Re: “Odor Basics�, Understanding and Using Odor

[Guest guest]

FYI - I just found a book by Herz at my local library, " The Scent

of Desire " . Dr. Herz has researched odors since the early 1990's and

written 50 original papers, so she knows the subject as well as anyone.

News to me: odors usually have a strong emotional component. This means

that some people like the skunk odor, becuase they first encountered it

at a good-humored moment. Or some may hate rose odors, since first

encountering that smell at a close relative's funeral.

Likewise, you can create responses in a group by telling them it's a

stimulating or depressing odor, no matter what odor is present -- or

none at all.

FYI: she does not believe in Multiple Chemical Sensitivity (MCS). I

cannot reproduce her arguments here, but you may want to read it

yourself.

Henry Slack

U.S. EPA Region 4

[Guest guest]

,

I've also had clients who had no sense of smell but would accurately react to certain " odors " as if they could smell them. Pinching the nose would stop the reaction. So some sort of physical " detection " was occuring beyond wild imaginings, psychodrama or the occult.

My experience agrees with your description of what happens a new developer " puts 2+2 together. " Humans are not " wired " to constantly find disturbance, they prefer to seek the opposite. Which, I guess, would also be accurately identified as " psychological. " Does that make it bad, also?

Carl Grimes

Healthy Habitats LLC

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>

>

> Here's another one for the discussion (see below).

>

> If I remember correctly, Herz claims MCS is fear based.

> Issomeone who has a peanut allergy told their efforts to avoid peanut exposure or their allergic

> reactions are " fear-based " ?

>

> When someonefirst develops MCS and puts 2+2 together, noticing that a lot of physical effects

> follow after an odiferous experience, there will be a period of adjustment where anything that

> smells will give rise to a pause that could be construed as fear based, but most people pass

> through that stage soon enough, realizing that not everything that smells causes a reaction.

>

> Herz and the other guy who recently wrote a popular book about our olafactory senses have not

> studied the science about chemicals and toxins and poisons etc. And or get paid by the fragrance

> industry. And fail to take into consideration that many chemicals without a smell, cause the same

> toxic responses.

>

> It is possible to perceive odours and not have any emotional or physicalresponse to them. Just

> like it is possible to die from things that have no odour - radon, carbon monoxide..., or to be

> harmed by other poisons when one's sense of smell has been compromised (allergic rhinitis for

> example wouldcontribute to that) And I'm told that it is not uncommon for people who have been

> poisoned by carbon monoxide to develop MCS. If it was a fear based response, they'd be walking

> around afraid of things that don't smell.

>

> linda

> (see article and release below... explaining one of the original purposes of having a nose)

>

>

>

> Nose's alarm system found

>

>

> http://www.thestar.com/sciencetech/article/309300

>

>

> ...

> " Scientists had thought such smells acted directly on nerve endings in

> the nose, but the study in mice suggests special cells in the tip of

> the nose act as air quality control sensors that protect the body from

> harmful chemicals.

> ...

> " This is one of these really hard-wired reflexes. It gives you time to

> get out, " Restrepo said in a telephone interview.

> ...

> And they said it takes more than a mere whiff of an offending odor to

> trigger the response. Restrepo said only potentially dangerous levels

> of odors can set off the protective gagging-and-coughing response.

> ...

> " There are some people who are especially sensitive to these

> irritants. "

> ...

>

>

>

> Irritating Smells Alert Special Cells, NIH-Funded Study Finds

>

> http://www.nidcd.nih.gov/news/releases/08/03_04_08.htm

>

>

> If you cook, you know. Chop an onion and you risk crying over your cutting board as a burning

> sensation overwhelms your eyes and nose. Scientists do not know why certain chemical odors,

> like onion, ammonia and paint thinner, are so highly irritating, but new research in mice has

> uncovered an unexpected role for specific nasal cavity cells. Researchers funded by the National

> Institute on Deafness and Other Communication Disorders (NIDCD), part of the National Institutes

> of Health, describe this work in the March issue of the Journal of Neurophysiology, now available

> online.

>

>

> Weihong Lin, Ph.D., of the University of Colorado Denver School of Medicine and University of

> land, Baltimore County, led the study which discovered that a particular cell, abundant near

> the entry of many animal noses, plays a crucial and previously unknown role in transmitting

> irritating and potentially dangerous odors. Dr. Lin and colleagues from both universities plus the

> Mount Sinai School of Medicine identified the role of this solitary chemosensory cell in transmitting

> irritating chemical odors in the noses of mice.

>

>

> Scientists have found similar solitary chemosensory cells in the nasal cavities, airways and

> gastrointestinal tracts of many mammals as well as fish, frogs and alligators; they think it is likely

> that they are also present in humans, explains Finger, Ph.D., one of the senior co-

> authors at the University of Colorado Denver.

