On June 30, 2017, Eyewire launches the Mystic Expansion. For the first time, we’ll map a new dataset! Curious why? Check out the Q&A below with Ashwin Vishwanathan, Mystic’s lead scientist.
What is the aim?
We are hoping to test ideas regarding the connectivity of a some very special neurons in the hindbrain of the larval zebrafish.
Why are these neurons special?
These neurons are called “integrator neurons”. They are involved in transforming eye-velocity commands into eye-position signals, which literally is “integration” in the calculus sense. Imagine a signal that looks like a pulse (a quick on and off), these neurons take such signals as their input and transform them into a step ( a sustained on) as the output.
What is known so far?
So far it is known that these neurons perform this task for various types of eye movement, and that these neurons are found across multiple species (fish, cats, primates etc.). It is though that for these neurons to be able to perform this transformation, they need to be ‘connected’ in a certain manner. One such theory is that of ‘positive feedback’, where the activated neuron excites other neurons in a cascade that would allow for a pulse to become a sustained step. But there is no evidence for this. This project hopes to shed some light on that.
How do we do this?
We start by optically imaging the activity of neurons in the hindbrain to find ‘integrator neurons’, by taking multiple photographs of the activity in quick succession, to make a movie. We analyze these movies and look only for those neurons that are performing this transformation (pulse–>step). We then prepare the same brain region for electron microscopy. Then we locate the same neurons from the optical images in the electron microscopic images. From the electron micrographs, we can locate every synapse onto and from an integrator neuron, that is all partners of these neurons.
Where do citizen scientists come in?
To uncover all the synaptic partners of integrator neurons, we plan to reconstruct all the identified integrator neurons. Following this, we will locate all pre and postsynaptic partners of these integrator neurons. Assuming on average every integrator neuron has a 100 synaptic partners, that would mean reconstructing a 1000 neurons for every 10 integrator neurons. You can see that this quickly adds up if we are to reconstruct ten of integrator neurons. To do this, we seek the help of you – the citizen scientist, to help identify and reconstruct the postsynaptic partners of integrator neurons.
On June 20, Eyewire HQ hosted a livechat Q&A. In case you missed it, here are the questions and answers.
How is gameplay different in Mystic?
In Eyewire, players access cubes by start playing menu until they attain a rank of at least Scout. At Scout, players are able to access cubes to flag them directly from cell overview. At Scythe, players can directly edit the consensus of cubes via overview in a process called Reaping. In Mystic, there is no normal cube submission: all cubes are reaped.
Nseraf: What are the requirements for someone get promoted to Mystic?
Qualifications are based on Reaping and Completing accuracy with respect to missed segments. HQ also considers how active a player is. We will release the exact qualifying metric soon.
Nseraf: Say that a player is a scout, and they get scythe promo during HQ-promos now in June promo cycle (after week comp.) Is there going to be a minimum amount of time they’ll have to spend as scythes before they can apply for mystic?
For Mystic, we are issuing promotions alongside major competitions. So following the June 30 promotion, the next class of Scythes will advance on Aug 25. We may consider another round in July.
Nseraf: Are mystics going to be like moderators in terms of promos? Meaning HQ-only or are they going to be like scouts and scythes, meaning existing mystics will be able to sponsor and thus also help train future mystics? (I’m thinking like mods at least at first, but want to make sure lol).
Mystic promotions will be won from HQ based on qualifying metrics.
Nseraf: Are mystics promos going to be application based (from blog post form like other ranks) or is it going to be HQ-invite?
Scythes will be able to apply via the forthcoming Mystic Overview blog. Mystic promotions will be issued from HQ, not player sponsored.
Nseraf: Will mystics have a (different) chat colour? (Like scouts/scythes/mentors etc) and if yes what will that colour be?
Yes, but the color will be revealed later 🙂
Nseraf: I’m guessing the image here is the Mystics rank badge? If yes I love it!! 🙂
Yes that’s it!
