Silicon Neural Probes
In Vivo Performance
Copyright Cambridge NeuroTech 2014-2016
Advanced Electrophysiology Systems
World-leading silicon neural probes enabling high-yield single unit
recording with optogenetics and drug delivery
Frustrated by poor chronic performance of your silicon neural
Broken too many expensive, fragile silicon neural probes?
Data contaminated by photo-electric artefacts?
Our next-generation silicon neural probe technology overcomes these
common problems and offers you even more, including:
Superior chronic stability - unrivalled in vivo longevity -
record the neurons you want across many days to weeks.
Minimal photoelectric artefacts - the only silicon neural
probes on the market optimised for single unit recording +
Microdrive compatible - simple mating; guaranteed alignment
with drive and co-alignment with fibre optic / drug cannulae.
Create user-defined 3-D arrays - innovative stacking silicon
neural probe architecture with freedom to choose vertical and
Enhanced signal to noise ratio - stabilised electrodes with
typical 25 - 35 kOhm. (~2x - 10x better than the competition!)
Ultra-thin yet robust - 15 micron thin probes for minimal tissue
damage yet still able to withstand considerable stress
Proven technology - our silicon neural probes are used in
everything from mice to monkeys - read the first publication
using our probes.
Yeah, yeah that’s just your best-case example! Nope, read on...
Each line in the graph above plots single unit yields over many days recorded from neocortex (2 animals) and dorsal striatum
(2 animals) with silicon neural probes in freely behaving rats. Although mounted on our precision microdrives, the probes
were NOT moved during this experiment.
No other electrodes, probes or whatever (!) can yet match this degree of in vivo performance with repeatability and reliability.
We can’t promise this will always work in every animal but for sure our technology gets you as close as you can get to the
elusive goal of recording the same neurons for extended periods of time!
So your probes are minimally-sensitive to optogenetic stimulation artifacts, huh?
When light strikes a metal electrode it commonly causes a photoelectric artefact due to the Becquerel effect. This can throw
your amplifiers off and contaminate your signal with artefacts that may mimic spikes so single unit recordings during
optogenetic stimulation have proved tricky so far....examples of this in the literature can be found in Cardin et al., 2010 and
Park et al., 2014; Fig. 4).
As standard, all of our probes are purpose engineered to minimise photoelectric artefacts thereby enabling seamless single
unit recording during photo-stimulation..... even with the smallest, hardest to record neurons in the brain - cerebellar granule
Example single unit data from neocortex recorded wirelessly in a freely behaving rat.
Spike-sorted from 16 electrodes are plotted in each colour-coded column.
A shows an excerpt of data recorded on a probe electrode in mouse cerebellar cortex.
Negative-going spikes are attributable to a photo-identified granule (overlaid spike-
waveforms shown in B). When 10 mW of 473 nm blue light illuminates the tissue, ChR2-
expressing mossy fibres provide a modest post-synaptic drive to the granule cell, for the
duration of the stimulus, The expanded time-base, shown in C, illustrates the magnitude of
the photo-electric artefact compared to the granule cell spikes (indicated by arrows).
Data provided by Tahl Holtzman, Austin Graves, Adam Hantman and Tim Harris at The
Howard Hughes Medical Institute Janelia Research Campus, USA
Read the first paper using our
silicon probe technology...
So you say your probes are long-term stable in vivo, eh?
Sure! Let’s look at a probe that has been in the same location for 30 days....
Data speaks louder than words!
Watch this short video of live data from a 32 channel probe in a
freely behaving rat, using our wireless telemetry
So how do I co-align fibre optics / drug cannulae with probes AND make 3-D probe
The ability to record spikes and deliver light to the same region is a very useful weapon to have in your electrophysiology
armoury but presents some ugly mechanical problems. Our innovative nano-drives are purpose-designed to mate with our
probes to guarantee true and square alignment between the probe and drive-axis, but also to allow you to co-align up to 2 fibre
optic cannulae / or a fibre cannula with drug cannula too! What’s more, our probes are stackable too, allowing you to create
your own 3-D arrays with complete freedom to position your probes to suit your specific targets.
Sounds great, but silicon neural probes are
really fragile and break easily don’t they?
That is certainly true of our competitors - one little slip... and boom, there
goes your expensive probe! Take a look at this brief video and decide for
yourself just how forgiving our 15 micron thick silicon neural probes are:
Will this work in my lab? Can this really beat
other silicon neural probes and tetrodes?
There are no certainties in life other than death and taxes (Benjamin
Franklin, in a letter to Jean-Baptiste Leroy, 1789) but we’re confident that
our probe systems offer you the best chance of achieving similar high
quality data with long-term chronic stability. Our tissue non-reactive,
impedance-stable, ultra-thin silicon neural probes, at just 15 m thin outperform thicker silicon probes from our competitors
(typically 25 - 100 microns thick with non-stable impedance) and our ability to provide total integrated probe solutions with
wireless telemetry and optimal surgical technique give you the best possible chance to rapidly upgrade your experiments
to harvest more data per animal, for longer time-periods and with minimal damage to the neurons you’re trying to study, whether
you’re a new-starter or experienced veteran.
Below are images of data from hippocampus and you can read the first publication using our probes here - Nature
Also take a look at our user-community testimonials here...
fibre optic cannula alignment with silicon probes
(click to enlarge)
You’ve got a probe that can record the entire cortex at single unit resolution?!
Sure! Here’s some data to get you going...
Simultaneous recording of CA1 hippocampal and cortical units using our H3 1x64 probe in an awake, head-fixed mouse. Probe location
is indicated by Dye-I fluorescence (yellow in the image on the left; note superimposed camera-lucida schematic of cortical and hippocampal
neurons) and spike-sorted single unit data from the relevant regions are shown on the right. Data provided by Yurii Vlasov (University of Illinois
at Urbana-Champaign, USA), Nick Sofroniew, Karel Svoboda and Tim Harris (The Howard Hughes Medical Institute Janelia Research
Our latest high-resolution probes meet the challenge of offering high-resolution, single unit recording across a depth of ~1.6
mm whilst maintaining small probe dimensions (< 80 micron probe width for 64 channels!) because size really matters for long-
term in vivo stability - something our probes are exceptionally good at (see next section). We’re really excited about these
probes because it’s now possible to record the entire depth of the cortex simultaneously and of course much more than
NEW TECHNOLOGY BREAKTHROUGH
What about data from other labs....?