PMID-12904510[0] Csicsvari 2003 Massively parallel recording of unit and local field potentials with silicon-based electrodes
- What's so massive? 64 or 96 channel Michigan probes.
- Motivation: recording local connections and interactions requires precise knoledge of the location of your recording sites.
- Some classic refs on cortical building blocks.
- Optical recording: Mao et al 2001 PMID-11738033.
- Wired recording:, Chicurel 2001; Deadwyler and Hampson 1995 PMID-7481817; Evarts 1968; {994}
- Tetrodes: Drake 1988, Gray 1995, McNaughton et al 1983; Recce and O'Keefe 1989.
- on-chip active circuitry (simple voltage feedback op-amp - without reference electrodes!) reduces microphone artifact. 6mm 'antenna'.
- refs: Bai and Wise 2001 {995}; Olsson et al. 2002
- also Najafi and Wise 1986 {996}; Wise and Najafi 1991 .
- Stored wideband data; sorted via KlustaKwik.
- Total recording area 1.6mm deep by 1.8mm wide. Shanks separated by 300um ; recordings sites separated by 100um; shanks 12um thick.
- Made via double-sided deep reactive reactive ion etching (DRIE).
- stimulated the entorhinal cortex & recorded in the hippocampus; used the precise spatial layout of the micromachined silicon electrodes to map out the evoked potentials.
- figure 3 shows that they can record the 'same' neuron from multiple 100um-spaced sites on a given shank. Some of this is due to the physically large extent of the hippocampal cells which they recorded; spike propagate both down the axon and back into the soma, and by using Current Source Density maps, they could estimate some of spatio-temporal characterisics of the AP.
- CSD is the second spatial derivtive of the local field potentials.
- Could measure forward and back-propagation of APs to the dendrites (!)
- quote: in contrast to wire tetrodes with blunt cute ends, it was possible to record from the same cell layer numerous times after moving the probe up and subsequently back to the previous recording location.
- size of the electrode shanks: 62um wide x 12um thick at top of recording site of 12 site shank; 82um wide at top of 16 site shank.
- Top 4 recording sites' recording quality deteriorated with multiple penetrations.
- good place-cell map; cells were discriminated based on a PCA across both time and electrode.
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