Recording High Frequency Neural Signals Using Conformable and Low-Impedance ECoG Electrodes Arrays Coated with PEDOT-PSS-PEG

2016 ◽  
Vol 102 ◽  
pp. 77-85 ◽  
Author(s):  
Elisa Castagnola ◽  
Marco Marrani ◽  
Emma Maggiolini ◽  
Francesco Maita ◽  
Luca Pazzini ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
High Frequency ◽  
Cortical Neurons ◽  
Ad Hoc ◽  
Ionic Conductivities ◽  
Neural Signals ◽  
Brain Surface ◽  
Small Neuron ◽  
Rat Somatosensory Cortex

Electrocorticography (ECoG) is receiving growing attention for both clinical and research applications thanks to its reduced invasiveness and ability of addressing large cortical areas. These benefits come with a main drawback, i.e. a limited frequency bandwidth. However, recent studies have shown that spiking activity from cortical neurons can be recorded when the ECoG grids present the following combined properties: (I) conformable substrate, (II) small neuron-sized electrodes with (III) low-impedance interfaces. We introduce here an ad-hoc designed ECoG device for investigating how electrode size, interface material composition and electrochemical properties affect the capability to record evoked and spontaneous neural signals from the rat somatosensory cortex and influence the ability to record high frequency neural signal components.Contact diameter reduction down to 8 μm was possible thanks to a specific coating of a (3,4-ethylenedioxytiophene)-poly (styrenesulfonate)-poly-(ethyleneglycol) (PEDOT-PSS-PEG) composite that drastically reduces impedance and increases electrical and ionic conductivities. In addition, the extreme thinness of the polyimide substrate (6 - 8 μm) and the presence of multiple perforations through the device ensure an effective contact with the brain surface and the free flow of cerebrospinal fluid. In-vivo validation was performed on rat somatosensory cortex.

scholarly journals Smoothened receptor signaling regulates the developmental shift of GABA polarity in rat somatosensory cortex

2020 ◽  
Vol 133 (20) ◽  
pp. jcs247700
Author(s):  
Quentin Delmotte ◽  
Mira Hamze ◽  
Igor Medina ◽  
Emmanuelle Buhler ◽  
Jinwei Zhang ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Cortical Neurons ◽  
Functional Expression ◽  
Brain Maturation ◽  
Surface Stability ◽  
Chloride Homeostasis ◽  
Cell Proliferation And Differentiation ◽  
Developmental Shift ◽  
Proliferation And Differentiation ◽  
Rat Somatosensory Cortex

ABSTRACTSonic hedgehog (Shh) and its patched–smoothened receptor complex control a variety of functions in the developing central nervous system, such as neural cell proliferation and differentiation. Recently, Shh signaling components have been found to be expressed at the synaptic level in the postnatal brain, suggesting a potential role in the regulation of synaptic transmission. Using in utero electroporation of constitutively active and negative-phenotype forms of the Shh signal transducer smoothened (Smo), we studied the role of Smo signaling in the development and maturation of GABAergic transmission in the somatosensory cortex. Our results show that enhancing Smo activity during development accelerates the shift from depolarizing to hyperpolarizing GABA in a manner dependent on functional expression of potassium–chloride cotransporter type 2 (KCC2, also known as SLC12A5). On the other hand, blocking Smo activity maintains the GABA response in a depolarizing state in mature cortical neurons, resulting in altered chloride homeostasis and increased seizure susceptibility. This study reveals unexpected functions of Smo signaling in the regulation of chloride homeostasis, through control of KCC2 cell-surface stability, and the timing of the GABA excitatory-to-inhibitory shift in brain maturation.

Characteristic Membrane Potential Trajectories in Primate Sensorimotor Cortex Neurons Recorded In Vivo

2005 ◽  
Vol 94 (4) ◽  
pp. 2713-2725 ◽  
Author(s):  
Daofen Chen ◽  
Eberhard E. Fetz
Keyword(s):  
Membrane Potential ◽  
Sensorimotor Cortex ◽  
High Frequency ◽  
Cortical Neurons ◽  
Type I ◽  
Type Ii ◽  
Interspike Intervals ◽  
Cortical Oscillations ◽  
Firing Properties

We examined the membrane potentials and firing properties of motor cortical neurons recorded intracellularly in awake, behaving primates. Three classes of neuron were distinguished by 1) the width of their spikes, 2) the shape of the afterhyperpolarization (AHP), and 3) the distribution of interspike intervals. Type I neurons had wide spikes, exhibited scoop-shaped AHPs, and fired irregularly. Type II neurons had narrower spikes, showed brief postspike afterdepolarizations before the AHP, and sometimes fired high-frequency doublets. Type III neurons had the narrowest spikes, showed a distinct post-AHP depolarization, or “rebound AHP” (rAHP), lasting nearly 30 ms, and tended to fire at 25–35 Hz. The evidence suggests that an intrinsic rAHP may confer on these neurons a tendency to fire at a preferred frequency governed by the duration of the rAHP and may contribute to a “pacemaking” role in generating cortical oscillations.

