2 - 10.1016/j.neuroimage.2014.03.011

DO - 10.1016/j.neuroimage.2014.03.011

M3 - SCORING: Journal article

C2 - 24642289

VL - 94

SP - 185

EP - 192

JO - NEUROIMAGE

JF - NEUROIMAGE

SN - 1053-8119

ER -