Why is the thinning area in male pattern baldness exactly the galea area ?

[Archon]

What about Ponten's failure to see any objective improvement in his 56 patients after galeotomy, along with several seen by Nordström himself? Don't all those count as "tests" of the galea theory?

How is this any different from saying "bald men who are castrated do not see any objective improvement, therefore DHT must have nothing to do with hairloss"? It seems just as much like jumping to conclusions based on a faulty or incomplete understanding of what the theory entails.

Although maybe we're just not thinking about the same "galea theory" or something. :dunno:

 

[cyberprimate]

How is this any different from saying "bald men who are castrated do not see any objective improvement, therefore DHT must have nothing to do with hairloss"?

Nice one.

 

[freakout]

Smoke Belching and Androgenetics

A mechanic named Hamilton was confronted with the persistent problem of smoke belching. Unable to procure a tech manual from the 'Maker' of the vehicle, he conducted his own research to diagnose the car's undesirable 'trait'.

His efforts finally paid out when he discovered that every time he took out the 'oil pan' 'dangling' beneath the engine between the two 'wheels', the smoke vanished. He surmised that the oil was involved in smoke belching.

Other 'mechanics' chimed in and added that the car was probably 'predisposed' to spewing smoke after '12 years'.

Rather than funding research to find out why burnt oil was spewing at the tail pipe, 'chemical' companies capitalized on Hamilton's studies and found ways to neutralized the 'oil' instead which lead to side-effects such as spark plug erectile dysfunction.

.. and the age of Androgenetics was born.
----------------------------------
Blaming the galea is like:

blaming the sun for sunburn
blaming the water for drowning
blaming the gun for gunshot wound
blaming the engine oil for smoke belching
blaming the tree bumping into it
blaming gravity for breaking a bone
blaming androgens for baldness

None of the above can be blamed because they are constants of the equation - mere references for diagnosis and investigation.

Just because you are capable of changing the constants does not make the sum correct.

 

[Bryan]

How is this any different from saying "bald men who are castrated do not see any objective improvement, therefore DHT must have nothing to do with hairloss"?

I can tell you how it's different, it's really pretty simple. Men who are castrated do not continue to lose hair at the same rate then they did before, in fact their hair loss stops all together in most cases. In contrast men who received a galeotomy continued to bald at the same rate.

Exactly! Here is what Nordström himself said in his 1978 study (added emphasis is my own):

...In 1963, Ponten reported that after frontal galeotomy he could not find any objective improvement in his 56 patients and he still holds this view concerning this operation (personal communication, 1976).

The present author has seen several patients who have undergone frontal galeotomy and later developed an advanced degree of male pattern baldness. The popularity of this operation has waned.

It's amazing to me that a few people on hairloss sites still take this "galea theory" seriously. I don't think it's much different from other ridiculously speculative theories that were in vogue around the turn of the century, like how balding supposedly comes about from wearing hats that are too tight!

 

[balder]

The occipital muscles behind the ears are engaged when yawning:

http://www.ncbi.nlm.nih.gov/pubmed/2689156

Occipitofrontalis muscle: functional analysis revealed by electromyography.
Bérzin F.
Abstract

The occipital and frontal bellies of the right occipitofrontalis muscle were studied electromyographically in thirty volunteers in various movements, using a special steel electrode (80 microns diameter). The occipital and frontal bellies have independent actions despite the galea aponeurotica. The frontal belly initially raises the homolateral eyebrow, followed by a displacement of the galea aponeurotica, drawing the scalp forward; therefore it is active in the formation of the transversal wrinkling in the forehead. The occipital belly eventually can be active during raising of the eyebrown, nevertheless it does not interfere with the action of the frontal belly. The occipital belly alone is responsible for drawing back the galea aponeurotica. The occipital belly is also active during smiling and yawning, and can be active during the movements of the auricula.

Yawning stimulates nitric oxide production?

http://planetthrive.com/2010/11/yawn/

Other neurochemicals and molecules involved with yawning include acetylcholine, nitric oxide, glutamate, GABA, serotonin, ACTH, MSH, sexual hormones, and opium derivate peptides. In fact, it’s hard to find another activity that positively influences so many functions of the brain. “

Flexing the occipital muscles for several minutes each day might be beneficial for the scalp hair follicles on the galea region of scalp.

