Science Buddies: "Ask an Expert"

Hi,

I’m interesting in doing an experiment with Planaria memory, which would require conditioning equipment. I understand how training would work but I was wondering, if I were to try to expose the Planaria to a drug solution, how might I do this in cohesion with training? Would I place the Planaria in the conditioning tray and train them until they show signs of memory retention over time while placing them in the drug solution only during training or would I use the drug solution in their primary habitat?

Thanks!

Hi funnyturtle79,

This experiment sounds really cool!

I think what is most important here is that you stay consistent. I'm not sure how many trials you are planning to do, but make sure the way you administer the drug solution (the drug type/amount would be the independent variable) is always a constant.

You should also take into account what you are trying to prove. If you are trying to test if the drug solution affects the Planaria long term, it may be a good idea to add the solution to their primary habitat. If you would like to test how the drug affects the Planaria immediately after exposure, adding the solution during training may be the way to go.

Some questions you might want to ask yourself are:
-how long do you want to expose the Planaria to the drug solution?
-how much of the drug solution is available to you?
-how many organisms do you have to work with?
-if the Planaria will be in the solution for a long period of time, how does the drug concentration change over time?

It may be worth doing extra research on the drug so you understand more about how it works and how it changes over time. Some substances become less effective as time passes, so this could potentially change your results.

I wish you the best with this project. Please let us know if you have any more questions or follow-up questions!

Emma

Hi Emma!

Thank you so much for your help! I would like to see how the drug affects planaria memory after fragmentation to see if the drug improved or worsened the memory of the planaria but I am having difficulty in coming up with a way to quantify whether there was an improvement or not? Also, I was wondering about what the measurements of the conditioning tray would be? I am unfamiliar with training them, so any help with this would be much appreciated!

Thanks!
Funnyturtle79

Funnyturtle79,

No problem!

To quantify whether there is improvement or not, you may want to record how many times the Planaria complete a task correctly and compare the control group to the experimental group(s). For example, if you do 15 trials on each Planaria, count how many times each organism completes the desirable task. You may find that the Planaria with the drug solution complete the task correctly 10 times while the group without the solution only complete the task 5 times. Another approach is to test how fast each group learns. For example, the group with the drug solution may start completing the task correctly consistently after 15 trials while the control group takes 30 trials. Your definition of "consistently" may mean that the group does the task a certain number of times in a row. (Please know that these numbers are completely random).

I have to admit that I have never trained Planaria before. I have, however, found some resources that might help you out. From my understanding, Planaria experiments usually involve the use of light and shock to condition the organism. There are also experiments where Planaria are put into the bottom section of a T or Y shaped maze and are either part of a control group or are shocked when they turn to a specific arm. (For example, if the Planaria turns left, it is shocked, but if it turns right, it is not shocked.)


Here is the Manual of Experimentation in Planaria from Tufts University. It is a very long document, but it certainly has some useful information to skim over. I think you may be able to learn a thing or two from page 4 under the heading "The Planarian as an Experimental Animal" (this is the 12th page of the PDF).
https://ase.tufts.edu/biology/labs/levi ... Manual.pdf

Here is another resource you may find helpful. It is an article regarding a study on Planaria memory, and it has many sections regarding topics like training procedure, feeding, and data analysis. I thought this article was very easy to understand and had a lot of helpful ideas.
https://jeb.biologists.org/content/216/20/3799

Finally, here is one more resource by the National Center for Biotechnology Information. This also has sections that may be worth looking over.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6701699/


I hope this helped somewhat. Please let us know if you need extra guidance or clarification. This project sounds like a lot of fun, and I hope you get the results you are looking for.

Happy experimenting,
Emma

Hi Emma!

Thank you so much for all your help and the resources you provided! I will definitely consider those! For the training method, I am unable to access a shocker but I was wondering if you have any other recommendations for other ways of training them?

Thank you so much again!
Funnyturtle79

Hello again,

I had a feeling you would be unable to access a shocker. You may be able to use a positive stimulus -- like food -- instead of a negative one -- like a shocker.

