Coming to the Society for Neuroscience meeting is always great fun for us, and it was especially true this year as we unveiled the third generation of our optogenetic prototype and actually did some experiments at our poster! Earlier this year we sponsored a student design effort to build a portable optogenetic rig using cholinergic ChR2 (Channelrhodopsin) transgenic fruitfles from our collaborator Stefan Pulver. We’ve been hard at work over the summer improving the prototype with two design cycles, and here is version 3.
We brought the prototype to SfN; Stefan brought the special flies. Here at Backyard Brains we believe in real-time posters, so if you came by, you would seen us explaining how the prototype worked while Stefan was busy preparing the fruitfly larva for recording. Below Nature reporter Ewen Callaway talks to Stefan as he tries to use our micro-rig.
Ewen subsequently wrote a nice blog post on our gear for the Nature News site, but the best treat of all for us was returning to “Neuropod,” the Nature Neuroscience podcast. We were on the podcast three years ago when we first tried to present our gear and nothing worked. But we kept hacking away, and now, with all our gear fully operational, we were happy to bring the first spikes recorded live on Neuropod!
As astute listener may wonder why you only hear the standard cockroach leg spikes on the podcast. Where are the fruitfly muscle recordings? Weren’t we also talking about some optogenetic device? Show the data! We admit, it was still relatively early in the day when we spoke with Ewen, and Stefan was still trying to get his dissection right (he remarked the monocular microscope made the dissection difficult, and he would have preferred the gooseneck dissection lights to be longer. Noted for Gen4). But Stefan stayed focused, and at 2 PM Sunday afternoon we successfully recorded the critical piece of data: the electromyogram from the fruitfly muscle during presentation of blue light. It’s noisy, but in the recording below you can hear the increased activity from the muscle at ~2 seconds when Stefan turned on the blue light. The blue light caused the cholinergic motor neurons to depolarize, resulting in muscle contraction.
Expect us to release the designs for the micromanipulator (you could 3D print it yourself!) and LED control circuit in a month or so.
It was a busy SfN for us, as we also ran a symposium on “Low Cost Neuroscience” with our colleagues Bruce Johnson from Cornell, Jeff Wilson from Albion, a high school teacher from the D.C. area, Raddy Ramos from New York Institute of Technology, our friend Stefan, and our keynote speaker Ben Robbins, a 6th grader from Novi Meadows Middle School. Mr. Robbins taught the audience how to successfully do outreach to 5th graders. We don’t have access to age data of presenters at SfN, but we would venture to guess Mr. Robbins may have been the youngest presenter ever for the society.
Scientists, with their huge intellect and famous experiments, can sometimes be intimidating to approach. Thus, we were a bit cautious and sheepish when we asked Mr. Robbins if he would let us take a picture with him. Thankfully, he was cool with it.
Photo by Jeff Wilson
You can watch Mr. Robbins’ talk below in all its lo-fi hand held camera glory. Don’t worry, the shaking slows down about 20 seconds in.