PMID-22905231 Neuronal recordings with solid-conductor intracellular nanoelectrodes (SCINEs).
- <300 nm diameter W fibers, several um long, fabricated via FIB.
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- Functionalized with a hydrophobic silane on the oxide.
- Quite complete & custom methods here.
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- Not quite whole cell recording, but excellent SNR; 4mv APs.
- Slice, rat hippocampus organotypic.
- Expected much larger recorded APs; suspect partial membrane penetration.
- Only lasted a few seconds to minutes.
- Needed custom recording setup for interfacing with 100Gohm electrodes; stray capacitance < 4 pf.
- Intracellular electrodes must be designed to not shunt the membrane open upon insertion.
- In a study where whole-cell recordings were established prior sharp microelectrode penetration, all neurons showed significant depolarization following impalement.
- Here there was no change in membrane voltage in 10% of insertions of the silane-functionalized SCINEs. only in the functionalized electrodes).
- Minor distortion of the AP was observed.
- In whole-cell patch clamping, diffusion from the pipette to the cytosol interrupts biochemical processes necessary for normal cellular function (e.g. respiration!).
- The hardness of the tungsten ensures that SCINEs can be repeatedly inserted millimeter-deep into brain tissue without noticeable damage to the tip.
- E.g. 300 nm tungsten will not easily navigate vasculature...
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