Talk:Odotope theory

Remove?
This article seems to cite no scientific articles or review articles. Adrian (1950) first proposed the term odotopy. I recommend that this article be deleted if references cannot be provided. unsigned comment by User:DrEricH


 * I just checked Adrian, 1950, btw the article is called SENSORY DISCRIMINATION: With Some Recent Evidence from the Olfactory Organ. I did not find any reference to odotopy in Adrian's article. I don't see why you recommend deletion of this article and I think you are rash with your recommendation. I put the original reference in the reference section, so I think you should be satisfied, anyways. Ben T/C 13:16, 6 February 2009 (UTC)

Infinite?
Someone is encouraged to check the math underlying the claim that a finite number of receptors can 'theoretically' detect an infinite number of smells. Despite combinatorial explosion (which is huge), the number of combinations of a finite number of receptors is finite (unless the sequence of detection is important AND the same receptor could be triggered a different number of times for different odors). unsigned comment by User:DoNNNald.


 * It is correct to say receptors can theoretically can detect an infinite number of odorants because of the different affinities of each receptor to odorants, although the actual number is a function of training. An often cited estimation of numbers of distinguishable odors which puts the number of distinguishable odors at 10,000 is a paper by either Axel or Buck or both, I think from 1996. I don't know how they came up with this number. If we were talking about all or nothing reactions to odorants you would be right with your doubts about theoretical infinity of odor perceptions, however the picture is more complex (as you suggest in parenthesis). Each odorant molecule activates a lot of different odorant receptors, each with a different frequency (according to affinity). This is reflected in frequencies and intensities of activation of olfactory sensory neurons of each receptor type. Apart from this, there are more unresolved complexities lurking: possibly the sequence of activation is important, as could be the situation of activated olfactory neurons in the epitelium. As for the last, this could give information about e.g. the hydrophobicity and weight of odorants. There could be also an importance in the shape of the epithelium which possibly has a filter (or rather separator) function, though this is far from clear yet. These theoretical considerations are supported by opinions by odorant experts, such as perfumists (this is often given as argument in articles) who state that no two odors smell exactly the same. Do I make sense to you? Ben T/C 12:20, 6 February 2009 (UTC)


 * I just checked the reference for the estimation of 10,000 odors. I was surprised to learn that it is an article in Scientific American (The Molecular Logic of Smell, Axel 1995). According to google scholar it has 172 cites. I think the actual number is not that important it is more that there are many odors. Ben T/C 15:16, 6 February 2009 (UTC)

Weak-Shape Theory
I never heard that name before and would like to see a reference to it. Ben T/C 16:39, 6 February 2009 (UTC)