scholarly journals Local field potentials in the parietal reach region reveal mechanisms of bimanual coordination

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eric Mooshagian ◽  
Charles D. Holmes ◽  
Lawrence H. Snyder

AbstractPrimates use their arms in complex ways that frequently require coordination between the two arms. Yet the planning of bimanual movements has not been well-studied. We recorded spikes and local field potentials (LFP) from the parietal reach region (PRR) in both hemispheres simultaneously while monkeys planned and executed unimanual and bimanual reaches. From analyses of interhemispheric LFP-LFP and spike-LFP coherence, we found that task-specific information is shared across hemispheres in a frequency-specific manner. This shared information could arise from common input or from direct communication. The population average unit activity in PRR, representing PRR output, encodes only planned contralateral arm movements while beta-band LFP power, a putative PRR input, reflects the pattern of planned bimanual movement. A parsimonious interpretation of these data is that PRR integrates information about the movement of the left and right limbs, perhaps in service of bimanual coordination.

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Ilknur Telkes ◽  
Jennifer Durphy ◽  
Octavian Adam ◽  
Nataly Raviv ◽  
Julie G Pilitsis

Abstract INTRODUCTION One of the biggest limitations of deep brain stimulation (DBS) therapy is the stimulation induced side effects due to restricted size of functional areas in subthalamic nucleus (STN) and the proximity of structures. The segmented DBS lead technology aims to address this problem by delivering more selected, focal modulation via smaller, directional contacts. However, the DBS programming becomes more complex and time-consuming for clinical feasibility. Here in this pilot study, we investigated the spectral power distribution of directional local field potentials (LFPs) in STN and their relationship to motor symptoms of Parkinson disease (PD). METHODS We recorded 8-channel intraoperative LFPs in 9 PD patients at resting and during stimulation OFF. Power-frequency spectra were computed for all individual contacts and then grouped according to which anatomical directions they are facing. Beta (13-20 Hz/20-35 Hz) and alpha (7-12 Hz) band powers were calculated and their correlation to preoperative UPDRS-3 scores (51.7 ± 21.9 d before the DBS surgery) and the clinical programming were evaluated. RESULTS The average depth-frequency maps demonstrated different spectral dynamics across anterior, medial, and lateral directions. Patients with severe tremor compared to nontremor subjects showed higher beta power in anterior and lateral directions. Beta band power were positively correlated with the tremor severity and significantly correlated with clinical stimulation amplitude (mA) in anterior direction (P < .05). Correlation analysis between beta power and the other UPDRS-3 items such as bradykinesia/rigidity or postural instability and gait disturbance did not show clear trends towards a direction. CONCLUSION Given that testing all possible combinations of contact pairs and stimulation parameters is not feasible in a single clinic visit, spatio-spectral dynamics obtained from intraoperative recordings of LFPs might be used as an initial marker to select optimal contact (s). LFPs carry pathological signatures of PD and they might provide a functional use to predict optimal stimulation parameters in future. These features as well as higher frequency and cross-coupling dynamics of LFPs need to be studied in detail with larger subject populations.


2016 ◽  
Author(s):  
M. von Papen ◽  
H. Dafsari ◽  
E. Florin ◽  
F. Gerick ◽  
L. Timmermann ◽  
...  

AbstractLocal field potentials (LFP) reflect the integrated electrophysiological activity of a large group of neurons. To minimize influence of external activity on the analysis, conventionally bipolar recordings are used to eliminate volume-conducted signals. Here we introduce a novel method, called phase-coherence classification (PCC), to separate LFP in time-frequency domain into a volume-conducted, a local incoherent and local coherent signal. The PCC allows to compute the power spectral densities of each signal and to associate each class with possible locations of electro-physiological activity. In order to test the resolution properties and accuracy of the method we generate composite and non-stationary synthetic time series with similar statistical characteristics as measured LFP. The PCC identifies volume-conducted signals with a phase threshold that is determined from probability density functions of non-phase-shifted synthetic time series. We estimate optimal PCC parameters for the analysis of beta band oscillations in LFP and apply the PCC to a test data set obtained from within the subthalamic nucleus of eight patients with Parkinson’s disease (PD). We show that PCC can identify activity of multiple local clusters during a tremor episode and quantify the relative power of local and volume-conducted signals. We further analyze the electrophysiological response to an apomorphine injection during rest and show that incoherent activity in the low beta band shows a significant medication-induced decrease. We further find significant movement-induced changes on medication of the local coherent signal, which increased during an isometric hold task and decreased during phasic wrist movement. This indicates a different role of incoherent and coherent signals possibly related to physiologically different networks. This new PCC method can potentially also be applied to EEG and MEG data in order to minimize the influence of spatial leakage on power spectra and coherence estimates.


