Dave and Joanna at Willemstoren Lighthouse, January 16, 2016
During my 25+ years performing neuroscience research, I have used invertebrates to study how hormones, drugs, and experience change the structure and function of the nervous system.
For my PhD dissertation, I examined how the circuitry of the central nervous system changed when the caterpillar of the tobacco hornworm, Manduca sexta, undergoes the metamorphic transformation to a moth. In the process, I identified a collection of pre-motor interneurons based on their unique forms and patterns of electrical activity, and examined how they changed during metamorphosis. During this work, I identified an unusual pattern of electrical activity in neurons that appeared to be specific to the pupal stage.
Later, I studied the influence of learning-related genes on the structure and function of the synapse in fruitfly, Drosophila melanogaster. The neuromuscular synapse, which mediates communication between the nervous system and muscle in the larval Drosophila, has served as a powerful model for the discovery of genes important for stability and plasticity (the ability to change) of synapses in general. Our work demonstrated important roles for genes such as ADF1 and AP-1 in regulating the physical size and electrical strength of synapses.
As a staff scientist at NIH, I studied the ways in which volatile anesthetics (the ones you breathe) alter the excitability of neurons (nerve cells), and the synaptic communication between them. Again using the larval Drosophila synapse, I found that volatile anesthetics such as isoflurane (an ether modified by adding chlorine and fluorine atoms) reduce the excitability of neurons, and thereby reduce the strength of synaptic communication. Further, we explored the role of an ion channel that releases calcium from storage inside the cell, the Ryanodine Receptor (RyR) in mediating the anesthetic effects of another volatile anesthetic, halothane. I used both patch-clamp electrophysiology and direct imaging of calcium inside cells to show that halothane causes the RyR to open and release calcium, while at the same time the electrical potential across neurons’ membranes becomes more negative, making the cells less able to be excited.
In 2013, I decided to refocus my efforts from research to teaching. I became a lecturer at the University of Maryland, College Park, teaching at the Universities at Shady Grove Campus. I teach Mammalian Physiology, Principles of Neuroscience, Cell Biology Laboratory, and Neurobiology Laboratory to students in the Biological Sciences program. My role as a teacher has motivated me to begin the Elysia project, as a way of introducing students to the ecology, behavior and neurobiology of these unique creatures.
Hi Dave, I too am obsessed with sacoglossan slugs (elysia included) and spend alot of my time diving and doing macro photography in Singapore waters where there has been quite a surprising number of these sappy slugs! I’ve read many of your blog entries more than once and enjoy them immensely, learned alot. I am happy to share some of my photos of the species seen here if you are so inclined to see them.
I would love to see them, and would be happy to post photos! Would you like to do a guest blog post of some of the species you have photographed?
That sounds intriguing! perhaps we could discuss if you like , my email is provided
Hi, Dr. Sandstrom! I’m so excited to find your website. Long story, but in recent years I sold it all in NYC changed it up, and now live and dive (mostly) all year in Cozumel – with the occasional excursion, though not recently… And I have fallen in love with photographing the less celebrated macro sea life here, especially the local elysias! Our main ones are elysia crispata, elysia ornata, and the painted elysia (thuridilla picta – after the last 45 mins., I guess it’s among the Plakobranchidae but not truly an elysia?). Anyway, I also hunt for nudibranchs, sea snails (flamingo tongues being my main obsession – and best collection of behavior shots) and any other little odd-balls I can find. It’s so hard to find more info! I do my best with the Humann/DeLoach/Wilk books and google, etc., but the Solar Sea Slug Blog was such a fun find. I have questions! :). I’d also love to share photos or do any local citizen science stuff – right now, we’re seeing crispatas (“lechugas” down here…) on literally every dive – of all sizes. I also do a blog, and want to give some very basic descriptions of behavior, but am never sure. Anyway…sorry so long, just a big slug nerd, and am very happy to make your acquaintance. If you would ever be willing to email or answer things, or review some shots that either I have questions on or that might show neat behavior, please let me know. (you can get a sense if you want on my Instagram: @schreckrachel – not all slugs, but…close! haha) OK, thanks so much, and I read your most recent (I think) post – I’m sorry that COVID-19 interrupted your lab work, too, of course. I hope things can get back on track very soon. And that you and yours are all OK, or as good as can be expected. Thank you. Sincerely, Rachel Schreck
Hi Rachel,
Always exciting to find another slug enthusiast. I am hoping that the slug lab will be in full swing in a few months after the pandemic quiets down. The pause has given some time to clean out the system and try to focus on better culture methods for Bryopsis plumosa. Feel free to post questions here, or though the contact page.
Dave
OK, will do. I’ll look forward to more when you’re back up and running. My first question is about the elysias’ eggs. I see in your article on keeping them that they lay those large spiral clutches of eggs. In 5 years, I’ve never seen those in the wild, yet if I understand right, your adults would do that quite frequently, sounds like. I’ve seen one other kind of what I assume to be nudibranch or slug eggs, but they had a much different shape (though were seemingly laid right on top of a cyphoma snail’s eggs. ??) Anyway, question: what are the typical preditors of elysias and/or their eggs? I didn’t see that, exactly. Thanks!
Hi Rachel,
I am trying to get the colony restarted and the web page cleaned up, so hope that there will be less of a delay in responding to questions.
With regard to the location of the eggs, I have also never seen eggs in the wild. This is one of the confusing issues with E. crispata, in that they always seem to be found on rocky reefs without much in the way of food. In my mind, they sneak off at some point and find Bryopsis plumosa to eat and lay their eggs on, because there does not seem to be any evidence that baby E. crispata eat anything else.
As far as predators, Elysia probably taste pretty bad because of their diet, but there are probably crustaceans and fish that will eat them. Mike Middlebrooks has used blue crabs as predators in his assays, and I have seen peppermint shrimp (Lysmata sp.) eat youngsters. Flatworms and annelids prey heavily on newly hatched Elysia if they are allowed into the cultures.
Hope this helps
By the way, your photos are gorgeous. Let me know if you are interested in doing a guest post of some of your Elysia and nudibranch photos.
Hi Dave,
I’m a researcher at UT Austin doing studies on Caulerpa proteomics…and also Halimeda. I found an adorable Elysia tuca but seems to be a single slug. Can they reproduce on their own? I know they are hermaphrodites, but my understanding is that they prefer mating? Also how can I send pictures?