Science is all about getting creative, so there are a couple ways you might be able to do this. Again with the Y or T shaped maze, you could use food instead of a shocker to test if the Planaria remember which arm the food is in. You could also pair the light with food. I am not sure how Planaria act in nature, so pairing light with food might intersect with natural behaviors. This can be tricky. I was thinking you could either see how they respond to certain patterns of light (for example, provide food after three blinks of light, but no food after two blinks), or see how they respond to different colors of light (for example, pair food with green light but no food with red light). It's your experiment, so don't be scared to brainstorm!

As always, don't hesitate to reach out if you need anything!
Emma

Hi Emma!

Thank you so much for your help! I will definitely look into that!

Thanks again!
Funnyturtle79

Hi!

I was wondering if you have any recommendations on creating a habitat for the planaria? Can they be stored in jars and be cleaned periodically? Or do they require a full fish tank? What is the best way to ensure longevity but also costing a minimal amount of money?

Thanks!
Funnyturtle79

Hi Funnyturtle79,

I was reading through this thread and found your experiment idea to be very interesting! Emma also had some great ideas on experimental procedure.

I found a resource from wardsci.com that I think will be helpful as you figure out how you will raise and experiment with your planaria (here's the link: http://www.wardsci.com/www.wardsci.com/ ... anaria.pdf). I don't know much about this organism, but I'm happy to help if you have any more questions .

Good luck with your project!
Neha

Hi NehaK6,

Thank you so much for your help!

Funnyturtle79

Hey Funnyturtle79,

I'm so sorry for the delay, but I also found a couple resources that may be helpful to you. Neha actually already included one that I was going to suggest!

Here is a resource that gives some general information about planaria. The page also has some links that will help you find information about caring for planaria and using ethical research practices:https://www.georgefox.edu/academics/und ... 20reasons.

Here is another website that I think will be very helpful (I found it very easy to navigate): https://www.carolina.com/teacher-resour ... tr10534.tr

A couple tips I pulled out of this source are:
-make sure you allow proper air flow into the habitat
-water changes should always be done with spring water (if tap water is the only option, use a water conditioner first)
-be aware of the temperature of the habitat
-an 8" culture dish is a suitable habitat

This resource is less detailed, but it does have some information about light cycles and water changes: https://ase.tufts.edu/biology/labs/levi ... anCare.pdf

Lastly, here is a resource that mentions using a Ziploc container for housing. This is a very inexpensive option that may be of good use to you: https://lab.research.sickkids.ca/pearso ... earson.pdf

Some personal recommendations I have are...
-consider including hiding spots in the planaria habitat to imitate natural conditions
-keep in mind how long you would like to keep the planaria. This will affect how you take care of them
-22 degrees Celcius seems to be the target temperature for the habitat

To ensure longevity, the best thing you can do is be diligent about maintaining the water conditions. Planaria are very sensitive to the water they live in, and cannot survive in contaminated or dirty water. Regular water changes are essential.

As always, let us know if you have any more questions!
Emma

Hi Emma!

Thank you so so much for all of your help!

Thanks again!
Funnyturtle79

Hi!

Does anyone what would be the best way to measure micrograms? All of the scales online seem to only measure in milligram increments and was wondering what would be best for micrograms?

Thanks!
Funnturtle79

Hello,

What are you planning to measure, and how many micrograms are you trying to measure? I know there are a couple ways to make a DIY microgram scale, but I'm not sure how accurate they are.

If you are trying to measure out a substance/solute, you may be able to dissolve it in a solvent and measure out the solution so that you have the correct amount of solute. For example, if you dissolve 1 gram of a substance in 10 mL of a solvent to make a solution, 1 mL of the solution would give you 0.1 of a gram of the solute. Obviously, you would use much smaller values for the solute.

This is a really good question, and I wonder if any other Experts have any tips!

Emma

Hi Emma!

I’m trying to measure a solute between 5-25 micrograms. I will definitely consider your method!

Thank you for your help!
Funnyturtle79

wow thanks, Emma, I got to this forum and was surprised how helpful people are here. it is worthy of respect.