Does Laughter Cause Gene Expression?

( – promoted by buhdydharma )

I want to know: Does laughter cause gene expression?  This is a question I have never heard asked.  If there is a psychologist or neuroscientist in the audience who knows if this question has ever been asked, I want to know that, also.  The answer is certainly, Yes.  Of course, there are genes constantly activated by everything we do.  But are there specific genes associated with laughter?  This is not a subtle question, such as the difference between humor and laughter.  I am talking about Hee-Haw, robust, in yer face, I can’t stop laughing, lol catz!

Minimally, one can assume that there will be genes activated that are associated with learning and memory.  One might also assume there are genes activated associated with emotions, probably both positive and negative emotions, as laughter typically pits these valences against one another.  What are the genes that are consistently activated by laughter?

Are the same genes activated in chimps and in humans?  Chimps (when tickled) laugh differently than us, in both directions, inwardly and outwardly, inspirations and expirations: ooh-heh, ooh-heh.  Humans only laugh with outward expirations: heh-heh-heh-heh-surface from laughing for a big suck of air that is not laughter, followed by more laughter–hah-hah-hah.  This significant difference in “laughing,” and it certainly appears to be “laughing” in tickled chimps, as tickling is a delightful (positive) loss of control (negative) over being touched, presumably owes to differential evolution of speech apparatus, e.g., the innervation of intercostal muscles, lungs, rhythm generators, etc.  There might be differences, based on that.  But aside from physiological and neurological differences in breathing patterns associated with an evolved ability and propensity to speak human language, are there humor-specific genes in primates?  In mammals more generally?  Rats appear to “laugh” also, when tickled.  At least, they emit a particular frequency of vocalizations when tickled.  Is it the same as human laughter?

It seems like a very important question for our decidedly social species.  Is laughter specifically encoded in our DNA?  How widespread is it, phylogenetically speaking?  I hate to even ask, because with current technology, e.g., in situ hybridization of RNA probes on brain tissue, we’d probably have to induce a paroxysm of joy and then kill someone to find out.

Update:

http://www.ncbi.nlm.nih.gov/pu…

Huh.  This paper provides evidence that laughter upregulates a receptor gene in the blood, so surely it must do things in brain, as well.  Of course, it would be nice to know which ones.