A method for recording evoked local field potentials in the primate dentate gyrus in vivo

AbstractOscillations in local field potentials (LFPs) commonly occur and analyses of them fuel brain function hypotheses. An understanding of the cellular correlates and pathways affecting LFPs is needed but many overlapping pathways in vivo makes this difficult to achieve. A prevalent LFP rhythm in the hippocampus is ‘theta’ (3-12 Hz). Theta rhythms emerge intrinsically in an in vitro whole hippocampus preparation and thus can be produced by local interactions between interneurons and pyramidal (PYR) cells. Overlapping pathways are much reduced in this preparation making it possible to decipher the contribution of different cell types to LFP generation. We focus on oriens-lacunosum/moleculare (OLM) cells as a major class of interneurons in the hippocampus. They can influence PYR cells through two distinct pathways, (i) by direct inhibition of PYR cell distal dendrites, and (ii) by indirect disinhibition of PYR cell proximal dendrites by inhibiting bistratified cells (BiCs) that target them. We use previous inhibitory network models and build biophysical LFP models using volume conductor theory. We assess the effect of OLM cells to ongoing intrinsic LFP theta rhythms by directly comparing our model LFP features with experiment. We find that robust LFP theta responses adhering to reproducible experimental criteria occur only for particular connectivities between OLM cells and BiCs. Decomposition of the LFP reveals that OLM cell inputs onto the PYR cell regulate robustness of LFP responses without affecting average power and that the robust response depends on co-activation of distal inhibition and basal excitation. We use our models to estimate the spatial extent of the region generating LFP theta rhythms, leading us to predict that about 22,000 PYR cells participate in generating the LFP theta rhythm. Besides allowing us to understand OLM cells’ contributions to intrinsic theta rhythms, our work can drive hypothesis developments of cellular contributions in vivo.Author SummaryOscillatory local field potentials (LFPs) are extracellularly recorded potentials that are widely used to interpret information processing in the brain. For example, theta LFP rhythms (3-12 Hz) are correlated with memory processing and it is known that particular inhibitory cell types control their existence. As such, it is critical for us to appreciate how various cell types contribute to the characteristics of LFP rhythms. A precise biophysical modeling scheme linking activity at the cellular level and the recorded signal has been established. However, it is difficult to assess cellular contributions in vivo because of many spatiotemporally overlapping pathways that prevent the unambiguous separation of signals. Using an in vitro preparation that exhibits intrinsic theta (3-12 Hz) rhythms and where there is much less overlap, we build biophysical LFP models to explore cell contributions to ongoing intrinsic theta rhythms. We uncover distinct contributions from different cell types and show that robust theta rhythms depend specifically on one of the cell types. We are able to determine this because our LFP models have direct links with experiment and we are able to perform thousands of simulations.

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Reconstruction of post-synaptic potentials by reverse modeling of local field potentials

10.1101/346148 ◽

2018 ◽

Author(s):

Maxime Yochum ◽

Julien Modolo ◽

Pascal Benquet ◽

Fabrice Wendling

Keyword(s):

Reverse Engineering ◽

Local Field ◽

Local Field Potentials ◽

Pyramidal Cells ◽

Synaptic Activity ◽

Neural Mass Model ◽

Field Potentials ◽

Synaptic Potentials ◽

Epileptiform Discharges

AbstractAmong electrophysiological signals, Local Field Potentials (LFPs) are extensively used to study brain activity, either in vivo or in vitro. LFPs are recorded with extracellular electrodes implanted in brain tissue. They reflect intermingled excitatory and inhibitory processes in neuronal assemblies. In cortical structures, LFPs mainly originate from the summation of post-synaptic potentials (PSPs), either excitatory (ePSPs) and inhibitory (iPSPs) generated at the level of pyramidal cells. The challenging issue, addressed in this paper, is to estimate, from a single extracellularly-recorded signal, both ePSP and iPSP components of the LFP. The proposed method is based on a model-based reverse engineering approach in which the measured LFP is fed into a physiologically-grounded neural mass model (mesoscopic level) in order to estimate the synaptic activity of a sub-population of pyramidal cells interacting with local GABAergic interneurons. The method was first validated using simulated LFPs for which excitatory and inhibitory components are known a priori and can thus serve as a ground truth. It was then evaluated on in vivo data (PTZ-induced seizures, rat; PTZ-induced excitability increase, mouse; epileptiform discharges, mouse) and on in clinico data (human seizures recorded with depth-EEG electrodes). Under these various conditions, results showed that the proposed reverse engineering method provides a reliable estimation of the average excitatory and inhibitory post-synaptic potentials at the origin of the measured LFPs. They also indicated that the method allows for monitoring of the excitation/inhibition ratio. The method has potential for multiple applications in neuroscience, typically when a time tracking of local excitability changes is required.

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Combined measurements of cerebellar blood flow, local field potentials and glucose utilization during climbing fibres stimulation: Effect of postsynaptic excitatory activity

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/sj.jcbfm.9591524.0192 ◽

2005 ◽

Vol 25 (1_suppl) ◽

pp. S192-S192

Author(s):

Aïcha Douhou ◽

Kirsten Caesar ◽

Nikolas Offenhauser ◽

Martin Lauritzen ◽

Gilles Bonvento

Keyword(s):

Blood Flow ◽

Local Field ◽

Glucose Utilization ◽

Local Field Potentials ◽

Field Potentials ◽

Climbing Fibres ◽

Excitatory Activity ◽

Combined Measurements

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Local field potentials of the bed nucleus of stria terminalis in patients with major depressive and obsessive compulsive disorder

Klinische Neurophysiologie ◽

10.1055/s-0033-1337276 ◽

2013 ◽

Vol 44 (01) ◽

Cited By ~ 1

Author(s):

WJ Neumann ◽

J Huebl ◽

C Brücke ◽

L Gabriëls ◽

P Brown ◽

...

Keyword(s):

Obsessive Compulsive Disorder ◽

Local Field ◽

Local Field Potentials ◽

Stria Terminalis ◽

Field Potentials ◽

Obsessive Compulsive ◽

Major Depressive ◽

Bed Nucleus ◽

Compulsive Disorder

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

Brain Sciences ◽

10.3390/brainsci11070882 ◽

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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