Biology subjects

Poetter-Nerger, M.

Publications and source records attributed to Poetter-Nerger, M..

3 recordsLinked to original sources

bioRxiv2026

Cortical E-fields of deep brain stimulation in Parkinson's disease patients exceed typical E-field magnitudes of transcranial electrical stimulation

BackgroundDeep brain stimulation (DBS) is an established and effective intervention for Parkinsons disease. Although the exact mechanisms of action are still unclear, both therapeutic benefits and side effects are solely attributed to neuromodulation via strong electric fields (E-fields) in the surgical target. Nevertheless, DBS generates E-fields that extend beyond the stimulation site and can be detected throughout the brain. Recent evidence from transcranial electrical stimulation studies shows that weak cortical E-fields even below 1 V/m can have a neuromodulatory effect, raising the question of a physiological relevance of weak cortical fields of DBS. However, the strength of cortical E-fields of DBS is currently unknown. ObjectiveUsing a novel framework, we aimed to quantify the whole-brain E-field distribution in patients with Parkinsons disease receiving therapeutic DBS of the subthalamic nucleus (STN-DBS). MethodsIn this work, we developed a pipeline to simulate DBS E-field distributions throughout the brain, based on the existing open-source toolboxes Lead-DBS and SimNIBS. We constructed patient-specific whole-head models including electrode leads for 25 patients with Parkinsons disease receiving subthalamic DBS, and simulated E-fields using the patients clinical stimulation settings for 49 hemispheres. ResultsWe found that median peak E-field magnitudes exceeded 0.3 V/m in all cortical regions and were greater than 1 V/m in the orbital gyrus, superior temporal gyrus, fusiform gyrus, parahippocampal gyrus, insular gyrus, cingulate gyrus. Most prominently, the orbital and insular gyri showed peak magnitudes ranging from 0.81 to 8.61 V/m and 0.90 to 8.01 V/m. ConclusionsOur results indicate that the E-fields of STN-DBS reach cortical peak magnitudes that exceed typically reported values of transcranial electrical stimulation. This opens the possibility that weak E-fields of DBS could have a direct neuromodulatory effect in wider regions of the brain, for example in cortical regions.

neuroscience↗

bioRxiv2025

Modulation of temporal prediction by STN-DBS in Parkinson's disease: Links between behavior and cortical oscillations

BACKGROUNDAccurate temporal prediction is essential for adaptive behavior and relies on coordinated neural activity within cortico-basal ganglia circuits. Parkinsons disease (PD), with the main hallmark of dopaminergic depletion and abnormal neural synchrony, impairs this ability. Deep brain stimulation deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a widely used treatment for reducing motor symptoms in PD, but its effects on temporal prediction remain not fully understood. OBJECTIVESThis study aimed to investigate how STN-DBS influences temporal prediction performance and its underlying oscillatory dynamics in PD patients, with a particular focus on beta-band power and delta-band inter-trial phase consistency (ITPC). METHODS13 PD patients (5 female, age: 64 {+/-} 5.7 years; disease duration: 11.8 {+/-} 1.8 years) with STN-DBS performed a temporal prediction task with (DBS ON) and without (DBS OFF) stimulation, while 64-channel-electroencephalography (EEG) was recorded. 20 age-matched healthy controls completed the same task. Behavioral performance was assessed using psychometric function slopes. Time-frequency analyses and source-level EEG measures examined beta power and delta ITPC. RESULTSPD patients showed impaired temporal prediction performance compared to controls, reflected in shallower psychometric slopes. DBS significantly improved performance to a level comparable to those of controls. EEG revealed reduced beta suppression in PD patients during DBS OFF, while beta suppression in DBS ON was comparable to controls. Both DBS OFF and ON exhibited reduced delta ITPC compared to controls. In DBS ON, source-level delta ITPC was positively correlated with temporal prediction accuracy. CONCLUSIONSTN-DBS improves temporal prediction performance in PD, likely through modulation of beta and delta oscillatory activity. While beta power suppression is partially restored, deficits in delta phase alignment persist, suggesting frequency-specific DBS effects on temporal prediction processes.

neuroscience↗

bioRxiv2019

Parkinsons disease uncovers an underlying sensitivity of subthalamic nucleus neurons to beta-frequency cortical input

Abnormally sustained beta-frequency synchronisation between the motor cortex and subthalamic nucleus (STN) is associated with motor symptoms in Parkinsons disease (PD). It is currently unclear whether STN neurons have a preference for beta-frequency input (12-35Hz), rather than cortical input at other frequencies, and how such a preference would arise following dopamine depletion. To address this question, we combined analysis of cortical and STN recordings from awake PD patients undergoing deep brain stimulation surgery with recordings of identified STN neurons in anaesthetised rats. In PD patients, we demonstrate that a subset of STN neurons are strongly and selectively sensitive to fluctuations of cortical beta oscillations over time, linearly increasing their phase-locking strength with respect to full range of instantaneous amplitude. In rats, we probed the frequency response of STN neurons more precisely, by recording spikes evoked by short bursts of cortical stimulation with variable frequency (4-40Hz) and constant amplitude. In both healthy and dopamine-depleted animals, only beta-frequency stimulation selectively led to a progressive reduction in the variability of spike timing through the stimulation train. We hypothesize, that abnormal activation of the indirect pathway, via dopamine depletion and/or cortical stimulation, could trigger an underlying sensitivity of the STN microcircuit to beta-frequency input.

neuroscience↗