Tuesday, November 23, 2010

purple pain and a gene called 'straightjacket'

Dr. Kevin Mitchell, a neuroscientist at Smurfit Institute of Genetics, University of Dublin, posted at his excellent blog Wiring the Brain about a weird, interesting study* that points to a possible genetic explanation of synaesthesia** (e.g., hearing a word and experiencing the color red). The authors were studying pain mechanisms in fruit flies (turns out the mechanisms are similar to us mammals, whuddathunk?). Once they identified a particular gene they dubbed straightjacket*** which is "involved in modulating neurotransmission," they systematically deleted it in test flies and discovered that the test subjects**** no longer processed the pain stimuli, even though the pain stimuli was following the pathway. In Mitchell's words:

Somehow, deletion of CACNA2D3 alters connectivity within the thalamus or from thalamus to cortex in a way that precludes transmission of the signal to the pain matrix areas. This is where the story really gets interesting. While they did not observe responses of the pain matrix areas in response to painful stimuli, they did observe something very unexpected – responses of the visual and auditory areas of the cortex! What’s more, they observed similar responses to tactile stimuli administered to the whiskers. Whatever is going on clearly affects more than just the pain circuitry (emphasis added).

So, if I understand this, they turned off the ability to recognize pain, but when they administered painful stimuli (heat), the test subjects had visual, auditory, and tactile experiences. Imagine putting a flame to your hand and seeing purple. Pretty frikkin awesome. Dr. Mitchell's post does more justice to this complex study, I just thought it was awesome.


*Geez! Take a look at the author list of the publication. Do you have a place for 12th author on YOUR CV?

**FYI: Synaesthesia is NOT the same thing as sound symbolism, necessarily. True synaesthesia is a rare phenomenon that appears to have biophysical roots. Sound symbolism is mostly hippie-dippy bullshit exploited by marketing professionals to sell stuff.

***I have no clue why they called it this, but it's a hell of a lot more awesome than CACNA2D3.

****There were multiple studies referenced, some involving fruit flies, some involving mice, and it wasn't clear to me which evidence came from which studies, so I have chosen to use the cover term "test subjects."

ResearchBlogging.org
Neely GG, Hess A, Costigan M, Keene AC, Goulas S, Langeslag M, Griffin RS, Belfer I, Dai F, Smith SB, Diatchenko L, Gupta V, Xia CP, Amann S, Kreitz S, Heindl-Erdmann C, Wolz S, Ly CV, Arora S, Sarangi R, Dan D, Novatchkova M, Rosenzweig M, Gibson DG, Truong D, Schramek D, Zoranovic T, Cronin SJ, Angjeli B, Brune K, Dietzl G, Maixner W, Meixner A, Thomas W, Pospisilik JA, Alenius M, Kress M, Subramaniam S, Garrity PA, Bellen HJ, Woolf CJ, & Penninger JM (2010). A Genome-wide Drosophila Screen for Heat Nociception Identifies α2δ3 as an Evolutionarily Conserved Pain Gene. Cell, 143 (4), 628-38 PMID: 21074052

4 comments:

Andrew said...

It's also great how the original people that identified the gene straightjacket spelled it wrong (should be straitjacket), but now the typo is immortalized in Drosophila gene nomenclature.

Alon said...

Re: note 2, there seems to be at least some evidence for phonetic symbolism, according to MYL (I'll confess I haven't got around to reading the original article).

Chris said...

@Andrew: I wonder if there's a difference in spelling between the US and UK?

@Alon: I'm willing to admit that there is some tentative evidence for something akin to sound symbolism, and the work on synaesthesia is part of that, sure. My snarky little comment was directed more at the type of stuff you see on branding websites about how to name anew product based on "strong" sounds and such like that.

Andrew said...

I don't think it's a US/UK thing - I'm actually American, same as the people who first discovered straightjacket (sic). Though it seems straightjacket is given as an alternative spelling in the dictionary. Of course, the meaning explains the spelling - a straitjacket is tight and narrow to restrain the wearer, rather than being a "straight" jacket. I guess you could call straightjacket an eggcorn.