A new probe to monitor the effects of drugs on local field potentials

Darbin, Olivier; Newton, Lauren; Wichmann, Thomas

doi:10.1016/j.jneumeth.2006.01.010

Cited by 10 publications

(10 citation statements)

References 16 publications

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“…The dose was based on a previous report that local intrastriatal perfusion of 10 μM gabazine in monkey brain for 20 min induced prominent spike-wave activity without behavioral changes or other EEG abnormalities (Darbin et al, 2006). The wave patterns in vivo (Fig.…”

Section: Discussionmentioning

confidence: 99%

Disinhibition reduces extracellular glutamine and elevates extracellular glutamate in rat hippocampus in vivo

Kanamori

2015

Epilepsy Research

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Disinhibition was induced in the hippocampal CA1/CA3 region of normal adult rats by unilateral perfusion of the GABAAR antagonist, 4-[6-imino-3-(4-methoxyphenyl)pyridazin-1-yl]butanoic acid hydrobromide (gabazine), or a GABABR antagonist, p-(3-aminopropyl)-p-diethoxymethyl-phosphinic acid (CGP 35348), through a microdialysis probe. Effects of disinhibition on EEG recordings and the concentrations of extracellular glutamate (GLUECF), the major excitatory neurotransmitter, and of extracellular glutamine (GLNECF), its precursor, were examined bilaterally in freely-behaving rats. Unilateral perfusion of 10 μM gabazine in artificial CSF of normal electrolyte composition for 34 min induced epileptiform discharges which represent synchronized glutamatergic population bursts, not only in the gabazine-perfused ipsilateral hippocampus, but also in the aCSF-perfused contralateral hippocampus. The concentration of GLUECF remained unchanged, but the concentration of its precursor, GLNECF, decreased to 73 ± 4% (n = 5) of the baseline during frequent epileptiform discharges, not only in the ipsilateral, but also in the contralateral hippocampus, where the change can be attributed to recurrent epileptiform discharges per se, with recovery to 95% of baseline when epileptiform discharges diminished. The blockade of GABABR, by CGP 35348 perfusion in the ipsilateral hippocampus for 30 min, induced bilateral Na+ spikes in extracellular recording. These can reasonably be attributed to somatic and dendritic action potentials and are indicative of synchronized excitatory activity. This disinhibition induced, in both hippocampi, (a) transient 1.6 to 2.4- fold elevation of GLUECF which correlated with the number of Na+ spike cluster events and (b) concomitant reduction of GLNECF to ~70%. Intracellular GLN concentration was measured in the hippocampal CA1/CA3 region sampled by microdialysis in separate groups of rats by snap-freezing the brain after 25 min of gabazine perfusion or 20 min of CGP perfusion when extracellular GLN (GLNECF) was 60-70% of the pre-perfusion level. These intracellular GLN concentrations in the disinhibited hippocampi showed no statistically significant difference from the untreated control. This result strongly suggests that the observed decrease of GLNECF is not due to reduced glutamine synthesis or decrease in the rate of efflux of GLN to ECF. This strengthens the likelihood that reduced GLNECF reflects increased GLN uptake into neurons to sustain enhanced GLU flux during excitatory population bursts in disinhibited hippocampus. The results are consistent with the emerging concept that neuronal uptake of GLNECF plays a major role in sustaining epileptiform activities in the kainate-induced model of temporal-lobe epilepsy.

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Section: Discussionmentioning

confidence: 99%

Disinhibition reduces extracellular glutamine and elevates extracellular glutamate in rat hippocampus in vivo

Kanamori

2015

Epilepsy Research

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“…A systemic evaluation of the main neurotransmitters on the non-linear dynamic of basal ganglia neurons is necessary to draw a non-linear functional-anatomical model of the motor circuitry both in the normal and the pathological conditions. Single unit recordings combined with LFPs in an animal model for movement disorders (82, 83), and in patients (84), will certainly help to progress in this research direction.…”