2020 ◽  
Vol 163 (1) ◽  
pp. 205-209 ◽  
Author(s):  
Thomas Koeglsperger ◽  
Jan H. Mehrkens ◽  
Kai Bötzel

AbstractSubthalamic local field potentials in the beta band are considered as potential biomarkers for closed-loop deep brain stimulation. To investigate the subthalamic beta band peak amplitudes in a Parkinson’s disease patient over an extended period of time by using a novel and commercially available neurostimulator with permanent sensing capability. We recorded local field potentials of the subthalamic nucleus using the Medtronic Percept™ implantable neurostimulator at rest and during physical activity (gait) with and in response to deep brain stimulation. We found a double-peaked beta activity on both sides. Increasing stimulation and physical activity resulted in a decreased beta band amplitude, but was accompanied by the appearance of a second, and previously unrecognized peak at 13 Hz in the right hemisphere. Our results will support the investigation of distinct different peaks in the beta band and their relevance and usefulness as closed-loop biomarkers.


2018 ◽  
Vol 115 (36) ◽  
pp. E8567-E8576 ◽  
Author(s):  
Ilknur Telkes ◽  
Ashwin Viswanathan ◽  
Joohi Jimenez-Shahed ◽  
Aviva Abosch ◽  
Musa Ozturk ◽  
...  

Although motor subtypes of Parkinson’s disease (PD), such as tremor dominant (TD) and postural instability and gait difficulty (PIGD), have been defined based on symptoms since the mid-1990s, no underlying neural correlates of these clinical subtypes have yet been identified. Very limited data exist regarding the electrophysiological abnormalities within the subthalamic nucleus (STN) that likely accompany the symptom severity or the phenotype of PD. Here, we show that activity in subbands of local field potentials (LFPs) recorded with multiple microelectrodes from subterritories of STN provide distinguishing neurophysiological information about the motor subtypes of PD. We studied 24 patients with PD and found distinct patterns between TD (n = 13) and PIGD (n = 11) groups in high-frequency oscillations (HFOs) and their nonlinear interactions with beta band in the superior and inferior regions of the STN. Particularly, in the superior region of STN, the power of the slow HFO (sHFO) (200–260 Hz) and the coupling of its amplitude with beta-band phase were significantly stronger in the TD group. The inferior region of STN exhibited fast HFOs (fHFOs) (260–450 Hz), which have a significantly higher center frequency in the PIGD group. The cross-frequency coupling between fHFOs and beta band in the inferior region of STN was significantly stronger in the PIGD group. Our results indicate that the spatiospectral dynamics of STN-LFPs can be used as an objective method to distinguish these two motor subtypes of PD. These observations might lead to the development of sensing and stimulation strategies targeting the subterritories of STN for the personalization of deep-brain stimulation (DBS).


2001 ◽  
Vol 140 (1) ◽  
pp. 46-55 ◽  
Author(s):  
O. Donchin ◽  
A. Gribova ◽  
O. Steinberg ◽  
H. Bergman ◽  
Cardoso de Oliveira ◽  
...  

2021 ◽  
Vol 11 (7) ◽  
pp. 882
Author(s):  
Yeon Hee Yu ◽  
Seong-Wook Kim ◽  
Dae-Kyoon Park ◽  
Ho-Yeon Song ◽  
Duk-Soo Kim ◽  
...  

Increased prevalence of chronic kidney disease (CKD) and neurological disorders including cerebrovascular disease, cognitive impairment, peripheral neuropathy, and dysfunction of central nervous system have been reported during the natural history of CKD. Psychological distress and depression are serious concerns in patients with CKD. However, the relevance of CKD due to decline in renal function and the pathophysiology of emotional deterioration is not clear. Male Sprague Dawley rats were divided into three groups: sham control, 5/6 nephrectomy at 4 weeks, and 5/6 nephrectomy at 10 weeks. Behavior tests, local field potentials, and histology and laboratory tests were conducted and investigated. We provided direct evidence showing that CKD rat models exhibited anxiogenic behaviors and depression-like phenotypes, along with altered hippocampal neural oscillations at 1–12 Hz. We generated CKD rat models by performing 5/6 nephrectomy, and identified higher level of serum creatinine and blood urea nitrogen (BUN) in CKD rats than in wild-type, depending on time. In addition, the level of α-smooth muscle actin (α-SMA) and collagen I for renal tissue was markedly elevated, with worsening fibrosis due to renal failures. The level of anxiety and depression-like behaviors increased in the 10-week CKD rat models compared with the 4-week rat models. In the recording of local field potentials, the power of delta (1–4 Hz), theta (4–7 Hz), and alpha rhythm (7–12 Hz) was significantly increased in the hippocampus of CKD rats compared with wild-type rats. Together, our findings indicated that anxiogenic behaviors and depression can be induced by CKD, and these abnormal symptoms can be worsened as the onset of CKD was prolonged. In conclusion, our results show that the hippocampus is vulnerable to uremia.


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