Theory of current source-density analysis and determination of conductivity tensor for anuran cerebellum

Nicholson, Charles; Freeman, John A.

doi:10.1152/jn.1975.38.2.356

Cited by 664 publications

(499 citation statements)

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“…Such currents are measured experimentally by electrodes in the neural tissue and the corresponding potentials are the LFPs. Consequently LFPs reflect the dendritic currents or correspondingly the membrane potentials on the dendrites (Nicholson and Freeman 1975;Freeman 1992). Since the EEG represents the spatial average of the dendritic activity (Nunez 2000), we consider the effective membrane potential u(x,t) = u e (x,t) -u i (x,t) which is proportional to the dendritic currents, see e.g.…”

Section: The Resting Statementioning

confidence: 99%

Effects of the anesthetic agent propofol on neural populations

Hutt

Longtin

2009

Cogn Neurodyn

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The neuronal mechanisms of general anesthesia are still poorly understood. Besides several characteristic features of anesthesia observed in experiments, a prominent effect is the bi-phasic change of power in the observed electroencephalogram (EEG), i.e. the initial increase and subsequent decrease of the EEG-power in several frequency bands while increasing the concentration of the anaesthetic agent. The present work aims to derive analytical conditions for this bi-phasic spectral behavior by the study of a neural population model. This model describes mathematically the effective membrane potential and involves excitatory and inhibitory synapses, excitatory and inhibitory cells, nonlocal spatial interactions and a finite axonal conduction speed. The work derives conditions for synaptic time constants based on experimental results and gives conditions on the resting state stability. Further the power spectrum of Local Field Potentials and EEG generated by the neural activity is derived analytically and allow for the detailed study of bi-spectral power changes. We find bi-phasic power changes both in monostable and bistable system regime, affirming the omnipresence of bi-spectral power changes in anesthesia. Further the work gives conditions for the strong increase of power in the d-frequency band for large propofol concentrations as observed in experiments.

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Section: The Resting Statementioning

confidence: 99%

Effects of the anesthetic agent propofol on neural populations

Hutt

Longtin

2009

Cogn Neurodyn

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“…Population trans-membrane current flows were estimated using CSD analysis (Nicholson and Freeman, 1975), calculated as the second spatial derivative of field potentials (0.5-30Hz) after applying a 5-point Hamming filter (Ulbert et al, 2001a). Although the transmembrane currents localized with CSD are generally interpreted as due to transynaptic currents (Mitzdorf, 1985), voltage-gated currents may also contribute (Murakami et al, 2002).…”

Section: Recordings and Analysismentioning

confidence: 99%

“…When CSD current sinks are generated by excitatory post-synaptic currents (EPSCs), they generally are accompanied by passive return current sources (Nicholson and Freeman, 1975). Conversely, at the normal depolarized state of cortical neurons (Destexhe et al, 2003), inhibitory post-synaptic currents (IPSCs) could produce active current sources, and they would be accompanied by a passive current sink.…”

Section: Perirhinal Cortex (Pr)mentioning

confidence: 99%

Processing stages underlying word recognition in the anteroventral temporal lobe

et al. 2006

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The anteroventral temporal lobe integrates visual, lexical, semantic and mnestic aspects of wordprocessing, through its reciprocal connections with the ventral visual stream, language areas, and the hippocampal formation. We used linear microelectrode arrays to probe population synaptic currents and neuronal firing in different cortical layers of the anteroventral temporal lobe, during semantic judgments with implicit priming, and overt word recognition. Since different extrinsic and associative inputs preferentially target different cortical layers, this method can help reveal the sequence and nature of local processing stages at a higher resolution than was previously possible.The initial response in inferotemporal and perirhinal cortices is a brief current sink beginning at 120ms, and peaking at ~170ms. Localization of this initial sink to middle layers suggests that it represents feedforward input from lower visual areas, and simultaneously increased firing implies that it represents excitatory synaptic currents. Until ~800ms, the main focus of transmembrane current sinks alternates between middle and superficial layers, with the superficial focus becoming increasingly dominant after ~550ms. Since superficial layers are the target of local and feedback associative inputs, this suggests an alternation in predominant synaptic input between feedforward and feedback modes. Word repetition does not affect the initial perirhinal and inferotemporal middle layer sink, but does decrease later activity. Entorhinal activity begins later (~200ms), with greater apparent excitatory postsynaptic currents and multiunit activity in neocortically-projecting than hippocampal-projecting layers. In contrast to perirhinal and entorhinal responses, entorhinal responses are larger to repeated words during memory retrieval.These results identify a sequence of physiological activation, beginning with a sharp activation from lower level visual areas carrying specific information to middle layers. This is followed by feedback and associative interactions involving upper cortical layers, which are abbreviated to repeated words. Following bottom-up and associative stages, top-down recollective processes may be driven by entorhinal cortex. Word processing involves a systematic sequence of fast feedforward information transfer from visual areas to anteroventral temporal cortex, followed by prolonged interactions of this feedforward information with local associations, and feedback mnestic information from the medial temporal lobe.

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“…CSD analysis provides an approximation of summed transmembrane currents in vertically arranged structures Nicholson and Freeman, 1975), including the hippocampus and neocortex. The general disadvantage of this approach compared to electrodes with a sharp tip is that the recording contacts are located on the shaft formed by the cut end of the wire electrodes.…”

Section: Laminar Recording Techniquementioning

confidence: 99%

Intracranial neuronal ensemble recordings and analysis in epilepsy

Tóth

Fabó

Entz

et al. 2016

Journal of Neuroscience Methods

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Pathological neuronal firing was demonstrated 50 years ago as the hallmark of epileptically transformed cortex with the use of implanted microelectrodes. Since then, microelectrodes remained only experimental tools in humans to detect unitary neuronal activity to reveal physiological and pathological brain functions. This recording technique has evolved substantially in the past few decades; however, based on recent human data implying their usefulness as diagnostic tools, we expect a substantial increase in the development of microelectrodes in the near future.Here, we review the technological background and history of microelectrode array development for human examinations in epilepsy, including discussions on of wire-based and microelectrode arrays fabricated using micro-electro-mechanical system (MEMS) techniques and novel future techniques to record neuronal ensemble.We give an overview of clinical and surgical considerations, and try to provide a list of probes on the market with their availability for human recording. 2Then finally, we briefly review the literature on modulation of single neuron for the treatment of epilepsy, and highlight the current topics under examination that can be background for the future development.3

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Theory of current source-density analysis and determination of conductivity tensor for anuran cerebellum

Cited by 664 publications

References 0 publications

Effects of the anesthetic agent propofol on neural populations

Effects of the anesthetic agent propofol on neural populations

Processing stages underlying word recognition in the anteroventral temporal lobe

Intracranial neuronal ensemble recordings and analysis in epilepsy

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