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Spikes from an Earthworm?

Here are two screenshots of action potentials (or are they) recorded today from the ventral nerve cord of an earthworm.  The worm was anesthetized and a crude dissection was done, revealing the cord.  One SpikerBox electrode was placed next to the cord, the other about 2 cm away in the worm’s muscles.  As you can see, the signal to noise ratio is low, but the shape and timing of these signals suggest that they are spikes.

Used the SpikerBox from BackyardBrains for amplification and xoscope (on linux) for visualization.

Regenerating Worm

This Eisenia hortensis was transected about 8 or 9 segments behind the clitellum 18 days ago.  It has regenerated about 7 segments, and is able to crawl.  Use of the new segments appears limited; they seem to work more as a unit and less as independent units the way normal segments function.  Updates will be posted occasionally.

Below is a video of the worm crawling.  Note the last several segments being pulled behind the rest of the worm rather than crawling as independently as the other segments.

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Squirming Worms

Here’s a video of worms in a tangle burrowing underground away from the light after being placed in a new compost bin.

You might also notice some mites scurrying along the worms.

Harvesting Worm Compost

Here are some photos (in a Facebook album) of the process of harvesting the compost from an old bin and adding a new one.    The only tedious part is separating the worms from the compost – but they actually help by digging themselves deeper into the dirt pile to escape the light.  The end product is a big pile of worms to be returned to fresh bedding in a new bin and an even larger pile of excellent compost.

Earthworm Neurophysiology in the Works

I’ll soon be combining xoscope, the SpikerBox, my favorite thin-skinned soft invertebrates, and this newly-described earthworm cage to record action potentials.  Seems like the perfect project for the winter break.  Pics of action potentials will appear on my Research page as soon as they are available.  After that: using the SpikerBox to monitor neural responses to stimuli of various sensory modalities.  Watch for it!

Thanks to the people at Backyard Brains and at JUNE for helping to make this possible. —————————–

– An account of the first use of the SpikerBox in my lab appears below…

A.P.portunity Missed…

I recorded an action potential today, from an unfortunate insect that happened to be roaming the floor of the empty animal quarters.  I think it was an adult mealworm.  I anesthetized it (snow in a small container) and removed a rear leg; leg turned out to be way too small for the pin electrodes on the SpikerBox.  So instead I impaled the head of the insect (while it was anesthetized) and put the reference electode in the abdomen.  Sounded like spikes, and the rate changed if I blew on the bug or touched a leg.  Hooked it up to xoscope and saw what looked like spikes.  Thought I saved a beautiful action potential – could have come out of a textbook.   This is why you should always know the equipment before you start.  This was my first serious use of xoscope, and what was saved bears no resemblance to what I saw.  No saved data, no screenshot – nothing.   I now know how to save data (at least, I think I do) and I can take screenshots.  For your viewing pleasure I present xoscope displaying a brief segment of “The Cha Cha Slide” –  OK – I just grabbed my daughter’s mp3 player as an input, and this is what I got.  I also present a graph of a saved segment of the same song.  No action potential, but evidence that I can take screenshots and save data.  I’ll try again soon.

SpikerBox Make-and-Take

Preparing to record from the neurons in the leg of a cockroach.

Albion’s Neuroscience Program now has two SpikerBoxes.  The device, created by the innovative people at BackyardBrains.com, allows easy recording of invertebrate neurons.  First-year student Brendan Wass and I attended Backyard Brain’s first Make-and-Take Workshop in Ann Arbor.  We each built a SpikerBox and learned how to use it.

Video (below) shows a cockroach leg being stimulated by the output of an MP3 player.

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