New study explores plants under anaesthesia

new Delhi: Anesthesia is a condition of controlled, temporary loss of sensation or awareness that is induced for medical purposes in humans. But can plants also be given anesthesia? A recent study has explored this possibility.

The study was published in the journal ‘Scientific Reports’. The drug has a wide repertoire of anesthetics, its medicine allows patients to better tolerate painful treatments or even sleep through them. As early as 1842, ether was used for dentistry for the first time in New York. Since then, this anesthetic has served as one of the main anesthetics worldwide for more than 100 years.

Remarkably, anesthetization is also possible in plants. Claude Bernard proved in 1878 that the touch-sensitive plant Mimosa pudica did not react to touch under the influence of ether by closing its leaves. They concluded that plants and animals must have a common biological essence that is disturbed by anesthetics.

Ether anesthetics were used during surgery, childbirth and palliative treatment to relieve patients’ pain. However, the exact mechanism of action has never been clarified. Even with modern anesthetics, it is often unclear how and where they work. One reason for this is certainly because humans are a very delicate research topic.

This is where plant researchers from the Julius-Maximilians-Universitat (JMU) Würzburg in Bavaria, Germany, stepped in. Professor Rainer Heydrich’s team has been researching the Venus flytrap for more than ten years. They have already acquired many important information about the life of this carnivorous plant.

“Unlike most other plants, the Venus flytrap is particularly sensitive to touch. In response to such stimuli, electrical impulses are triggered and transmitted very quickly to capture the animal’s prey, Heydrich explained.

The flytrap’s electrical impulses (action potentials, APs) are similar to those of our nervous system. It is true that plants do not have a separate nervous system. But they do transmit electrical information in their conductive tissue, for example, to close the trap at lightning speed: “In 2016, we were able to show that the human-like Venus flytrap can perceive not only touch but can also count and remember. The AP has thrown it out,” the Würzburg professor explained. “So it made sense to test whether ether affects the carnivorous plant’s sense of touch.”

However, before the plant could be anesthetized, some difficult obstacles had to be overcome in order to be able to use the highly explosive ether gas.

“Deaths that resulted from explosions, unfortunately, occurred repeatedly in the medical use of ether. So we had an explosion-protected device built so that we could work safely without blowing up the whole institution,” said Dr. Sonke Scherzer Told with a smile.

In this way, the Würzburg researchers found that the Venus flytrap can be anesthetized like a human, and does not react to touch in the meantime. Examination of trap memory also revealed that the trap could “not remember” being touched during anaesthesia. Thus, its response does not differ from one patient, as Heydrick’s team reported in the study.

“Things got really exciting, however, when we learned that anesthetic traps can locally perceive touch, but cannot transmit it,” said Sonke Scherzer, the paper’s first author.

Each touch of the sensory hair releases the signal molecule calcium in the Venus flytrap. This molecule also played a decisive role in the transmission of stimuli in humans.

In the plant, however, the JMU researchers were able to make the calcium signal visible by expressing a genetically encoded calcium sensor. They found that the calcium signal is still generated after a touch in the sensory hairs of sensitized plants, but it no longer leaves this tactile sensor. Therefore, the ether inhibited the transmission of stimuli.
“Now we finally know in which tissue the ether acts,” said Sonke Scherzer. But to understand the exact mechanism of action of anesthesia, the Würzburg researchers studied these hairs in detail and found that only full-grown trap hairs trigger a strong calcium signal when touched. On the other hand, immature traps do not have this signal and therefore cannot capture any prey.

“Now we have seen how these two developmental stages differ and have come across an interesting gene that is found specifically in the hairs of the adult tentacles,” said Rainer Heydrich. This gene encodes a glutamate receptor, which is apparently responsible for the rapid transmission of stimuli. These receptors sense the neurotransmitter glutamate and are also found in humans, where they are involved in the transmission of stimuli across synapses.

Here, the plant researchers received support from Professor Manfred Heckmann, a specialist in animal glutamate receptors at JMU Würzburg. “Indeed, we see calcium signals when we externally stimulate the trap with glutamate,” Heckman said. “However, this response does not occur in anesthetized traps or immature traps without the glutamate receptor. Thus, the glutamate receptor appears to be a potential target in ether anesthesia. When this receptor is blocked, excitation transmission also stops. “

“We now need to find out what animal and plant glutamate receptors have in common and how they differ,” Heckman outlined the ongoing experimental research.

“With this paper, we show that the Venus flytrap can serve as a study object not only for plant research, but also for medicine. With it, the mechanism of action of drugs can be determined without conducting animal experiments.” It may be possible to investigate.” Scherzer excluded the possibility. (ANI)

First published:February 21, 2022, 11:30 PM

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