:dunno:

More research is required :innocent:

 

[freakout]

Does the recipient site influence the hair growth characteristics in hair transplantation?
http://www.ncbi.nlm.nih.gov/pubmed/12269871

If the recipients are mice, miniturized "Androgenetic Alopecia" hair will grow into terminal in just four months. Read the discussion in my signature.
Those mice hold the secret to regrowth. :crazy:

 

[balder]

Does the recipient site influence the hair growth characteristics in hair transplantation?
http://www.ncbi.nlm.nih.gov/pubmed/12269871

If the recipients are mice, miniturized "Androgenetic Alopecia" hair will grow into terminal in just four months. Read the discussion in my signature.
Those mice hold the secret to regrowth. :crazy:

Balding follicles appear to be targeted by the immune system for termination.

On an immune compromised mouse, hair regrows. Hair also regrows on some people taking immune suppressing drugs.

Transplanting a balding hair follicle from the galea region of scalp to another area/bodypart does not halt the balding process in a person with a healthy immune system. The hair appears to be sending out signals as if it is a foreign body.

If scalp hairs are genetically programmed to miniaturize in the presence of androgens, that still does not explain why scalp in the galea region becomes thin, tight and "shiny". The skin on the galea region of scalp appears to experience accelerated aging in people with advanced male pattern baldness.

A hypoxia condition in the galea region might explain the accelerated aging and the immune attack.

More research is required :woot:

 

[freakout]

Balding follicles appear to be targeted by the immune system for termination.

On an immune compromised mouse, hair regrows. Hair also regrows on some people taking immune suppressing drugs.

That was the argument of one of the screwball poster However, hair follicles are immune-privileged. (Jahoda 1999)

Also, there were 28 men 11 women there. ALL regrew their hair on mice. Are all of them immunologicaly related?? Statistically, I don't think so.

If there is an immune-response, then its affecting the follicle's surrounding or other systems, perhaps.

Also that study shows that hairs were NOT genetically programmed to miniaturize with androgens.

 

[balder]

However, hair follicles are immune-privileged. (Jahoda 1999)

One of the foremost baldness experts, Dr. Proctor, says that the immune system is definitely involved in male pattern baldness. :notworthy

http://www.health-marketplace.com/artic ... growth.htm

Hormones, Immunity and Hair

The latest scientific model to explain baldness involves the action of dihydrotestosterone (DHT)-the major metabolite of the male hormone testosterone. Scientists have found that excessive secretion of DHT stimulates a localized immune reaction, which, in turn, generates an inflammatory response that damages hair follicles, resulting in their miniaturization and eventual loss.

What appears to happen is that DHT (and, perhaps, other androgenic hormones) causes the immune system to react to the hair follicles in the affected areas as foreign bodies. This is suggested by the presence of hair follicle antibodies as well as by the infiltration of immune system cells around the hair follicles of balding men and women.

Blood vessel diseases such as atherosclerosis may also contribute to accelerated hair loss, as evidenced by the higher incidence of these diseases in balding persons.

Successful prevention and treatment of accelerated hair loss necessitates dealing with some, if not all, of these factors involved in the process, except for the genetic component of baldness.

 

[balder]

Role of UV radiation
Progressive thinning of scalp hair in Androgenetic Alopecia results in a gradual decline in natural protection of the scalp from UV radiation (UVR). While the consequences of sustained UVR on the unprotected scalp are obvious and well appreciated, specifically photocarcinogenesis and solar elastosis, the effects of UVR on hair loss have widely been ignored. However, clinical observations and theoretical considerations suggest that UVR may have negative effects (overview in: Trüeb 2003): acute telogen effluvium from UVR has been described (Camacho et al 1996), and the production of porphyrins by Propionibacterium sp. in the pilosebaceous duct, with photoactivation of porphyrins (Johnsson et al 1987) leading to oxidative tissue injury, may contribute to follicular microinflammation operative at the level of the follicular stem cells. Histopathologically elastosis is regularly found in scalp biopsies, especially in alopecic conditions. A recent study demonstrated a relationship between the degree of scalp elastosis and severity of Androgenetic Alopecia (Piérard-Franchimont et al 2002): the scalp dermis was significantly thicker in Androgenetic Alopecia than in unaffected control subjects. The difference was due to severe elastosis in baldness. The earliest signs of solar elastosis preceded hair thinning. When elastosis was thicker than 0.2 mm, a negative exponential correlation was found between hair diameter and severity of solar elastosis.


