luca turin

[piranha]

as usual when i have a new obsession, i do a huge amount of skim-reading to learn things about a field by osmosis. wondering how smell actually works, i came across the name of luca turin who appears to be a maverick biophysicist with the controversial idea that our nose determines smell not by the shape of molecules, but by the vibrations of their electron bonds (if i got this right; i haven't yet read his first-hand writings on this). apparently mr turin is also a "nose" in the world of perfumery, whose nose is very good at detecting whatever it is that noses detect, be it shape or vibration. he can also write, he's witty, and he has a blog, which i think those of you who love writing up BPAL reviews might enjoy:

It [Rive Gauche Pour Homme] is strikingly refined and understated in a field populated by loud and exuberantly hairy-chested fragrances.

Like an old roué who is cantankerous in the morning, fantastic over lunch and then needs a siesta, Cocktail delivers five minutes of damaged topnotes, ten minutes of classic green-chypre beauty before settling down to a creamy marron-glacé base of labdanum very much in the generic Patou style.

I almost liked Eau Bleue for its boldness anyway, but what decided me against it was my daughter spraying the couch with it in a failed bid to empty the bottle. Three days later, it reminds me of the story of the family in Kirkuk who was visited by Saddam Hussein in his heyday, and who cremated the sofa after he left to be rid of the smell of his aftershave.

it's syndicated as luca_turin. mr turin seems to be a fascinating guy. some of his life is told by chandler burr in the emperor of scent: a story of obsession, perfume, and the last mystery of the senses, which sounds like a rolicking read. he himself has a book coming out next year, in which he explains his theory for the layperson: The Secret of Scent, ISBN 0571215378.

Comments

[aquaeri.livejournal.com]

Did you ever read this lj entry of mine (http://www.livejournal.com/users/aquaeri/7199.html)? It's from a completely different angle, being the kind of geek I am.

As far as I understand chemistry/molecular biology, what is called "molecular shape" includes things that would amount to electron bond behaviour. I'm not sure what Luca Turin is trying to distinguish with his claims.

[jinian.livejournal.com]

Good post, thanks for the link. And thanks very much for the blog pointer, pleonastic.

As I understand Turin's argument (from Emperor of the Senses, which is indeed a great read), bond vibration is distinct from molecular shape in that very different molecules can work out to very similar frequencies, which then smell the same to him and others that he's tested. Also, your post said something about 1000 receptors/signals on olfactory nerves, which seems to be a common number; Turin points out that we can smell just about everything, well in excess of that number. Of course, we could be receiving some combination of the receptors' signals, but that goes a bit against the very specific enzyme-substrate model that all my meager smell-attribution biology has used so far. Turin may not be totally right, but it really sounds like he deserves more attention than he's gotten to date.

[jinian.livejournal.com]

(I mean, Emperor of Scent. What an odd thinko.)

[nex0s.livejournal.com]

he sounds *marvelous*

[runs off to friend the blog]

n.

[pir-anha.livejournal.com]

no, i completely missed that (not due to filtering, just sometimes i get behind and don't fully catch up). thanks for pointing it out specifically!

i am as yet too uneducated on it to comment, however. :)

[aquaeri.livejournal.com]

I think I'll make sense of smell and opsins a bit of a side line in my research so I can surreptitiously pick up and pass on trivia.

I already have a weird research history connection with sense of smell. I studied the Major Histocompatibility Complex, which are a bunch of immune system genes. They're almost too diverse to be explained by normal evolutionary processes. So one of the sniggered-about (scientists are as prone to this as the rest of us) corners of MHC research is our ability to smell MHC types.

Mice can definitely smell MHC types, and female mice choose to mate with male mice who have different MHC types from themselves. Once they're pregnant, they set up a nest with other females who have similar MHC types as themselves to share the childrearing. (this has been corrected for the expected correlation between blood relatives and MHC types, although the selective advantage is probably that the nest is one of close relatives.)

Things get particularly sniggery when we get to humans, but there is limited evidence that humans do tend to choose sexual partners with different MHC types than themselves. And that women on the pill (which simulates pregnancy) prefer MHC types more like their own.

[aquaeri.livejournal.com]

I'm prepared to have an open mind on this; I really don't know enough about how the receptors are meant to work, although it is my understanding that there's a lot of combinatorics in the brain, processing the signals.

I'm pretty sure that for stuff like this, the specific enzyme-substrate model doesn't work. For example, there's no particular chemical commonalities between things that taste sweet, or things that taste bitter. (In fact, as you probably know, some artificial sweetners taste bitter to some people). We're just starting to get some info about the taste receptors, and from what I remember, in fact the sweet and bitter receptors are closely related evolutionarily (which means hundreds of millions of years :-) ).

Basically, as someone who is interested in this (both smell and taste) evolutionarily and molecularly, it's a great time to be around because we're just starting to get the data needed to have any clue what might be going on.

I'll put Emperor of Scent on my to-read list.

[lorres.livejournal.com]

Hairy chested fragrances indeed! Thanks for giving us the gems from his writing.

[eub.livejournal.com]

How pleasing. Thanks.