Can't Find Muscle-By-Muscle Wiring Data! Help!

I’m working on a 3D model that will use a self-programming memory algorithm (simple temporary brain) to coordinate the motor neurons that connect to each muscle. But I’m having trouble finding the information I need to make a table that shows where each of the muscles below connects to, what motor neuron goes where.

The following tables have some information but neither show the hookup on a muscle by muscle basis.

I also found the wiring diagrams in the paper “The Structure Of The Nervous System Of The Nematode Caenorhabditis Elegans, by J. G White” but that didn’t seem to show this level of detail either.

I’m hoping that someone might know where to find an online muscle-by-muscle hookup diagram or if that doesn’t exist then would know how to extract that data from the cell lineage data or as close as possible from the above tables.



Good project, but I’m afraid that the exact anatomical details of the neuron to muscle synapse mapping is still in progress.

The original listings of NMJs for the reconstructed animals done at the MRC did not attempt to distinguish exactly which muscles were being contacted (they did not trace the muscle arms back to the muscles). Such efforts are possible - see for instance our Quicktime movie of dorsal body muscles reaching to the dorsal nerve cord shown on WormAtlas.

There is a student currently trying to assemble a better mapping from the MRC anatomy data, but it is still in progress. I apologize that the following info seems a bit cryptic, but I’m trying to allow this student to announce the findings as a body of work.

In the meantime, you can presume that each motor cell connects to a limited number of muscles along the length of the nerve cords, and that it contacts every muscle in the region of its active zones. That is: arms reach directly across to the nerve cords from about 3 points along each muscle (see recent data from Peter Roy) to touch the nerve cord on the same side of the body (ventral muscles to ventral cord) (dorsal to dorsal). Each motor cell has a distinctive zone of NMJs that really does not overlap with its neighbor of the same type (so when DA4 stops making NMJs, DA5 soon starts to do so). Zones of output along the cord seem roughly equal in length for any given type of motor cell, but they differ a lot between types. Type AS axons do not come close to reaching their neighboring AS cell’s zones of output.

But the patterns are orderly and you can probably create a reasonable model already. Exact patterns for the nose and neck muscles are shown in detail in Mind of the Worm. They differ in that each quadrant gets somewhat different input (inputs to left and right muscles on one side are not equivalent - allowing the head to swing side to side in all directions)


Dave Hall

Hi David!

I have to say that I admire the work you (and others here) are doing. Not only is it scientifically valuable it’s also a highly educational internet resource. An excellent way to help teach the world science.

You are right on time too. I just finished the first step of the program, turning the changing shape of the worm into movement through water. It’s a simple no-frills program written in Visual Basic that can later be improved to render in DirectX but fancy graphics would only slow it down so for modeling a brain it’s adequate. The red circle indicates its head.

At the moment the shape is being changed by a sine wave generator. When it hits one side of the screen it reverses direction until it hits the other side then reverses direction again. The slide control changes the viscosity. At minimum it makes no progress at all like it’s trying to swim through air. At maximum it’s digging into the agar and making good speed.

The mechanics of movement along the X axis is calculated using a Fourier Transform algorithm that compares the current shape to the previous. The Y axis is brought into proper alignment by calculating the two centers of gravity. It’s a fast and easy way to do it. If need be, I can add rotation so it can swim off in any 3D direction but once again getting fancy eats up CPU time that might best be used on modeling the brain.

In case anyone is interested in working with the program the source code and PC compatible executable that will run without needing to be installed in a directory is available here:

I can see that the data needed to make a working model of its brain is still being researched. Would require a schematic showing all of the synaptic connections in and around the ring. I have a hunch as to how it might be working, in fact the first thing I looked for was a ring of neurons due to that giving it the ability to sense “around” itself. I found that it gives a creature the ability to intuitively know where something it is looking for or is chasing has gone when it’s out of sensory view. It would otherwise randomly have to search back and forth. I discussed how that works in the Kansas Citizens For Science forum. I can also provide the source code if anyone is interested in experimenting with it.;f=3;t=001464#000000;f=3;t=001420#000000

It’s too early to tell if C. elegans is using a self-learning method such as this. The ring shaped brain could just be a coincidence. My hunch is based upon this being the easiest way to wire a small number of neurons into a functional brain that I have ever experimented with. With a complete schematic showing all of the synaptic connections of a C. elegans and the motor neurons to each muscle I could look to see if I recognize the circuit, but it looks like that will have to wait until the data becomes available. So I certainly hope that the student working on the motor control is able to make good progress and their findings are soon included in the WormBase. I consider the work they are now doing very important and hope that other students are encouraged to help do the rest of the circuit. And I would like to suggest that the locations of each neuron body, synapse, and path of each axon and dendrite be given an X,Y,Z coordinate and provided on WormBase as an easy to decipher text database so that the entire circuit can later be drawn in 3D. Could then use fancy graphics to take a “Fantastic Voyage” inside the worm’s working brain. I think people will like that just because it’s cool. Learn a little while having fun, sort of thing.

I’ll be anxiously awaiting the new data. And I promise not to tell the ID’ers about this forum unless you want to add a little comedy to the site. :smiley: But I can’t say how long it will take for them to find it. No science forum is safe from their wrath. It is though somewhat interesting how it has motivated some to learn science they would not have otherwise taken the time to learn. In the end the controversy could become a good thing for science. I hope so anyway.

And if anyone is wondering what kind of science I do, I own a dinosaur tracksite in Massachusetts and actively promote science on the internet and elsewhere. Now have four college students, two who recently graduated and are now making a name for themselves, writing papers and doing other things related to local paleontology.

Anyway, I’m hoping that the very important work being done on your end continues to go well too. And if there is something that I can do that would be helpful to you then let me know. The model I’m now working on now might not have very much scientific significance without a realistic model of the C. elegans brain to power it, but maybe there is something I can add to it that I haven’t thought of yet or another program that is needed. From your description of the wiring I should have no problem adding a self-learning memory array but it’s hard for me to say if that would be of much value. It would be the first time I used it power a critter that moves with a sinusoidal pattern so it might be interesting to watch it figure out how to get moving then later add a colony of bacteria to see if it displays realistic feeding behavior. But still, there is no telling if that’s how their brain works or not. If there are similarities then the model would be of some value. If not, then it might not be much more than an interesting screen saver.