http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2695167/


whether Androgenetic Alopecia is the lone cause for all hairloss in the galea region I don't know (I believe it is not) However, the above is logical to me and does not depend on the initial cause for the lack of scalp hair even though the researchers "assumed" Androgenetic Alopecia! (unless you believe androgens have an effect on UVR absorbtion as well)

male pattern baldness appears to cause accelerated aging of the scalp. Sunlight also causes premature aging of the skin, especially in fair-skinned people.

Excessive sun exposure probably accelerates the male pattern baldness process, yes :sun:

 

[freakout]

One of the foremost baldness experts, Dr. Proctor, says that the immune system is definitely involved in male pattern baldness. :notworthy
http://www.health-marketplace.com/artic ... growth.htm

I don't totally discount immune-related cases but the link is a web magazine. Where can I find the study itself?

I said: Since hair follicles are immune-privileged, any case of immune-response would have occured in the follicle's surrounding (local or niche environment).

An immune-response is a mere consequence. And the damage to the follicles was a mere consequence of the consequence.

 

[balder]

I said: Since hair follicles are immune-privileged...

It appears that hair follicles are not immune privileged for all phases of the hair cycle, just during the anagen phase... :argue:

http://www.ncbi.nlm.nih.gov/pubmed/14582671

Abstract

This essay reviews the available evidence that the proximal hair follicle epithelium generates and maintains an area of relative immune privilege during a defined segment of the hair cycle (i.e., during anagen).

 

[freakout]

It appears that hair follicles are not immune privileged for all phases of the hair cycle, just during the anagen phase...
http://www.ncbi.nlm.nih.gov/pubmed/14582671

Thanks for the link. It's still in the hypothetical stage though. uke:

The fact is: when Jahoda transplanted follicles into his wife's arm, it went thru all the the cycles.

My personal view on this is: If male pattern baldness is primarily caused by an immune-response, there won't be a pattern. Hence, such a response could only be a consequence of a more complex matter like low blood supply which can cause increased cell death and may lead to immune responses in some cases.
http://www.ncbi.nlm.nih.gov/pubmed/2715645
http://www.ncbi.nlm.nih.gov/pubmed/8628793

 

[balder]

My personal view on this is: If male pattern baldness is primarily caused by an immune-response, there won't be a pattern.

There would be a pattern if the immune response is primarily confined to the galea region of scalp...

Androgens appear to cause hair follicle miniaturization in the galea region of scalp, yet, androgens also cause BODY-hair GROWTH in other places.

This seems to signify a direct action of androgens on hair.

The galea region hair miniaturization process is it a type of secondary effect or is it a result of the genetics within the hair follicles themselves, whereby the follicle is pre-programmed to shrink?

Now there is a lack of progenitor cells...

http://www.uphs.upenn.edu/news/News_Rel ... ctivation/

Using cell samples from men undergoing hair transplants, the team compared follicles from bald scalp and non-bald scalp, and found that bald areas had the same number of stem cells as normal scalp in the same person. However, they did find that another, more mature cell type called a progenitor cell was markedly depleted in the follicles of bald scalp.

The researchers surmised that balding may arise from a problem with stem-cell activation rather than the numbers of stem cells in follicles. In male pattern balding, hair follicles actually shrink; they don’t disappear. The hairs are essentially microscopic on the bald part of the scalp compared to other spots.

