Friday, September 20, 2019

Olfactory Clues To Disease Discovery



Smells can be a great sign of danger, even when it comes from our own bodies. We've got here a story about a woman who smelled Parkinson's on her husband a good ten years before he was diagnosed. This spurred research into the subject, and we now have an idea of what the smell is and how it fits into the effects of the disease.

Tldr, it comes from the production of excess sebum, which contains chemicals known to be related to altered neurobiology associated with Parkinson's. The scent-sensitive woman who noticed it on her husband described it as earthy and musky.

Then there's the nick-of-time test for Maple Syrup Urine Disease. Although the disease can be verified with a blood test, symptoms could get so bad so fast that the time required for this testing becomes prohibitive. Luckily, it can also be identified by sweet-smelling urine, sweat and earwax.

Maple Syrup Urine Disease is a condition where the body can't break things down properly. If our body's natural defense system is inhibited so much that it can't break down the maple-syrup-molecule, for example, then we've got serious problems.

I am not a doctor so I don't know if this is the same smell/molecule, but Sotolon is the "maple syrup molecule." Other things could be exuding from the body, but this is a potent aroma compound, so it's easy to detect.

As a general rule, if you notice that you smell funny, it's something that should be checked out immediately. For example, fishy odor in the urine could be a sign of a urinary tract infection, and the smell comes from the bacteria living there (as opposed to the improper biotransformation of ingested molecules).


Post Script:
Then there's the cancer-smelling dogs, surely we've all heard of that. And for the record, if we interfaced with the world the way dogs do, with smell being way more important, and if we spent lots of time smelling all the things around us, including our own bodies, or those of our loved ones, we might notice these things too. But dogs get the credit, because honestly when was the last time you gave your partner a full body sniff-check?

Notes:
Mar 2019, Inverse

Mar 2019, The Sun

Study about the smell of Parkinson's:

Tuesday, September 3, 2019

Mind Control



It should come as no surprise that we look to others to help us make decisions, whether they're life-changing or everyday decisions. In a new study, we see that when mice choose what to eat, they utilize "taster mice" in their group that are the first to eat from a new food source.

I'm not sure what makes one a taster-mouse in the first place, but they do exist. In order for mice to decide at the colony level whether they should be eating from a certain food source, they don't ask their friends, and they don't check their newsfeed. Instead they use the smell of taster-mice whiskers.

In reality, mice don't do anything. Their brains are programmed by the smell of the taster-mice to steer them towards some food sources and away from others. Their repeated olfactory interactions with the taster mice and the social network they subsequently inform will rewire the neural network in their prefrontal cortex – the place where decisions are made. This alteration links the olfactory cue from the taster-mice to the reward center in the brain, which then motivates the mice to find that smell again.

We can think of all preference as following a similar pattern of social interaction and propagation. Taster-mice function as hubs of their social network. The difference is that humans are a bit more sophisticated. Instead of just transmitting the smell of safe, available food, the hubs of human networks spread styles, preferences, ideas, and information in general.

The interesting corollary is that in mice, the olfactory cues are literally re-wiring the pleasure-seeking centers of their brains, whereas in humans, all kinds of cues can redirect our behaviors. Olfaction is already known to be so tightly integrated with our decision-making and reward centers, but when the actual process by which this takes place is extrapolated to other senses, it suggests that we are way less in control of our own thoughts, desires and behaviors than we may think.


Notes
June 2019, phys.org

Post Script
By the way, casually mentioned in the article that presented this study, was the practice of "erasing memories" in the mice in the study. It's a technique used in optogenetics where a single neuron is zapped. I'm pretty sure it was only a few years ago that we first heard of this technique, and now it's just thrown in there like de rigueur. Eternal Sunshine here we come!

Post Post Script
On Mimetic Desire:
"All desire is a desire to be [someone else]"
-Rene Girard, Quand ces choses commenceront ... Entretiens avec Michel Treguer. Paris: arléa. ISBN 2-86959-300-7. p28. 1994.