Worms are Economists Too!

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It sounds absurd to equate simple organism behaviors to humans.  However, nature is miserly and always adopts (jury-rigs) (very, very) old biological systems to more complex organisms – like us.   This is true of basic behavioral and nervous systems. The article below details some of these.

In addition, all animals face the same challenges of energy burgeting and movement in a three-dimensional world and social interactions.  So looking at the simplest living things can give us clues to biologically universal laws and processes – maybe.  But we are all looking for simplifying models of behavior – and energy (economics).

So here is a fundamental piece of neuroeconomics field work!  Excerpts below.  Our comments are in (…).

Dine Or Dash? Genes Help Decide When To Look For New Food

For worms, choosing when to search for a new dinner spot depends on many factors, both internal and external:

  • how hungry they are (drive)
  •  how much oxygen is in the air (resources or economy)
  • how many other worms are around. (social factors) 

A new study demonstrates this all-important decision is also influenced by the worm’s genetic make-up. 

In the simple Caenorhabditis elegans nematode, the researchers found that:

  • natural variations in several genes influence how quickly a worm will leave a lawn of bacteria
  • on which it’s feeding
  • One of the genes, called tyra-3, produces a receptor activated by adrenaline—a chemical messenger involved in the ‘fight-or-flight’ response.

“What’s encouraging to us about this story is that molecules related to adrenaline are implicated in arousal systems and in decision-making across a lot of different animals, including humans.”

These parallels between diverse species suggest that aspects of our decision-making abilities have ancient evolutionary roots. 

“The worms need to somehow evaluate a whole spectrum of conditions to decide whether they want to try this food source or go out and look for a better one,” (Sounds like classical economic scenario to us)

“Behavior includes the action of genes, their function in neurons, and the neurons’ assembly into circuits.  Studying C. elegans gives you an exceptional ability to make connections between those levels.”

Over the past decade, her lab has probed several of these levels. In 2004, they reported that C. elegans: 

  • sense precise oxygen concentrations in soil, which helps steer them toward their favorite meal: oxygen-consuming bacteria
  • that odor-sensing neurons can switch on other cells that control crawling and turning
  • the new study, investigating how genetic tweaks can change a worm’s behavior in particular circumstances.

In the end, the researchers could pinpoint particular genetic blips associated with moving away from a food source.  One of those blips crops up in a gene called npr-1, which had already been associated with foraging behaviors and immunity in the worm.

In these neurons, external cues, such as oxygen levels, can be integrated with internal states, such as hunger.  The findings show that particular genetic variants lead to specific behaviors in the real world—but how, exactly, they do this is still mysterious.

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