To us, memory is almost instantly associated with the brain-and rightly so. It is where memories are formed, changed, and recalled. Any stimulus creates a series of neuron activity. In the case of memory recollection, specific groups of neurons are reactivated in response to a specific stimulus. However, the plasticity of the brain also means the synapses involved can be changed, removed, or added to in these pathways. But what about organisms without brains? Are they capable of forming and recalling memories like animals? Monica Gagliano from the University of Western Australia thinks she may have found an organism that can.
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| Photo by blickwinkel, Alamy |
Mimosa pudica is a plant commonly known for its highly-sensitive leaves. The slightest touch or movement can trigger them to curl together. Gagliano wanted to investigate this phenomenon further to see if plants could use memory to change their behavior. To do this, she built a device that dropped potted plants roughly six inches onto a piece of foam. The height was not nearly enough to cause physical harm, yet the M. pudica were still disturbed enough to close their leaves. She repeated the drop 60 times in a row for each of her plants. Surprisingly, by the end of the 60 drops, M. pudica kept their leaves completely open. And they continued to show this behavior after waiting as many as 28 days between drop series. It is also interesting to note that while the vertical drop would no longer signal M. pudica leaves to close, moving the plants abruptly in other directions would.
These results hint at the possibility that memory retention may not only be unique to the neural pathways found in the brain. Plants do not have brains, but they “‘do possess a sophisticated… signaling network.’” Gagliano has been dismissed by some biologists who are skeptical about the idea of intelligent plants. Others do not like the idea of further blurring the line between plant and animal. What do you think? To me, since what we know is always changing in the scientific community, I’m interested to see if anyone else attempts to elaborate on these new findings.
Posted by "Meagan Gustafson" (2)
This was a very fascinating blog post. It's giving light to how plants possess such a complex signaling network that it seems as though it can mimic memory as seen in animals. As you mentioned, plants do not have a brain so they would not remember to curl their leaves. The phenomenon in the experiment must be a programmed response to the change in their environment.
ReplyDeletePosted by Lauren Shone
I can't help but think of the Mimosa Pudica plants (commonly referred to as "shame plants" we have here at the Durfee Conservatory on campus. It is fascinating to see a plant that can physically respond to a stimulus as fast as you or I. I do believe the development of some type of plant "brain" could be possible. Evolutionary biologists have theorized how the brains might have developed in animals; the theory essentially was that in animals, the nervous system became more centralized over many generations. Perhaps if plants' signaling systems became more centralized and sophisticated in their reactions to stimuli, a plant "brain" could form eventually (although it would likely take on a new name).
ReplyDelete-David Frykenberg
Looking at this from an evolutionary perspective is definitely part of the reason I was so intrigued by it. While some people don't like the idea of blurring the line between animal and plant, I think it makes sense. Just like how the "traits of living things" become blurred when talking about viruses, etc. I'm really interested to see if we begin to gain any more knowledge on just how extensive/sophisticated plant signaling networks are.
DeletePosted by "Meagan Gustafson"
This is a very interesting article; reading about the behavior of this plant reminds me of the venus fly trap. Similarly movement wise, the venus fly trap has modified hairs that act as mechanoreceptors.These hairs transfer mechanical energy into electrical energy. This network allows the two modified leaves to close when a stimulus is sensed. I wonder is the type of network found in a venus fly trap is similar to the one referenced in the blow above. It would be interesting to read more about the physiology behind Mimosa pudica.
ReplyDelete-Elise Babula
I wonder if this experiment has been performed with other plants? I can't think of any off the top of my head that would be able to perform a quick and measurable action, other than possibly a venus flytrap. Still it would be very interesting to explore the possibility of this phenomenon of memory recollection in plants. I feel that the plant possibly could have stayed open because of the amount of energy needed to open and close its leaves. Because plants cannot store an immense amount of energy at once, the action may not have been possible for any longer.
ReplyDeletePosted by Isaac Collibee
I was thinking this too, at first. I figured it could have just been centered around energy allocation or desensitization to movement in general. But the researcher who performed this experiment also shook the plants in a horizontal fashion directly after the series of vertical drops-and the pants closed their leaves! That is what convinced me that there could be some substance to the results she got. I want to see if anyone else attempts this with other species of plants or investigates the behaviors of this species any further.
DeletePosted by "Meagan Gustafson"
The Idea of plant communication is very interesting to me. Plants do not have advanced neural networks or a brain so it is inferred that the “communication” is done through environmental factors. Although it is different than plants slime mold can have a similar method of communication. Using nutrient pockets designed to represent Tokyo, researchers had a slime mold grow to see the efficiency of the slime mold. The slime mold then grew its nutrient pathway network to be just like the Tokyo subway networks. I found that to be an interesting application to the communication of the slime mold. Using organisms like slime molds to create the most efficient pathways may be a better way to city plan.
ReplyDeletePosted by John Mariano
I find this post fascinating! I grew up in Puerto Rico and we used to have these plants all around our backyard, over there we call them "morivivi" which basically means "I died, I lived". I used to touch them all the time because it was fun to see them close down and a couple of minutes later open up. As much as I loved those plants it never occurred to me to look into the aspect that makes it happen. It's amazing that someone is trying to figure out the reason behind it.
ReplyDeletePosted by Genesis Figueroa
This is such a fascinating topic, one of my friends has a sensitive plant and I was mesmerized by its ability to open and close. I had never considered that it's response could have been the result of a sophisticated signaling or memory pathway. I wonder if human signaling and memory pathways are somehow evolutionarily related to this mechanism since some of the first life on earth was plant life, such as algae.
ReplyDeletePosted by Kayla Rosiello
This post was very interesting to read. I believe that if humans and animals can have memory retention then why not plants? Even though plants don't have brains, I am sure there are other ways which they retain information. I would love to see this done on other types of plants to see the outcome and compare results. These plants are fascinating and I would love if more people were to spend their time researching them!
ReplyDelete-Posted by Sophie DeRepentigny