Frequently Asked Questions about the NeuroLight Optoelectrode

How many LEDs can we have on a shank?

• Current version we are disseminating has 12 LEDs, 3 on each shank. For the next version we are planning to make a decision among several configurations, but definitely more than 32 microLEDs per probe. We have not determined the final number yet. We should be able to accommodate 128 individually controlled microLEDs.

What is the approximate volume of tissue illuminated by a single LED?

• The LED has a diverging Lambertian profile with an angle, and we have succeeded in optical stimulation of neurons within tens and hundreds of microns from a single LED. However, this
  probe is not meant to illuminate a large portion of the brain; it is for local stimulation, possibly modulating at single-neuron resolution.

Do you plan on other wavelengths than blue, for example, yellow?

• Our next research goal is making color LEDs/stimulation. We are currently providing blue only. It is unlikely to provide other wavelengths, such as yellow/red in the next year, but it is coming.

Will the LED power decrease during recording?

• We have a longevity testing of the LEDs; the power reduced a little bit but not significantly. Probably fine for in vivo study, as there are a lot of biological variables that would impact stimulation more than the probe technical side. The reduction of the optical power is about less than 10%, pretty minor.