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I have seen a couple of talks about the neuroscience of olfaction from which it seemed that these preferences are almost completely *not* hard-wired: one can
learn neurally to love or hate the vast majority of odors/aromas. The easiest way to do this is negatively by presenting an odorant and then inducing vomiting—works really effectively to create aversion, even though the odorant is merely an “accident.” We
owe to this plasticity, perhaps, the love of Limburger cheese, which I have not yet had the “privilege” to try. Here’s the nutritional info:
28 grams of Limburger contains 5 grams of saturated fat and 8 grams of total fat. 67 of the 92 calories in the 28 grams are from fat. So, love overcomes
hatred: the body’s love of fat overcomes smelly-feet odor (literally—it’s the same bacterium!)
While we’re on the topic, I saw a talk in which data were presented showing the response of each of the ~800 odorant receptors to various odorants, and each
odorant had a pretty unique profile, even for chemically-similar entities. One can think of the sense of smell, then, as an 800-dimensional space, where each dimension is the response of a given type of olfactory receptor.
JPK
From: CCP4 bulletin board [mailto:[log in to unmask]] On Behalf Of Artem Evdokimov
Sent: Tuesday, January 26, 2016 8:46 AM
To: [log in to unmask]
Subject: Re: [ccp4bb] Best reducing agent
Sorry for the offtopic line of posts, but this may actually be entertaining to some.
That's exactly why I brought it up :)
To a percentage of the population, Durian smells unbelievably foul - and then again to others it smells great! I suspect that this is driven by smell receptor
polymorphism or something like that. Same with lutefisk - to many of us it smells like rotten fish (which it is, kind of) - but I have seen people eat it with all visible signs of enjoyment.
Then there's phenylthiocarbamide, propylthiouracil and other compouds of the thiourea class that taste bitter to 2/3 of people and to 1/3 they do not have a
taste at all, which in turn seems to govern our love for broccoli and other brassicate vegetables
Bell KI, Tepper BJ. Short-term vegetable intake by young children classified by 6-n-propylthoiuracil bitter-taste phenotype. Am J Clin Nutr. 2006 Jul;84(1):245-51.
They (maybe still do?) used to distribute small samples of the stuff to genetics lecture audiences because this phenomenon is governed by inheritable polymorphism
of TAS2R38 receptor. Arthur Fox from DuPont discovered this in the 1930-ies which gives me the opportunity to gleefuly quote an almost 100-year old paper:
Fox, A. The relationship between chemical constitution and taste. PNAS USA, 1932;18:115–20.
Also cool read: Genetics of Taste and Smell
Artem
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On Tue, Jan 26, 2016 at 5:23 AM, Harry Powell <[log in to unmask]>
wrote:
Hi
Durian is a real pleasure - I can get them locally and they are a huge treat!
On 26 Jan 2016, at 02:21, Artem Evdokimov wrote:
Not sure :(
Mercaptanes are pretty much all smelly (less so as they get large and less volatile). So are arsines and other fun reactive chemicals although I think mercaptanes
are so smelly to us because they are common byproducts of putrefaction and this is the case of evolution telling proto-man that eating this particular smelly animal carcass would be a jolly bad idea. Ditto the aptly named putrescine and cadaverine (and many
of the long-chain fishy amines in general). Those who evolved to recognize the smell as 'bad' lived, the others followed the cold merciless miracle of natural selection. Makes one wonder about lutefisk, durian fruit, and many of the nastier cheeses...
The headaches are real, though. Mine get bad enough to qualify as migraines.
Artem
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On Mon, Jan 25, 2016 at 9:15 PM, Keller, Jacob <[log in to unmask]>
wrote:
>BME gives Artem (and several people I know) wicked headaches, even at minimal exposure.
I have always wondered whether the headache or perhaps also the stinky smell itself comes from some
disulfide-bonded protein in the olfactory apparatus getting reduced. Also with glutaraldehyde—are the olfactory receptors getting cross-linked?
JPK
Harry
--
Dr Harry Powell, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH
Chairman of International Union of Crystallography Commission on Crystallographic Computing
Chairman of European Crystallographic Association SIG9 (Crystallographic Computing)