Section: Discussionmentioning

confidence: 99%

Non-Linear Dynamics in Parkinsonism

et al. 2013

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Over the last 30 years, the functions (and dysfunctions) of the sensory-motor circuitry have been mostly conceptualized using linear modelizations which have resulted in two main models: the “rate hypothesis” and the “oscillatory hypothesis.” In these two models, the basal ganglia data stream is envisaged as a random temporal combination of independent simple patterns issued from its probability distribution of interval interspikes or its spectrum of frequencies respectively. More recently, non-linear analyses have been introduced in the modelization of motor circuitry activities, and they have provided evidences that complex temporal organizations exist in basal ganglia neuronal activities. Regarding movement disorders, these complex temporal organizations in the basal ganglia data stream differ between conditions (i.e., parkinsonism, dyskinesia, healthy control) and are responsive to treatments (i.e., l-DOPA, deep brain stimulation). A body of evidence has reported that basal ganglia neuronal entropy (a marker for complexity/irregularity in time series) is higher in hypokinetic state. In line with these findings, an entropy-based model has been recently formulated to introduce basal ganglia entropy as a marker for the alteration of motor processing and a factor of motor inhibition. Importantly, non-linear features have also been identified as a marker of condition and/or treatment effects in brain global signals (EEG), muscular activities (EMG), or kinetic of motor symptoms (tremor, gait) of patients with movement disorders. It is therefore warranted that the non-linear dynamics of motor circuitry will contribute to a better understanding of the neuronal dysfunctions underlying the spectrum of parkinsonian motor symptoms including tremor, rigidity, and hypokinesia.

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“…Recordings from these arrays in the striatum of urethane-anesthetized rats revealed spatial heterogeneity of electrically-evoked dopamine and spatiotemporal parallels between recording modalities. While there are reports describing microdialysis measurements with LFP recordings made from electrodes implanted outside (Fried et al, 1999; Ludvig et al, 1992) or inside the microdialysis tubing (Darbin et al, 2006; Obrenovitch et al, 1993), to our knowledge measuring neurotransmitter levels and LFPs at the same spatiotemporal scale through microfabricated arrays is a novel approach. In this parallel scheme, a constant bias potential sufficient to oxidize dopamine was applied independently at multiple platinum sites across the array with currents sampled every 16 ms.…”

Section: Discussionmentioning

confidence: 99%

“…Understanding the rhythmic generation and amplification of LFPs in the intact brain may benefit from techniques that can simultaneously monitor neurotransmitter dynamics. An approach to examine correlations between tonic neurotransmitter concentrations assessed through microdialysis and local field potentials (LFPs) has been suggested previously (Darbin et al, 2006). However, to examine high-frequency oscillations, which are often transient, sampling neurotransmitter levels requires a faster approach such as in vivo electrochemistry (Adams, 1976; Boulton et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

Implantable microelectrode arrays for simultaneous electrophysiological and neurochemical recordings

Johnson¹,

Franklin²,

Gibson³

et al. 2008

Journal of Neuroscience Methods

101

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Implantable microfabricated microelectrode arrays represent a versatile and powerful tool to record electrophysiological activity across multiple spatial locations in the brain. Spikes and field potentials, however, correspond to only a fraction of the physiological information available at the neural interface. In urethane-anesthetized rats, microfabricated microelectrode arrays were implanted acutely for simultaneous recording of striatal local field potentials, spikes, and electrically-evoked dopamine overflow on the same spatiotemporal scale. During these multi-modal recordings we observed 1) that the amperometric method used to detect dopamine did not significantly influence electrophysiological activity, 2) that electrical stimulation in the medial forebrain bundle (MFB) region resulted in electrochemically-transduced dopamine transients in the striatum that were spatially heterogeneous within at least 200 µm, and 3) following MFB stimulation, dopamine levels and electrophysiological activity within the striatum exhibited similar temporal profiles. These neural probes are capable of incorporating customized microelectrode geometries and configurations, which may be useful for examining specific spatiotemporal relationships between electrical and chemical signaling in the brain.

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A new probe to monitor the effects of drugs on local field potentials

Cited by 10 publications

References 16 publications

Disinhibition reduces extracellular glutamine and elevates extracellular glutamate in rat hippocampus in vivo

Disinhibition reduces extracellular glutamine and elevates extracellular glutamate in rat hippocampus in vivo

Non-Linear Dynamics in Parkinsonism

Implantable microelectrode arrays for simultaneous electrophysiological and neurochemical recordings

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