Nano-ampere stimulation window for cultured neurons on micro-electrode arrays

AbstractThe quality of bioelectrical signals is essential for functional evaluation of cellular circuits. The electrical activity recorded from the cortical brain surface represents the average of many individual synaptic processes. By downsizing micro-electrode arrays, the spatial resolution of electrocortico-grams (ECoGs) can be increased. But, upon increasing electrode impedance, recorded noise from the electrode-tissue interface and the surroundings will become more prominent. Frequently, signal interpretation is improved by post-processing using filtering or pattern recognition. For a variety of applications, wavelet denoising has become an accepted tool. Here, we present how wavelet denoising affects the signal-to-noise ratio of ECoGs. The recording qualities from awake and anesthetized mice was artificially reduced by adding two noise models prior to filtering. Raw and filtered signals were compared by calculating the linear correlation coefficient.

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Deuterated Glutamate-Mediated Neuronal Activity on Micro-Electrode Arrays

Micromachines ◽

10.3390/mi11090830 ◽

2020 ◽

Vol 11 (9) ◽

pp. 830

Author(s):

Wataru Minoshima ◽

Kyoko Masui ◽

Tomomi Tani ◽

Yasunori Nawa ◽

Satoshi Fujita ◽

...

Keyword(s):

Spontaneous Activity ◽

Neuronal Activity ◽

Hippocampal Neurons ◽

Neuronal Networks ◽

Microelectrode Array ◽

Mammalian Brain ◽

Electrode Arrays ◽

Physiological Properties ◽

Micro Electrode Arrays

The excitatory synaptic transmission is mediated by glutamate (GLU) in neuronal networks of the mammalian brain. In addition to the synaptic GLU, extra-synaptic GLU is known to modulate the neuronal activity. In neuronal networks, GLU uptake is an important role of neurons and glial cells for lowering the concentration of extracellular GLU and to avoid the excitotoxicity. Monitoring the spatial distribution of intracellular GLU is important to study the uptake of GLU, but the approach has been hampered by the absence of appropriate GLU analogs that report the localization of GLU. Deuterium-labeled glutamate (GLU-D) is a promising tracer for monitoring the intracellular concentration of glutamate, but physiological properties of GLU-D have not been studied. Here we study the effects of extracellular GLU-D for the neuronal activity by using primary cultured rat hippocampal neurons that form neuronal networks on microelectrode array. The frequency of firing in the spontaneous activity of neurons increased with the increasing concentration of extracellular GLU-D. The frequency of synchronized burst activity in neurons increased similarly as we observed in the spontaneous activity. These changes of the neuronal activity with extracellular GLU-D were suppressed by antagonists of glutamate receptors. These results suggest that GLU-D can be used as an analog of GLU with equivalent effects for facilitating the neuronal activity. We anticipate GLU-D developing as a promising analog of GLU for studying the dynamics of glutamate during neuronal activity.

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Architecture, Fabrication, and Properties of Stretchable Micro-Electrode Arrays

IEEE Sensors, 2005. ◽

10.1109/icsens.2005.1597913 ◽

2006 ◽

Cited By ~ 3

Author(s):

C. Tsay ◽

S.P. Lacour ◽

S. Wagner ◽

B. Morrison

Keyword(s):

Electrode Arrays ◽

Micro Electrode Arrays

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Graphene-based carbon-layered electrode array technology for neural imaging and optogenetic applications

Nature Communications ◽

10.1038/ncomms6258 ◽

2014 ◽

Vol 5 (1) ◽

Cited By ~ 286

Author(s):

Dong-Wook Park ◽

Amelia A. Schendel ◽

Solomon Mikael ◽

Sarah K. Brodnick ◽

Thomas J. Richner ◽

...

Keyword(s):

Soft Tissues ◽

Electrode Array ◽

Electrode Arrays ◽

Neural Imaging ◽

Brain Surface ◽

Array Technology ◽

Micro Electrode Arrays ◽

The Brain

Abstract Neural micro-electrode arrays that are transparent over a broad wavelength spectrum from ultraviolet to infrared could allow for simultaneous electrophysiology and optical imaging, as well as optogenetic modulation of the underlying brain tissue. The long-term biocompatibility and reliability of neural micro-electrodes also require their mechanical flexibility and compliance with soft tissues. Here we present a graphene-based, carbon-layered electrode array (CLEAR) device, which can be implanted on the brain surface in rodents for high-resolution neurophysiological recording. We characterize optical transparency of the device at >90% transmission over the ultraviolet to infrared spectrum and demonstrate its utility through optical interface experiments that use this broad spectrum transparency. These include optogenetic activation of focal cortical areas directly beneath electrodes, in vivo imaging of the cortical vasculature via fluorescence microscopy and 3D optical coherence tomography. This study demonstrates an array of interfacing abilities of the CLEAR device and its utility for neural applications.

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