Effects of Ventrobasal Lesion and Cortical Cooling on Fast Oscillations (>200 Hz) in Rat Somatosensory Cortex

2003 ◽  
Vol 89 (5) ◽  
pp. 2380-2388 ◽  
Author(s):  
Richard J. Staba ◽  
Barbara Brett-Green ◽  
Marcy Paulsen ◽  
Daniel S. Barth
Keyword(s):  
Somatosensory Cortex ◽  
Oscillatory Activity ◽  
Electrode Arrays ◽  
Subcortical Structures ◽  
Ventrobasal Thalamus ◽  
Before And After ◽  
Cortical Cooling ◽  
Rat Somatosensory Cortex ◽  
Fast Oscillations

High-frequency oscillatory activity (>200 Hz) termed “fast oscillations” (FO) have been recorded in the rodent somatosensory cortex and may reflect very rapid integration of vibrissal information in sensory cortex. Yet, while electrophysiological correlates suggest that FO is generated within intracortical networks, contributions of subcortical structures along the trigeminal pathway remain uncertain. Using surface and laminar electrode arrays, in vivo recordings of vibrissal and electrically evoked FO were made within somatosensory cortex of anesthetized rodents before and after ablation of the ventrobasal thalamus (VB) or during reversible cortical cooling. In VB-lesioned animals, vibrissal stimulation failed to evoke FO, while epicortical stimulation in lesioned animals remained effective in generating FO. In nonlesioned animals, cortical cooling eliminated vibrissal-evoked FO despite the persistence of thalamocortical input. Vibrissal-evoked FO returned with the return to physiological temperatures. Results from this study indicate that somatosensory cortex alone is able to initiate and sustain FO. Moreover, these data suggest that cortical network interactions are solely responsible for the generation of FO, while synchronized thalamocortical input serves as the afferent trigger.

Intracellular Correlates of Fast (>200 Hz) Electrical Oscillations in Rat Somatosensory Cortex

2000 ◽  
Vol 84 (3) ◽  
pp. 1505-1518 ◽  
Author(s):  
Michael S. Jones ◽  
Kurt D. MacDonald ◽  
ByungJu Choi ◽  
F. Edward Dudek ◽  
Daniel S. Barth
Keyword(s):  
Action Potential ◽  
Somatosensory Cortex ◽  
Field Potential ◽  
Oscillatory Activity ◽  
Cellular Events ◽  
Recurrent Activity ◽  
Potential Recording ◽  
Rat Somatosensory Cortex ◽  
Fast Oscillations

Oscillatory activity in excess of several hundred hertz has been observed in somatosensory evoked potentials (SEP) recorded in both humans and animals and is attracting increasing interest regarding its role in brain function. Currently, however, little is known about the cellular events underlying these oscillations. The present study employed simultaneous in-vivo intracellular and epipial field-potential recording to investigate the cellular correlates of fast oscillations in rat somatosensory cortex evoked by vibrissa stimulation. Two distinct types of fast oscillations were observed, here termed “fast oscillations” (FO) (200–400 Hz) and “very fast oscillations” (VFO) (400–600 Hz). FO coincided with the earliest slow-wave components of the SEP whereas VFO typically were later and of smaller amplitude. Regular spiking (RS) cells exhibited vibrissa-evoked responses associated with one or both types of fast oscillations and consisted of combinations of spike and/or subthreshold events that, when superimposed across trials, clustered at latencies separated by successive cycles of FO or VFO activity, or a combination of both. Fast spiking (FS) cells responded to vibrissae stimulation with bursts of action potentials that closely approximated the periodicity of the surface VFO. No cells were encountered that produced action potential bursts related to FO activity in an analogous fashion. We propose that fast oscillations define preferred latencies for action potential generation in cortical RS cells, with VFO generated by inhibitory interneurons and FO reflecting both sequential and recurrent activity of stations in the cortical lamina.

