scholarly journals Inverse current source solutions from single cells to local field potentials

2010 ◽  
Vol 4 ◽  
Author(s):  
Érdi Péter
Keyword(s):  
Local Field ◽  
Single Cells ◽  
Current Source ◽  
Local Field Potentials ◽  
Field Potentials

scholarly journals Sensing Local Field Potentials with a Directional and Scalable Depth Array: DISC

2021 ◽  
Author(s):  
Amada Abrego Mancilla ◽  
Wasif Khan ◽  
Christopher E Wright ◽  
Neela Prajapati ◽  
M Rabiul Islam ◽  
...  
Keyword(s):  
Local Field ◽  
Barrel Cortex ◽  
Current Source ◽  
Local Field Potentials ◽  
Brain Targeting ◽  
Directional Sensitivity ◽  
Cortical Region ◽  
Field Potentials ◽  
Electromagnetic Modeling ◽  
Functional Therapy

A variety of electrophysiology tools are available to the neurosurgeon for diagnosis, functional therapy, and neural prosthetics. However, no tool can currently address these three critical recording needs: (i) a surgical method that can reach any cortical region in a minimally invasive manner; (ii) record microscale, mesoscale, and macroscale resolutions simultaneously; and (iii) enable recording from multiple brain regions. This work presents a novel device for recording local field potentials (LFPs) whose form is based on state-of-the-art stereo-electroencephalogram (sEEG). Using quasi-static electromagnetic modeling, the lead body is shown to shield LFP sources and this enables directional sensitivity and scalability when microelectrodes are positioned radially, which we refer to as a DISC array. As predicted, DISC demonstrated significantly improved signal-to-noise, directional sensitivity, and decoding accuracy in the rat barrel cortex during whisker stimulation. Critically, DISC also demonstrated equivalent fidelity at the macroscale and, uniquely, performs current source density in stereo. Directional sensitivity of LFPs may significantly improve brain-computer interfaces and many diagnostic procedures, including epilepsy foci detection and deep brain targeting.

scholarly journals Phase-amplitude coupling, an indication of bursting in parkinsonism, is masked by periodic pulses

2016 ◽  
Vol 115 (3) ◽  
pp. 1587-1595 ◽  
Author(s):  
Teresa H. Sanders
Keyword(s):  
Animal Models ◽  
Subthalamic Nucleus ◽  
Local Field ◽  
Cell Model ◽  
Single Cells ◽  
Local Field Potentials ◽  
Masking Effect ◽  
Field Potentials ◽  
A Cell ◽  
Phase Amplitude

Interactions between neural oscillations in the brain have been observed in many structures including the hippocampus, amygdala, motor cortex, and basal ganglia. In this study, one popular approach for quantifying oscillation interactions was considered: phase-amplitude coupling. The goals of the study were to use simulations to examine potential causes of elevated phase-amplitude coupling in parkinsonism, to compare simulated parkinsonian signals with recorded local field potentials from animal models of parkinsonism, to investigate possible relationships between increased bursting in parkinsonian single cells and elevated phase-amplitude coupling, and to uncover potential noise and artifact effects. First, a cell model that integrates incremental input currents and fires at realistic voltage thresholds was modified to allow control of stochastic parameters related to firing and burst rates. Next, the input currents and distribution of integration times were set to reproduce firing patterns consistent with those from parkinsonian subthalamic nucleus cells. Then, local field potentials were synthesized from the output of multiple simulated cells with varying degrees of synchronization and compared with subthalamic nucleus recordings from animal models of parkinsonism. The results showed that phase-amplitude coupling can provide important information about underlying neural activity. In particular, signals synthesized from synchronized bursting neurons showed increased oscillatory interactions similar to those observed in parkinsonian animals. Additionally, changes in bursting parameters such as the intraburst rate, the mean interburst period, and the amount of synchronization between neurons influenced the phase-amplitude coupling in predictable ways. Finally, simulation results revealed that small periodic signals can have a surprisingly large masking effect on phase-amplitude coupling.

Muscimol and baclofen differentially suppress retinotopic and nonretinotopic responses in visual cortex

2005 ◽  
Vol 22 (6) ◽  
pp. 839-858 ◽  
Author(s):  
TAKUJI KASAMATSU ◽  
KEIKO MIZOBE ◽  
ERICH E. SUTTER
Keyword(s):  
Visual Cortex ◽  
Long Range ◽  
Local Field ◽  
Receptor Agonist ◽  
Single Cells ◽  
Receptive Fields ◽  
Local Field Potentials ◽  
Field Potentials ◽  
Basal Dendrites ◽  
Stimulation Of

This study relates to local field potentials and single-unit responses in cat visual cortex elicited by contrast reversal of bar gratings that were presented in single, double, or multiple discrete patch (es) of the visual field. Concurrent stimulation of many patches by means of the pseudorandom, binary m-sequence technique revealed interactions between their respective responses. An analysis identified two distinct components of local field potentials: a fast local component (FLC) and a slow distributed component (SDC). The FLC is thought to be a primarily postsynaptic response, as judged by its relatively short latency. It is directly generated by thalamocortical volleys following retinotopic stimulation of receptive fields of a small cluster of single cells, combined with responses to recurrent excitation and inhibition derived from the cells under study and immediately neighboring cells. In contrast, the SDC is thought to be an aggregate of dendritic potentials related to the long-range lateral connections (i.e. long-range coupling). We compared the suppressive effects of a GABAA-receptor agonist, muscimol, on the FLC and SDC with those of a GABAB-receptor agonist, baclofen, and found that muscimol more strongly suppressed the FLC than the SDC, and that the reverse was the case for baclofen. The differential suppression of the FLC and SDC found in the present study is consistent with the notion that intracortical electrical signals related to the FLC terminate on the somata and proximal/basal dendrites, while those related to the SDC terminate on distal dendrites.

scholarly journals Altered Emotional Phenotypes in Chronic Kidney Disease Following 5/6 Nephrectomy

2021 ◽  
Vol 11 (7) ◽  
pp. 882
Author(s):  
Yeon Hee Yu ◽  
Seong-Wook Kim ◽  
Dae-Kyoon Park ◽  
Ho-Yeon Song ◽  
Duk-Soo Kim ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Local Field ◽  
Smooth Muscle Actin ◽  
Local Field Potentials ◽  
Renal Tissue ◽  
Field Potentials ◽  
Wild Type ◽  
Sprague Dawley ◽  
Rat Models

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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