Nav: Home

Calcium dynamics regulating the timing of decision-making in C. elegans

May 22, 2017

Animals, like humans, make various decisions based on information from the environment: for example, what to eat, where to go, and who to mate. Such decision-making is thought to be characterized by (1) distinct choice of one option based on gradually changing and/or confusing environmental information and (2) the choice is quick when the information is clear but slow when unclear. Researches on decision-making from neurobiological aspect have been performed by using monkeys and rodents, although the details of the mechanisms have been unclear because their brain consists of more than hundreds of millions of nerve cells.

Tanimoto, Yamazoe-Umemoto and colleagues discovered that a tiny roundworm with only 302 nerve cells do "decision-making" during escape response from the aversive odor. Moreover, they found that the worms make decisions by calculating mathematical integration of the odor's information. First, the research team set up a robotic microscope that simultaneously measures the nerve activity and behavior of a worm in the virtual odor space. The nerve cell's activity was measured via concentration of calcium ion in the cell, and the team analyzed the changes in calcium concentration using a mathematical model.

Using the robotic microscope system, they found that, when a worm is trying to find out the favorable direction to move away from the odor, the calcium concentration in a nerve cell raises slowly according to the mathematical integration of the amount of decrease in the odor concentration, that is, it adds up for a certain period of time. And when the calcium concentration reaches to a certain value, the worm choose the direction as a "deliberate" decision. In contrast, when a worm happens to move in the unfavorable direction where the aversive odor increases, the calcium in another nerve cell raises rapidly according to the mathematical differentiation of the odor concentration for a rapid "reflex"-like response. Furthermore they found genes that enable the integration and/or differentiation.

In researches using the more complex animals, it is known that certain nerve cells in the brain integrate information and make a decision when reaching a certain level, which likely occurs also in humans. The research team's result showed that, surprisingly, the worm's nerve cell also integrates information for decision-making. A human gene similar to the one found in worms may also be involved in our decision-making.
-end-


Osaka University

Related Nerve Cells Articles:

Unique fingerprint: What makes nerve cells unmistakable?
Protein variations that result from the process of alternative splicing control the identity and function of nerve cells in the brain.
Ragweed compounds could protect nerve cells from Alzheimer's
As spring arrives in the northern hemisphere, many people are cursing ragweed, a primary culprit in seasonal allergies.
Fooling nerve cells into acting normal
In a new study, scientists at the University of Missouri have discovered that a neuron's own electrical signal, or voltage, can indicate whether the neuron is functioning normally.
How nerve cells control misfolded proteins
Researchers have identified a protein complex that marks misfolded proteins, stops them from interacting with other proteins in the cell and directs them towards disposal.
The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.
Research confirms nerve cells made from skin cells are a valid lab model for studying disease
Researchers from the Salk Institute, along with collaborators at Stanford University and Baylor College of Medicine, have shown that cells from mice that have been induced to grow into nerve cells using a previously published method have molecular signatures matching neurons that developed naturally in the brain.
Bees can count with just four nerve cells in their brains
Bees can solve seemingly clever counting tasks with very small numbers of nerve cells in their brains, according to researchers at Queen Mary University of London.
Nerve cells in the human brain can 'count'
How do we know if we're looking at three apples or four?
How rabies virus moves through nerve cells, and how it might be stopped
Researchers found that the rabies virus travels through neurons differently than other neuron-invading viruses, and that its journey can be stopped by a drug commonly used to treat amoebic dysentery.
Direct conversion of non-neuronal cells into nerve cells
Researchers of the Mainz University Medical Center discovered that on the way to becoming neurons pericytes need to go through a neural stem cell-like state.
More Nerve Cells News and Nerve Cells Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#542 Climate Doomsday
Have you heard? Climate change. We did it. And it's bad. It's going to be worse. We are already suffering the effects of it in many ways. How should we TALK about the dangers we are facing, though? Should we get people good and scared? Or give them hope? Or both? Host Bethany Brookshire talks with David Wallace-Wells and Sheril Kirschenbaum to find out. This episode is hosted by Bethany Brookshire, science writer from Science News. Related links: Why Climate Disasters Might Not Boost Public Engagement on Climate Change on The New York Times by Andrew Revkin The other kind...
Now Playing: Radiolab

An Announcement from Radiolab