Jellyfish may be crazy, but they can do surprisingly complex things with a simple nervous system. Now, by tinkering with jellyfish genes, researchers have devised ways to spy on the internal workings of animals.
In a new study, researchers used jellyfish seeds to create models. Clytia hemisphaerica, A transparent umbrella-shaped jellyfish with a tubular mouth in the center. Small jellyfish grow to only 0.4 inches (1 centimeter) in diameter. That is, the team can place the entire jellyfish under a microscope and observe it in its entirety. Nervous system All at once.
While Human brain Jellyfish act as a centralized control center for the body, and the nervous system does not have such a structure. Instead, many jellyfish have a diffuse “net” of nerves that radiate symmetrically from the center of the body. In addition, there is a nerve ring that runs around the bottom of the bell, which is the half-moon shaped part of the jellyfish. According to the journal’s 2013 report, some jellyfish have no neural network, only neural rings. Current biology, However C. hemisphaerica It has both of these structures.
The big question is how these little jellyfish collaborate without centralized control of movement. For example, how do a chubby creature steal a shrimp from a water column, fold it in half and pull the snack towards a tubular mouth?
I put a special glowing protein in the place where there is a jellyfish genome Lead author Brandon Weissboard said that it only lights up in active neurons. biology Biotechnology, California Institute of Technology. “When neurons are active, the amount of calcium [inside the neurons] As it rises, GCaMP becomes more fluorescent. This means that neural activity appears to be flashing, “Weissbourd told Live Science in an email.
However, jellyfish glow naturally.Therefore, in order to see the designed blinking more clearly, the team CRISPR He said they continued to surpass the GCaMP they inserted to cut out specific genes that make different fluorescent proteins.
Now that the jellyfish has transformed into a miniature light show, the team has conducted some experiments to see which neurons light up during typical feeding behavior. They found that a group of neurons near the shrimp suddenly turned on when the jellyfish got caught in a brine shrimp or came into contact with the team’s “shrimp extract.”
Related: Strange animal facts
This activation did not spread to the entire jellyfish. Like a stone dropped in a puddle sending ripples over its entire surface. Rather, in response to shrimp snacks, only neurons within the well-defined wedge-shaped area of the bell were lit. The wedge of this active neuron was shaped like a single pizza slice in a circular pie. According to the statement.. The team found that the neuron closest to the shrimp was lit first, and then a large number of strobe lights were illuminating the rest of the slice.
So, for example, if a shrimp is placed on the far end “crust” of a pizza slice, the crust will light first, then the rest of the slice. This spillover was consistent with the jellyfish being folded in the corner of the bell to bring the shrimp to the mouth.
The team did not expect to observe this level of tissue within a seemingly unstructured neural network, Weissboard said. “The discovery of the unique structure in the network was certainly amazing,” he said.
In the future, the team plans to investigate how jellyfish control all behaviors, not just feeding, and plans to study different types of jellyfish that behave differently. doing. C. hemisphaericaSaid Weissboard. For example, some jellyfish may behave as follows: C. hemisphaericaInstead, some people use long-distance mouthpieces to pick food from their tentacles. “Given the diversity of jellyfish and many of them being small and transparent, I think we can provide an exciting platform for understanding how the nervous system will evolve in the future.”
These studies of jellyfish strobes can also shed light on the basic principles that govern all nervous systems, from the simplest to the most complex. “The idea is to develop an experimental and theoretical approach to understanding how the simpler nervous system works as a step towards understanding the human brain. This is an order of magnitude more complex. Weissbourd told Live Science.
The team published their findings in the journal on November 24th. cell..
Originally published on Live Science.
Scientists have inserted a disco “strobe light” into a jellyfish to see how it works without a brain.
Source link Scientists have inserted a disco “strobe light” into a jellyfish to see how it works without a brain.