Monday, May 4, 2009

Sounding the Alarm

How many blog posts can one person write about slime mold? I've already written at least two, but here's another - this time, a lesson from this humble little organism about how to respond to pandemics.

The slime mold, more properly known as Dictyostelium discoideum, begins life as a single-celled amoeba. A colony of Dicty (as they are affectionately known in the microbiology community) is quite happy to exist as single cells as long as there is enough food. But when food becomes scarce the colony goes through an amazing sequence of changes culminating in the production of a multi-cellular organism, as shown in the following lifecycle diagram.


When the colony moves from the region encased by the box along the arrow labeled "aggregation," it does so because some of the amoeba have started to send out distress signals.

The lack of food, or "starvation," as it's described in the diagram, converts some of the amoeba into little town-criers who begin to send out chemical signals that let the colony know that the food supply is disappearing.

These chemical signals are actually periodic pulses of a common signaling molecule known as cyclic adenosine monophosphate, or cAMP.

So what does all this have to do with flu epidemics? Some have questioned whether the media and bloggers (not to mention people on twitter) are providing useful information or merely adding to the hype when they publish or broadcast, or merely forward, information. Others have asked if people are over-reacting and questioned whether adding one's voice to the many that are providing information is responsible.

I say, take a look at the slime mold to see what a very resilient social organism does. When the colony is in danger, the first reaction is to sound the alarm. Send out a notice that says to the others, "come this way, form yourselves into an aggregate, and don't ask questions. What we are asking you to do will save your life."

Nothing in the cAMP signal tells those little amoeba what is in store for them. They do not know that the process they are embarking on will turn them into a slug!

They also do not know that this socially-driven process will, in the long run, save them -- in their case, from starvation.

And it is the same with us. We have appointed some among us as messengers. We look to them for information and we listen and read what they provide to us. We make our decisions about where we go and what we do in response to this uncertain situation using this information.

We are very lucky, when you think about it. Imagine what the world was like for those generations that came before us who didn't understand the basis of disease, didn't know what they should be afraid of. During the dark years of the bubonic plague, nobody knew that the danger was in the very air they were breathing.

Now we know, and it is good to have as much information as possible. We are smart people and we can be trusted to make decisions about our health and that of our family if we are given all the information.

So, I say, tell us what you know and don't worry about spreading fear. We have nothing to fear, really, but ignorance.

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