Nseraf: Are there going to be any mystics-related badges other than the rank one?
Crazyman4865: Since mystic will have story, how will that be progressed? As in, will there be quests/missions/etc or do we just play to unlock more?
The first chapter is in this competition but there will be more. Eyewire doesn’t yet have a quest/mission system but the team versus will sometimes have story added. Also there is a new game in the works called Neo, that won’t be out for a while yet, but Mystic will likely play a role.
Nseraf: Since scything (and/or completing) accuracy(ies) are now going to be measurable are they going to have badges? Like “this scythe/mystic has kept a scything accuracy of ##% for <time period>” (With time period increasing per badge) Or any other related badges?
Accuracy badges have been considered in general for Eyewire but this is all TBD. We are working on a way to display Reaping and Completion accuracy in profiles.
Nseraf: Is it possible/will we trace some glia at some point in zfish dataset?
There are no plans to trace glial cells.
Susi: Will there be a mystics log?
Yes, eldendaf is developing a special Mystic section in Scouts Log.
KrzysztofKruk: Will computer/internet requirements be higher than in the EW or the same?
Eyewire Dev Kelv: Yes, Mystic will require more GPU memory; however, we have settings that allow you to view the cube with reduced quality. It will also use more cpu memory but will work on most computers.
Susi: Are zfish cells now that mystics are coming out of beta testing going to continue as they have been (tracer A then tracer B) or are they going to be like scythe forts, many ppl tracing each cell each to a branch etc.
The format will remain with one player at a time on each cell.
KrzysztofKruk: Will scouts/scythes be able to flag cubes in the new dataset or, at least, inspect the cubes?
Mystic will only be accessible via rank Scythe. You do not play cubes, only reap.
KrzysztofKruk: Are there some levels of those new cells (like level 1, level 2) or they all will be treated the same?
All the same for now.
KrzysztofKruk: What will be the maximum amount of points possible to gain from a cube?
Because Msty does the cubes first and gameplay is all reaping, it’s currently only the scything bonus. We are working to create an appropriate point reward for Mystic.
Nseraf: Will Mystics receive any points/bonuses for Mystic activities? Any (increased) sc bonuses for completing a certain amount of cubes/cells in zfish dataset?
Currently, you will only see the 150/30 point scything bonus because we’re still building the full point system. There also won’t be SC bonuses for the time being because of a different pipeline for deciding when cells are really done. But we’ll be working on all of this.
KrzysztofKruk: Will “last scythe/mystic wins” rule still apply?
KrzysztofKruk: Will there still be voting for the cubes (2SC to complete)?
No voting since Msty plays and you reap. There is a similar system in Player A / Player B claiming and completing entire cells.
KrzysztofKruk: The blog post says that there’s a new AI used. Does that mean that there will be like more checking the seed, less adding new segs?
Msty does most of the work with growing segments in cube. You’re more likely to need to add extensions but not necessarily from the seed.
Nseraf: If scything accuracy is going to be a promo requirement what happens if a scythe-now-mystic falls under that accuracy threshold for any period of time, be it 1 hr, 1 day, weeks or months?
We currently have no plans for demotion. Since only highly skilled players will qualify so demotion should not be an issue.
Nseraf: How many cells/neurons are in Mystic?
There are 3,000 total cells. Roughly 1,000 are not cut off by the edge of the dataset.
KrzysztofKruk: Will there be some tutorial to show how some structures in zfish cells should look (how thin branches can be, what structures (boutons, synapses, autapses)?
Yes, we are making a demo video and a comprehensive blog. There will also be a Scouts Log section for Mystic.
KrzysztofKruk: I’ve read that in the new dataset there will be many mitochondria, vesicles, etc. Should those be traced or left unselected?
Yes, the new dataset shows all the intracellular structures that aren’t visible in Eyewire. Players should fill everything in zfish. The AI does not separate the intracellular structures from the overall trace of the whole branch.