SiNAPS Pixel Probes

SiNAPS is capable of creating a map that represents neural activity not only in a small portion of the brain but also across wide areas of the brain.

Presented below are images showcasing acute recordings obtained from a single- and 4-shank SiNAPS probe that was implanted in an anesthetized rodent.

Displayed at the top is an example of in vivo neural activity recordings obtained through a SiNAPS probe implanted in the brain of an anesthetized rat, with the probe’s location specified in the top-left inset. The curves signify the full-band bioelectrical signals recorded from the somatosensory cortex to the hippocampus for a time period of 7 seconds. A total of 320 electrodes were employed to record physiologically-related signals, with only a subset of 110 electrodes (pitch of 28 µm) displayed to avoid overwhelming the visualization. The bottom panel presents a detailed view of a single raw neural trace recorded in the hippocampus, both in its original form and after being filtered offline in the LFP (1–300 Hz) and AP (300–5000 Hz) frequency bands. Further details can be found by following this link.

In vivo recordings were conducted with a multi-shank SiNAPS probe. A. For each shank, a representative subset of 100 ms of broadband neural signals from the available 1024 channels was collected and displayed. B. A raster plot of single unit activity (n = 219) recorded from the entire probe was presented, with each color indicating the macrostructure from which a specific neuron was obtained. C. Additionally, an example of bandpass filtered (300-5000 Hz) neural data collected from a portion of one of the shanks (red area composed of 108 neighboring consecutive channels) of the probe depicted in (A) was shown, along with the waveforms of a subset of units recorded from those channels on the right side of the image. Further details can be found by following this link.

The images below depict the optogenetic single-unit and LFP light-evoked responses recorded from 4-shnak SiNAPS probe.

The above image display single-unit light-evoked responses using a 4-shank probe. A. Representation of the probe features spike waveforms of the isolated single-unit responses, with colored dots indicating the location of single units on the probe. B. Examples of the spike rasters and peri-stimulus histograms are shown for optogenetic stimulation of six isolated single units, with the color coding indicating the relative position of the isolated single units on the probe. Light-blue rectangles indicate the period in which the optostimulation is on.

The image above shows the optogenetic LFP light-evoked responses. A. 4-shank probe was positioned and superimposed onto an approximate mouse atlas coronal section (Allen Mouse Brain Atlas). Representative 50ms portions of LFP responses collected along the probe shanks after the light stimulus onset are shown in black curves. A false-color map represents the interpolated peak-to-peak values of the low-frequency responses over the probe’s two-dimensional plane, with the estimated fiber tip position projected on the probe’s coronal plane highlighted by a blue circle. B. Example of the broadband signals recorded from five neighboring channels sampled from the four different shanks is presented, with the blue rectangle indicating light stimulation and the yellow rectangle showing the time used to generate the false-color map. Further details can be found by following this link.

References:

• An implantable active pixel sensor CMOS-probe for simultaneous large-scale neural recordings. Angotzi GN, et al., Biosens Bioelectron (2019): 126:355-364. doi: 10.1016/j.bios.2018.10.032.
• Multi-shanks SiNAPs active pixel sensor CMOS probe: 1024 simultaneously recording channels for high-density intracortical brain mapping. Boi F., et al., bioRxiv (2019): doi: https://doi.org/10.1101/749911.
• Coupling SiNAPS High-density Neural Recording CMOS-Probes with Optogenetic Light Stimulation. Boi F., et al., IEEE Biomedical Circuits and Systems Conference (BioCAS) (2021): 1-4, doi: 10.1109/BioCAS49922.2021.9645041.
• Bioelectrodes for high-channel count and small form factor CMOS neural probes. Ribeiro J.F., et al., IEEE EMBS Conference on Neural Engineering (NER) (2021): 388-391, doi: 10.1109/NER49283.2021.9441160.
• Channels, Layout and Size Scalability of Implantable CMOS-Based Multielectrode Array Probes, Ribeiro J.F., et al., IEEE International Electron Devices Meeting (IEDM) (2022): 29.6.1-29.6.4, doi: 10.1109/IEDM45625.2022.10019384.

Available Options:

Electrodes: 256 & 1024 recording sites

• SiNAPS_1S_256 : 1-shank probe with 256 recording sites
• SiNAPS_4S_1024: 4-shank probe with 1024 recording sites (256 recording sites/shank)

System Requirements

• Smartbox Pro
• Activus SiNAPS interface box
• Radiens Analytics Suite
• Laptop or desktop computer

Check SiNAPS Knowledge Base for a brief overview of the SiNAPS system operation and SiNAPS electrode calibration.

Guideline for cleaning explanted SiNAPS probe

This image provides an example of in vivo neural activity recording using a SiNAPS probe. A) The architecture features a single shank with 256 SiNAPS probes implanted into the mouse brain. B) An averaged spike waveform from each individual site is shown as an example. C) A subset of 32 sites is shown in a close-up view that has been off-line filtered in the local field potential (LFP) frequency band (1-300 Hz). D) The raster time series of all sites off-line filtered in the action potential (AP) frequency band (300-5000 Hz) are displayed.