1,721,100 research outputs found
In Vitro Neuronal Network-on-a-Chip Technology—From Millimeter to Centimeter-Scale Networks
No full textBrain-on-a-Chip technology: Application of thermo-plasmonics to control neural activity on a chip
No full textA 3D neuronal network read-out interface with high recording performance using a neuronal cluster patterning on a microelectrode array
No full textIn recent years, in vitro three-dimensional (3D) neuronal network models utilizing extracellular matrices have been advancing. To understand the network activity from these models, attempts have been made to measure activity in multiple regions simultaneously using a microelectrode array (MEA). Although there hve been many attempts to measure the activity of 3D networks using 2-dimensional (2D) MEAs, the physical coupling between the 3D network and the microelectrodes was not stable and needed to be improved. In this study, we proposed a neuronal cluster interface that improves the active channel ratio of commercial 2D MEAs, enabling reliable measurement of 3D network activity. To achieve this, neuronal clusters, which consist of a small number of neurons, were patterned on microelectrodes and used as mediators to transmit the signal between the 3D network and the microelectrodes. We confirmed that the patterned neuronal clusters enhanced the active channel ratio and SNR(signal-to-noise-ratio) about 3D network recording and stimulation for a month. Our interface was able to functionally connect with 3D networks and measure the 3D network activity without significant alternation of activity characteristics. Finally, we demonstrated that our interface can be used to analyze the differences in the dynamics of 3D and 2D networks and to construct the 3D clustered network. This method is expected to be useful for studying the functional activity of various 3D neuronal network models, offering broad applications for the use of these models.
Micropatterning Using Thermoplasmonic Interface and Hydrogel for IN SITU Manipulation of Neuronal Networks
No full textOptical Recording of Neural response in Cultured Neurons during Gold-nanorod Mediated Photothermal Inhibition
No full textSimultaneous Optical and Electrical Measurements of Neural Activities from Clustered Neural Networks
No full textBin-size scanning and plateau search method for criticality analysis of neuronal network activity
No full textPolydopamine-doped conductive polymer microelectrodes for neural recording and stimulation
No full textBackground: Microelectrodes have been widely used to detect and modulate the activities of neuronal networks. Various materials have been applied to microelectrode fabrication, and the conductive polymer is one of the most intensively explored material. The properties of conductive polymer highly depend on the incorporated material, so selecting it is essential. The mussel-inspired biomolecule, polydopamine (pDA), is known to provide unique chemical and mechanical properties to biological interfaces. New Method: pDA was incorporated into poly(3,4-ethylenedioxythiophene) (PEDOT) resulting in polydopamine PEDOT hybrid (PEDOT/pDA) microelectrode by an electrochemical deposition method. The electrical properties, such as impedance, charge storage capacity (CSC), and charge injection limit (CIL), of PEDOT/pDA microelectrodes, were characterized. Results: PEDOT/pDA microelectrodes had low impedance, high CSC, and high CIL, which are prerequisite for neuronal signal recording and stimulation. Then, neuronal recordings and electrical stimulations were conducted to verify the functionality of the PEDOT/pDA microelectrodes. Spontaneous and evoked extracellular neuronal signals were successfully measured from cultured rat hippocampal neuronal networks, and the recorded signals showed excellent signal-to-noise ratio for the detection of extracellular spikes. Comparison with Existing Methods: Compared with existing conductive polymer based neural electrodes, the PEDOT/pDA microelectrode had chemically functional material, pDA, embedded in the electrode, while it had comparable level of impedance and CSC and CIL for neural stimulation and recordings. Conclusions: We have shown that it is possible to fabricate a microelectrode array of pDA doped PEDOT microelectrodes and validated its performance for neuronal signal recording and electrical stimulation. The PEDOT/pDA microelectrode with excellent electrical performance and biocompatibility will be a promising tool for studying neuronal networks.
Optical recording of neural responses to gold-nanorod mediated photothermal neural inhibition
No full textBackground
Photothermal stimulation is a heat-mediated neuromodulation technique. When photothermal effects are induced on neuronal membrane, it can either excite or inhibit neural spiking activities. It has been demonstrated that gold nanorod mediated photothermal stimulation could decrease the electrical activity of cultured neural network. We investigated the effect of photothermal inhibition on neural activity using calcium imaging technique.
New method
Hippocampal neurons were cultured on a gold-nanorod-coated-microelectrode array and near-infrared laser was illuminated to induce neural inhibition. The neuronal responses at a single-cell resolution were measured by an extracellular recording and calcium imaging simultaneously.
Results
The photothermal effect on neural spikes were confirmed by electrical recording and calcium imaging. The decrease in neural spikes in electrical recordings during NIR illumination was correlated with the neighboring neural activity quantified by calcium spikes.
Comparison with existing method(s)
Optical recording at the single cell resolution was attempted during photothermal stimulation to confirm the neural suppression effect.
Conclusions
Heat mediated suppression of neural activity was optically validated in single cell level. The present study will be helpful to understand the emerging photothermal neuromodulation technology
Fabrication of Polydopamine Doped Conductive Polymer Microelectrode for Neural Recording
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