SiNAPS Pixel Probes

SfN/AES SiNAPS Posters:

• Chronic SiNAPS implants: A SiNAPS research platform for behavioral studies with implantable CMOS probes 
  Poster Number: RR10
• SiNAPS probes and data: Performances of active CMOS-based SiNAPS neural probes up to 1024 simultaneously recording electrode channels.
  Poster Number: VV63
• SiNAPS implantation: Strategies for improving the chronic in-vivo integration of SiNAPS neural probes and assessment of performances
  Poster Number: WW10
• Research poster: Synaptic endocannabinoid signaling modulates the reciprocal functional connectivity between the prefrontal cortex and the noradrenergic locus coeruleus
  Poster Number: KK4
• Research poster: Defining Features of Human Hippocampal Sharp-Wave Ripples and Interictal Epileptiform Discharges: Insights from High-density Recordings in Rodents
  Poster Number: 3.483

Below is a recording obtained from a Radiens Allego of a head-fixed (awake) mouse using a SiNAPS four-shank probe with 1024 simultaneously recorded channels.

During the week of May 1st, a small team of NeuroNexus engineers and scientists visited a top systems neuroscience lab in New York to initiate a collaborative study using our new SiNAPS Pixel probes to investigate neural circuit dynamics with unprecedented spatiotemporal resolution.  While this study is ongoing, we’re pleased to highlight some early findings:

1. Methods: Over 3.5 days, full-band recordings (spikes and LFPs) were obtained from anesthetized and awake, head-fixed mice using the fully-integrated NeuroNexus Smartbox recording system running the turn-key Radiens software platform for data acquisition and off-line visualization and analysis.  Three SiNAPS pixel probe variants were used: (a) Four-Shank, 1024-channel probe, (b) One-shank, 256-channel probe with integrated flat optical fiber (for ontogenetic stimulation), (c)  Eight-shank, 1024-channel probe.
2. Results:
   1. Every penetration yielded usable single-unit and/or LFP activity.
   2. The senior-level post-doc was quickly trained on the Radiens Allego app and used the software seamlessly over the multi-day sessions to acquire data and manage recording sessions via its powerful real-time signal metrics and visualization features.   See the brief videos below to get a sense of the recordings and Allego’s intuitive UI and powerful real-time metrics and visualization.
   3. Recording artifacts associated with optical stimulation was workable and comparable with passive silicon probes.
   4. The resulting “big-data” data sets (multiple terabytes) were managed using the Radiens Curate and Videre apps, which are specifically designed for offline data curation, analysis, and visualization.  This includes an efficient pipeline to open neuroscience analysis frameworks (e.g., Kilosort).
3. Discussion:
   1. This lab experience successfully pressure-tested the NeuroNexus SiNAPS probes and recording/analysis system in a high-level lab with exacting electrophysiology standards.  Notably high-quality recordings were obtained within hours of arriving to the lab and our collaborator continued to record into the evening when we had to leave 3.5 days later.
   2. The SiNAPS probes were confirmed for use in optogenetic studies requiring localized optical stimulation via integrated fibers.
   3. The NeuroNexus Radiens software platform is effective for both turn-key neural recording from 1024 channels and efficient, intuitive data wrangling and visualization of “big data” neural data sets.

We have reached a significant milestone in our efforts to create increasingly powerful, user-friendly, and affordable electrophysiology tools and solutions that will drive progress in systems neuroscience.

Perhaps the most exciting aspect of this work is that these probes and solutions are available NOW for you to incorporate into your work. Please contact us for more information. 

Here is a 3D visualization of neural activity captured using a SiNAPS 1024-channel probe, shown in a brain-centered view.

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-shank 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)

Available Packages:

• Regular Packages
  • SiNAPS_1S_256-AVS256
  • SiNAPS_4S_1024-AVS1024
• Opto Packages
  • SiNAPS_1S_256-OAVS256
  • SiNAPS_4S_1024-OAVS1024

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

SiNAPS probe mapping

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.

SiNAPS optogenetic packages come with an attached single optical fiber for 1-shank 256ch and up to four optical fibers for 4-shank 1024ch designs. The placement of fibers on the 1024 design is unrestricted. Whether one intends to include a single fiber or more, they have the flexibility to position it between shanks or on any preferred shank location.

Please note that we provide flat fibers with 50 µm/62.5 µm, 105 µm/125 µm, or 200 µm/220 µm (inner diameter/outer diameter) options, as well as Lambda fibers with 105 µm/125 µm, 200 µm/225 µm, or 200 µm/230 µm (inner diameter/outer diameter) for SiNAPS Opto packages. For further information, visit the Optogenetics section.

SiNAPS Webinar Recording is Now Live!

The webinar recording is now available and ready for viewing! We are excited to share this valuable content with you. Please feel free to watch at your convenience.

Watch the Recording!