You must remember this...

Nicholas Wade reports in today's Science Times on the work of Dr. Gero Miesenböck's lab. Its carnival-barker headline cries: Researchers Create Artificial Memories in the Brain of a Fruitfly. If one reads the article, its claims are a little more circumspect but no less impressive. The lab identified dopamine producing neurons in the nervous system of flies that seem to perpetuate shock avoidance behaviors. These cells do their work by converging on a second class of neurons - Kenyon cells - which receive information about stimuli from the fly's antennae. Typically the fly can be conditioned to learn avoidance of a stimulus other than the shock - like a particular odor perceived by the antennae or a flash of light - through conditioning. Conditioning creates an association between the shock and the new stimulus which results in the fly behaving to the light or odor as it would naturally behave to a shock - by avoiding it. Miesenböck and friends genetically manipulated the flies so that their Kenyon cells would automatically respond to the light flash as though it were a shock without ever having been conditioned to do so. Then they then tested their manipulation by doing a typical conditioning experiment through which the flies would learn to associate a smell with the light, reacting with avoidance.

When lasting learning is accomplished, exposure to certain stimuli perpetuates structural or chemical changes in neurons. Any time cell structure is altered, a gene must first be induced to create a chemical template that leads to the assembly of a protein. Proteins are the basic units of cellular components, whether structural or chemical. The presence of these proteins, then result in the proper change in the cell which might be the production of a neurotransmitter, or the insertion or removal of a particular type of channel into a neuron membrane. The researchers in this case, altered the gene directly, creating a fly that never had to learn to respond to a light flash as though it were a shock. Through multiple experiments like these they hope to map the neural circuits that associate stimuli with behavior and lay bare the circuitry through which creatures learn.

It all makes me think of this little ditty, sung by Sam in Casablanca (words and music by Herman Hupfeld). It seems today to typify associative learning. Now, if we decide it, flies must remember this. No fundamental rules apply...

This day and age we're living in
Gives cause for apprehension
With speed and new invention
And things like fourth dimension.

Yet we get a trifle weary
With Mr. Einstein's theory.
So we must get down to earth at times
Relax relieve the tension

And no matter what the progress
Or what may yet be proved
The simple facts of life are such
They cannot be removed.]

You must remember this
A kiss is just a kiss, a sigh is just a sigh.
The fundamental things apply
As time goes by.

And when two lovers woo
They still say, "I love you."
On that you can rely
No matter what the future brings
As time goes by.

Moonlight and love songs
Never out of date.
Hearts full of passion
Jealousy and hate.
Woman needs man
And man must have his mate
That no one can deny.

It's still the same old story
A fight for love and glory
A case of do or die.
The world will always welcome lovers
As time goes by.

Oh yes, the world will always welcome lovers
As time goes by.