“We asked: ‘Are stem cells depleted in bald scalp?’â€￾ says Cotsarelis. “We were surprised to find the number of stem cells was the same in the bald part of the scalp compared with other places, but did find a difference in the abundance of a specific type of cell, thought to be a progenitor cell,â€￾ he says. “This implies that there is a problem in the activation of stem cells converting to progenitor cells in bald scalp.â€￾

 

[Ende]

lol. What's this? One of the first Rogaine subjects?

 

[balder]

lol. What's this? One of the first Rogaine subjects?

we are cousins with our fellow primates on the evolutionary tree of life...

 

[freakout]

There would be a pattern if the immune response is primarily confined to the galea region of scalp...

Androgens appear to cause hair follicle miniaturization in the galea region of scalp, yet, androgens also cause BODY-hair GROWTH in other places.

This seems to signify a direct action of androgens on hair.

The galea region hair miniaturization process is it a type of secondary effect or is it a result of the genetics within the hair follicles themselves, whereby the follicle is pre-programmed to shrink?

Now there is a lack of progenitor cells...

http://www.uphs.upenn.edu/news/News_Rel ... ctivation/

My take in genetics is: If genetics is within the follicles, they will continue to shrink when transplanted to mice. Instead they grew like hell. I think the genetic component of male pattern baldness lies on the original site. Our skin (scalp) has genetic properties on elasticity. Our CVD has genetic properties. Any of these could affect the follicles.

Me take on body hair growth after puberty could be direct but could also be an indirect action.

The galea region is a naturally susceptible area. The fact that male pattern baldness almost always occur there but not necessarily follow its complete pattern is merely an indication that male pattern baldness is more complex than a mere biochemical or immunological cause.

I have a question that's bugging me: Does hair growth cycles really exists? Or is it: when a hair falls off, signifies follicle death and be replaced by new follicles from stem cells?? :dunno:

 

[balder]

I have a question that's bugging me: Does hair growth cycles really exists? Or is it: when a hair falls off, signifies follicle death and be replaced by new follicles from stem cells?? :dunno:

http://www.nature.com/jidsp/journal/v8/ ... gure-title

A schematic diagram of an epidermopilosebaceous unit (EPU) in hair-bearing skin. The unit consists of the epidermis and the hair follicle with its associated sebaceous gland. The bulge contains a population of putative keratinocyte stem cells that can give rise to (pathway 1) a population of pluripotent and rapidly dividing progenitor (transit amplifying or TA) cells in the follicular matrix that yields the hair shaft. Alternatively, the bulge stem cells can give rise to the stem/progenitor cells of the epidermis (pathway 2). It is hypothesized here that the epidermal stem cell represents a form of bulge-derived, young TA cell (stem cell or SC/TA1,2...?). The long, curved arrow denotes the demonstrated capability of adult epidermal cells to form a new hair follicle in response to appropriate mesenchymal stimuli (Ferraris et al, 1997;Reynolds et al, 1999). B, bulge; E, epidermis; FP, follicular or dermal papilla; M, matrix keratinocytes; ORS, outer root sheath; S, hair shaft; SC, stem cells; SG, sebaceous gland; TA, transit amplifying cells. (Reproduced from Lavker and Sun, PNAS 97: 13473, 2000, with permission.)

 

[freakout]

So does this qualify as a new follicle from stem cell replacing the old follicle?

I tend to become reluctant when I see the word 'hypothesized' and 'in vitro'.

 

[balder]

So does this qualify as a new follicle from stem cell replacing the old follicle?

I tend to become reluctant when I see the word 'hypothesized' and 'in vitro'.

It would be nice to have a simple mechanistic or hydraulic explanation for male pattern baldness but the complexities of cell biology and genetics seem to reveal a very complicated relationship... :dunno:

http://en.wikipedia.org/wiki/Castration ... nsequences

Castration prevents male pattern baldness if it is done before hair is lost. However, castration will not restore hair growth after hair has already been lost due to male pattern baldness.

Genetics and androgens appear to be the smoking gun in male pattern baldness.

Still, more research is required with respect to the relationship between skeltal muscles, the endocrine system, the occipitofrontalis and male pattern baldness.