>

>

> Prior to this work, scientists who study smell and taste thought that irritating odors directly

> stimulated the trigeminal nerve, which senses touch, temperature and pain throughout the head

> region, including the delicate membranes that line the inside of the nose. The research team,

> under the guidance of Diego Restrepo, Ph.D., found that solitary chemosensory cells scattered in

> the epithelium inside the front of the nose respond to high levels of irritating odors and relay

> signals to trigeminal nerve fibers.

>

>

> “This elegant research corrects an erroneous assumption about how irritating odors are perceived

> and expands our understanding of olfaction,” says F. Battey, M.D., Ph.D., director of

> NIDCD. “With further investigation, it also might lead to a better understanding of why some

> people are exceptionally sensitive to irritating odors.”

>

>

> Solitary chemosensory cells on the surface of the nasal cavity are in close contact with trigeminal

> nerve fibers which end just below the surface. Earlier research revealed that these cells contain

> bitter taste receptors and that bitter substances applied to the surface of the nasal cavity trigger a

> trigeminal nerve response.

>

>

> Intrigued, Drs. Restrepo and Finger decided to explore whether solitary chemosensory cells

> respond to irritating odors. Using nasal tissue from mice, the scientists measured a variety of

> changes in solitary chemosensory cells as they exposed the cells to low and high levels of several

> irritating, volatile chemical odors.

>

>

> Among their observations were changes in electrical activity in the cells—which indicates a

> response to an outside stimulus—and changes in intracellular calcium ion concentration—which

> indicates signaling to other cells. Their measurements demonstrated that the solitary

> chemosensory cells responded to the odors and relayed sensory information to trigeminal nerve

> fibers.

>

>

> Once stimulated, the trigeminal nerve will convey pain and burning sensations and can trigger

> protective reflexes such as gagging and coughing. The architecture of nasal tissue with solitary

> chemosensory cells on the surface and trigeminal nerve fibers just below allows the nose to

> detect a greater number of irritating odors, the scientists explain.

>

>

> Fortunately, the threshold for triggering a response is high, so exposure to a small amount of an

> irritating chemical, as might naturally emanate from some kinds of fresh fruit, will not bring on

> gagging and coughing. For example, lemons contain the volatile chemicals citral and geraniol but

> at levels too low to trigger a trigeminal response. Only high, potentially dangerous levels of odors

> will trigger the protective gagging-and-coughing response.

>

>

> The researchers point out that their findings provide an example of the Law of Specific Nerve

> Energies, conceived by Johannes Muller in 1826. Muller said that the way we perceive a

> stimulus depends on the nerve or sensory system that conveys it rather than the physical nature

> of the stimulus itself. In the case of irritating odors, we perceive them as irritating because they

> are transmitted via the trigeminal nerve, leading the brain to interpret the message as pain rather

> than as a smell.

>

>

> The researchers say their findings raise new questions about how irritating odors are detected.

> They say more research is needed to explore whether solitary chemosensory cells are

> programmed to recognize specific irritants, which receptors are involved, and what steps a solitary

> chemosensory cell uses to convert a chemical stimulus to a signal it relays to the trigeminal nerve.

>

>

> The NIDCD supports and conducts research and research training on the normal and disordered

> processes of hearing, balance, smell, taste, voice, speech and language and provides health

> information, based upon scientific discovery, to the public. For more information about NIDCD

> programs, see the Web site at www.nidcd.nih.gov.

> NIH—the nation’s medical research agency—includes 27 institutes and centers and is a

> component of the U.S. Department of Health and Human Services. It is the primary federal

> agency for conducting and supporting basic, clinical and translational medical research, and it

> investigates the causes, treatments and cures for both common and rare diseases. For more

> information about NIH and its programs, visit www.nih.gov.

>

>

>

>

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[Guest guest]

I think MCS is a simple matter of the brain trying to protect parts of itself from dangerous toxins by slowing down their blood flow...

[Guest guest]

I've lost a huge amount of my sense of smell and although some of it

has come back, its still very bad..but I do smell

more things,esp. bad things now.. and also putrefaction and perfumes..

for example, the other day it was some lotion or perfume

that a doctors receptionist was wearing.. some perfumes give me an

almost instant headache..

I was thinking, no this couldn't possibly be happening this quickly..

but it did..

Also, when that happens sometimes I acutely notice those old style

(60hz) flickering flourescent lights..

when i don't at other times! Its suddenly really bad when nobody else sees it.

s*** I should write this down because I don't often remember it after the fact..

I don't try to forget the specific details of those moments but it

happens.. we don't remember pain.