Microchip amplifier for in vitro, in vivo, and automated whole cell patch-clamp recording

Abstract

Patch clamping is a gold-standard electrophysiology technique that has the temporal resolution and signal-to-noise ratio capable of reporting single ion channel currents, as well as electrical activity of excitable single cells. Despite its usefulness and decades of development, the amplifiers required for patch clamping are expensive and bulky. This has limited the scalability and throughput of patch clamping for single-ion channel and single-cell analyses. In this work, we have developed a custom patch-clamp amplifier microchip that can be fabricated using standard commercial silicon processes capable of performing both voltage- and current-clamp measurements. A key innovation is the use of nonlinear feedback elements in the voltage-clamp amplifier circuit to convert measured currents into logarithmically encoded voltages, thereby eliminating the need for large high-valued resistors, a factor that has limited previous attempts at integration. Benchtop characterization of the chip shows low levels of current noise [1.1 pA root mean square (rms) over 5 kHz] during voltage-clamp measurements and low levels of voltage noise (8.2 μV rms over 10 kHz) during current-clamp measurements. We demonstrate the ability of the chip to perform both current- and voltage-clamp measurement in vitro in HEK293FT cells and cultured neurons. We also demonstrate its ability to perform in vivo recordings as part of a robotic patch-clamping system. The performance of the patch-clamp amplifier microchip compares favorably with much larger commercial instrumentation, enabling benchtop commoditization, miniaturization, and scalable patch-clamp instrumentation.

Assembly and operation of the autopatcher for automated intracellular neural recording in vivo

“…9h). Coupling of other devices to the autopatcher setup 32 may enable the integration of the autopatcher into experiments involving extracellular recording, pharmacological infusion and other neuroscience strategies of importance. As a final note, the protocol described above has been tried and tested in anesthetized mice.…”

In vitro comparative analysis of human dental stem cells from a single donor and its neuronal differentiation potential evaluated by electrophysiology

“…These gated channels in case of neurons are Ca + , Na + and K + channels [40]. Whole cell patch clamping technique that is a gold standard of reporting single ion channel currents [41] was used to record Na + and K + current in DF and NDF dental MSCs. We found only voltage-gated functional Na + channel in DF cells, which were completely absent in NDF cells.…”

3D Image-Guided Automatic Pipette Positioning for Single Cell Experiments in vivo

“…Additionally, when the time for image collection is considered, the time required for our method is comparable to a human operator, generating image data and experimental parameters such as pipette and target position available for on-line and post-hoc analysis. Image-guided adaptive pipette movement may also be a useful addition for automated and semi-automated electrophysiology in vitro 7 8 15 16 . In future studies, our principal method of using adaptive pipette movement could be applied to more challenging experimental paradigms, such as fine-tuning the pipette position and completing electrophysiological recordings or compensating for movement of targeted neurons in awake, behaving animals.…”