Time-Dependent, Layer-Specific Modulation of Sensory Responses Mediated by Neocortical Layer 1

2006 ◽  
Vol 96 (6) ◽  
pp. 3170-3182 ◽  
Author(s):  
Dan Shlosberg ◽  
Yael Amitai ◽  
Rony Azouz
Keyword(s):  
Somatosensory Cortex ◽  
Cortical Neurons ◽  
Sensory Information ◽  
Time Dependent ◽  
Inhibitory Influence ◽  
Sensory Responses ◽  
Specific Regulation ◽  
Sensory Evoked

An essential component of feedback and top-down information in the cortical column arrives at layer 1 (L1) where it contacts distal dendrites of pyramidal neurons. Although much is known about the anatomical organization of L1 fibers, their contribution to sensory information processing remains to be determined. We assessed the physiological significance of L1 inputs by performing extracellular recordings in vivo from neurons in the primary somatosensory cortex of rodents. We found that blocking activity in L1 increases whisker-evoked response magnitude and variance, suggesting that L1 exerts an inhibitory influence on whisker responses. However, when pairing L1 stimulation with whisker deflection, the interval between the stimuli determined the outcome of the interaction, with facilitation of sensory responses dominating the short intervals (≤10 ms) and suppression prevailing at longer intervals (>10 ms). These temporal interactions resulted in a time-dependent regulation of direction tuning of cortical neurons. The synaptic mechanisms underlying L1 inputs’ influences were examined using whole cell recordings in vitro while pairing L1 and white-matter stimulations. We found time-dependent, layer-specific differences in synaptic summation of the two inputs, with supralinearity at shorter intervals and sublinearity at longer intervals that resulted mainly from shunting inhibition. Taken together, our results demonstrate that L1 inputs impose a time- and layer-specific regulation on sensory-evoked responses. This in turn may lead to a dynamic transmission of sensory information in the somatosensory cortex.

scholarly journals Pulsed infrared light alters neural activity in rat somatosensory cortex in vivo

NeuroImage ◽  
2011 ◽  
Vol 57 (1) ◽  
pp. 155-166 ◽  
Author(s):  
Jonathan M. Cayce ◽  
Robert M. Friedman ◽  
E. Duco Jansen ◽  
Anita Mahavaden-Jansen ◽  
Anna W. Roe
Keyword(s):  
Somatosensory Cortex ◽  
Neural Activity ◽  
Infrared Light ◽  
Rat Somatosensory Cortex

scholarly journals Development of optically controlled “living electrodes” with long-projecting axon tracts for a synaptic brain-machine interface

2021 ◽  
Vol 7 (4) ◽  
pp. eaay5347
Author(s):  
Dayo O. Adewole ◽  
Laura A. Struzyna ◽  
Justin C. Burrell ◽  
James P. Harris ◽  
Ashley D. Nemes ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Brain Activity ◽  
Optical Recording ◽  
New Class ◽  
Brain Surface ◽  
Machine Interface ◽  
The Brain

For implantable neural interfaces, functional/clinical outcomes are challenged by limitations in specificity and stability of inorganic microelectrodes. A biological intermediary between microelectrical devices and the brain may improve specificity and longevity through (i) natural synaptic integration with deep neural circuitry, (ii) accessibility on the brain surface, and (iii) optogenetic manipulation for targeted, light-based readout/control. Accordingly, we have developed implantable “living electrodes,” living cortical neurons, and axonal tracts protected within soft hydrogel cylinders, for optobiological monitoring/modulation of brain activity. Here, we demonstrate fabrication, rapid axonal outgrowth, reproducible cytoarchitecture, and simultaneous optical stimulation and recording of these tissue engineered constructs in vitro. We also present their transplantation, survival, integration, and optical recording in rat cortex as an in vivo proof of concept for this neural interface paradigm. The creation and characterization of these functional, optically controllable living electrodes are critical steps in developing a new class of optobiological tools for neural interfacing.

scholarly journals Direct Activation of Cortical Neurons in the Primary Somatosensory Cortex of the Rat in Vivo Using Focused Ultrasound

2020 ◽  
Vol 46 (9) ◽  
pp. 2349-2360
Author(s):  
Kush Tripathi ◽  
Tongsheng Zhang ◽  
Nathan McDannold ◽  
Yong-Zhi Zhang ◽  
Gösta Ehnholm ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Cortical Neurons ◽  
Focused Ultrasound ◽  
Primary Somatosensory Cortex ◽  
Direct Activation
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