New Trends and Challenges in the Development of Microfabricated Probes for Recording and Stimulating of Excitable Cells

Abstract

types of neural prostheses are unclear. Notable exceptions for this are the auditory cochlear prostheses, which exploit the sonotopic organization of the cochlea, the cardiac pacemakers, the phrenic stimulator and the foot drop stimulator. Current DBS systems for Parkinson's disease rely on the high frequency stimulation, which can result in blocking of certain mid-brain pathways. The encoding of the kinematic information in these structures is still unknown. Dissociated cell cultures lose their anatomical connectivity and structure when seeded on substrates in vitro. The 'new' situation that exists on these surfaces is interesting in terms of communication between individual cells and their function in advanced networks. However, the translation of these processes to the in vivo situation is not always straightforward and challenging. On the level of the overall device several types of issues can be grouped in the categories of configuration and operation. Issues related to the configuration can be related to the assembly, the size and topology of the device, the encapsulation and the packaging of the device. Devices have to be packaged in a way that prevents leakage of the environment, which contains high salt and protein concentrations, to the chip. These packages have to be leakage-proof on the one hand and non-toxic for the cell culture or tissue on the other hand. Issues related to the operation of the device can be grouped under the power, safety and communication of the device. The operation has to be compatible with cell cultures or in vivo environments, which in this case has to be in agreement with certain regulations. One other important aspect of the safety of operation are the interactions with other equipment, for example MRI.

Mechanism behind the neuronal ephaptic coupling during synchronizing by specific brain-triggered wave as neuronal motor toolkit

“…This was adopted for culturing in the micro-channels via adjusting the angle and position of the micro-electrode system. www.nature.com/scientificreports/ The gigaseal condition was provided based on a reported procedure 22 , briefly, via blind controlling the forward and backward positions of the micro-electrodes linearly using the stepper motor, implanted on the snail's neuron cell and differentiation NSCs, along with direct measuring the electrical resistance by using an ohmmeter (Digital Multimeter, Fluke 115 True RMS, US). At this ohmic condition, obviously, besides the faraday's cage, and neuronal condition at 6.42 ± 0.72 GΩ/cm (n = 5) for the cell recognition resistivity, we should filtered most of external random perturbations during the direct potentiometry for sensing the AP using the two micro-electrode systems.…”

In Vivo Chemogenetic Biocompatibility of Mercury as a Specific Hypercalcemia Actuator in Snail’s Spinal Cord Cell Manipulation: An Extracellular Field Potential Biosensor

“…17 The giga ohm sealed condition was also developed based on a previously reported procedure. 18 Briefly, this was achieved via linearly (forward and backward) moving the implanted microelectrodes with hands and/or using the stepper motors, along with directly measuring the electrical resistance by a digital ohmmeter (Digital Multimeter, Fluke 115 True RMS). This giga ohm sealed condition (i.e., 6.42 ± 0.72 GΩ cm, n = 5) majorly filtered most of the external random perturbations (noises) during direct potentiometric sensing of the action potential (AP) using the implanted microelectrode system.…”

“…The giga ohm sealed condition was also developed based on a previously reported procedure . Briefly, this was achieved via linearly (forward and backward) moving the implanted microelectrodes with hands and/or using the stepper motors, along with directly measuring the electrical resistance by a digital ohmmeter (Digital Multimeter, Fluke 115 True RMS).…”

Automated Segmentation and Morphometry of Cell and Tissue Structures. Selected Algorithms in ImageJ

“…Proposed approach can be used to investigate the factors which contribute to the loss of signal in chronic microelectrode recordings. From the side of the brain this phenomenon can be caused by (i) spatial shift caused by the formation of the glial scar, (ii) neuronal cell death around the implanted probe or (iii) silencing of the surrounding neurons (review in Braeken & Prodanov (2010)). Activation of microglial cells results in a substantial increase in their phagocytic capacity.…”