Image from: pixabay.com
Ok, last week's TIL post was about a study that revealed how their partner's smell helps women feel safer and reduce cortisol levels. The study claimed women's more acute sense of smell to be the reason for using them as guinea pigs. I was intrigued to look further into it and so I did.
According to another research from the Institute of Biomedical Sciences at the Federal University of Rio de Janeiro, which took place in 2014, women's brain region in charge of smell is more advanced than in men.
The "guinea pigs"
The scientists studied the brain of 11 dead women and 7 dead men. The subjects were all 55-94 years old, had lived in the same environment of moderate to high environmental pollution levels, were neurologically healthy and had never worked in positions requiring high olfactory abilities (like a professional cook). According to a past genomic DNA analysis, "Brazilians subjects can be considered representative of many different ethnic ancestries".
The method
The technique used in order to count the absolute cell number of a specific brain structure (in the present study: the olfactory system) is called isotropic fractionator. Up untill then, imaging methods would reveal a gross number of cells and lacked in accuracy (leaving questions as to whether the discrepancies measured were due to biological or social and cognitive differences.
The findings
There were no significant differences regarding mean mass of the olfactory bulb between men and women, age groups or brain hemisphere. The measurements revealed that women have 43.2% more cells than men in the specific brain structure. For neurons, the difference would reach almost 50% (49.3%). The non-neuronal number was also 38.7% higher in women. Coming to density, the differences were as notable as above, with women showing higher density of total cells, neurons and non-neurons compared with men.
Image from: maxpixel.freegreatpicture.com
The questions that rose
Why do women have such an advanced olfactory bulb system? What purposes does it serve?
One possible explanation is evolution, bigger brains serve greater and more complex functions (as shown by a study on elephants). A second one is based on reproduction. Both sexes seem to have equal amount of smell receptors. In neuro-imaging experiments, women showed higher activity in the frontal and temporal lobes than men. Moreover, in odor evaluating tests, women also seem to process odors differently, which implies a possible role of estrogen levels in smell recognition.
Some studies have shown women have certain odor sensitivity, while others failed to produce such results. According to this study, women exhibit greater odor sensitivity due to repetitive exposure to certain odors but only after puberty. This is suggested to serve reproduction, as greater sensitivity in smell aids in pair bonding and kin recognition, a trait that has been maintained through centuries of evolution.
There is still a definite answer pending as to whether the higher number of neurons is responsible for the enhanced sense of smell in women. Another question that hasn't been answered with certainty is whether women are born equipped with more olfactory bulb cells or acquire them afterwards. But since the accute smell does not abandon women even after menopause, then it cannot necessarily be hormone-regulated.
Are reproductive hormones to blame?
A study has indicated that estrogens increase olfactory performance, whereas androgens decrease it. But there have been contradicting results from other studies that have revealed a teenage girls' outperformance over boys in odor identification. Accordingly, analogous results were revealed in experiments with post-menopause women and same-age men. All these lead to the conclusion that reproductive hormones ang aging cannot have a great role in women's better smelling abilities.
Image from: flickr.com - Creator: Oliver Clarke - License
Adult neurogenesis and aging have a part?
Although in many mammals neurogenesis occurs during lifetime, in humans this is not the case. The addition of new neurons is insignificant. Therefore, scientists can conclude that the more advanced olfactory bulb system in women is due to "embryonic proliferation and/or to postnatal cell death controlled by hormones or by inhibitory neurotransmitters".
Aging does not seem to influence women's outperformance, although there are conflicting studies in this field. However, the decrease in neurons due to aging does not seem to affect women as much as men, since they still maintain their "superiority" even after the deterioration that comes with old age.
TL;DR
Women's part of the brain that is responsible for smell is more advanced and equipped with more cells than men's. Therefore, women can detect and identify odors easier. Women are probably born bearing more cells in the specific part of their brains and this could be driven by reproductive reasons.
There has been a wide bibliography and studies on the field that reveal fascinating results. The more you look into it the more amazed you will be by human nature.
References
journals.plos.org
sciencedaily.com
livescience.com
scientificamerican.com
scielo.br
frontiersin.org
nature.com
academic.oup.com
Thank you so much for your time!
Until my next post,
Steem on and keep smiling, people!
Ha! I am happy you looked into this and provided a more in-depth article about the cited statement of your last article. :)
Thank you for your work! :)
Yeah! It turned out a very interesting topic, although some terms on the paper gave me a hard time. I believe I got everything right :)
Thank you for reading @mountain.phil28! :D
Like I needed this post to tell me that women smell better than men. First of all, they're less hairy, which means .... oh, I misunderstood the title.
Not too many years ago, half the world's population were cooks and nutritionists. They were called women, and they were responsible for what their children and their men ate, and whether it led to health and growth or the reverse. So maybe they needed to be able to smell better so as to detect poisons better. Given how our sense of taste owes a lot to our sense of smell (I believe you are familiar with the 'pinch your nose, close your eyes, and have someone give you different foods and see if you can tell what they are' test), it's not too far-fetched to theorize their sense of smell may be superior for this reason.
Maybe. Who knows! It's as good a theory as any.
I laughed at your first line :P
Interesting theory this one you have here. It still serves the greater cause of survival and protecting the family, after all, the basis of our life is about this.
The evolution to the rescue one more time. Thank you, for I think my question on your last post on olfactory abilities is finally answered.
Oh yes, evolution is really amazing after all! Thank you for reading @greenrun! I hope I got you all covered now :)
More than covered :)
I wonder if there is a biological and thus evolutionary advantage to women's sense of smell, as I know with other mammals, the ability to smell their own offspring is often helpful in the females especially in group/pack mammals which I would include the human animal in.
Very interesting.
There have to be simple in their complexity reasons for this. I don't believe that there is anything left to chance in this world. And looking into such topics only raises more and more awe and respect towards the greater power-entity-energy (call it whatever you wish) that created us.
Thank you for reading :)
So true. And I wonder if individuals sense of smell is as unique as our fingerprints, as they say one person's red might not look anything like anothers?
I agree, the greater power entitiy is definitely mysterious and I think has a sense of humour sometimes. I mean, all you have to do is look at a giraffe or a platypus and know someone with a sense a humour had their hand in that :)
I guess there must be a uniqueness, I haven't looked into it.
Ahahahaha! You are absolutely right :P
May this have something to do with the link between gonadotropin cells and the olfactor bulb?
There is a population of cells which arise in the olfactor bulb, and during our development migrate to the pituitary gland. Once there they're responsible for the production of gonadotropin releasing hormone (GnRH) which goes on to stimulate our sexual development.
There is actually a condition called Kallmann's syndrome where these cells fail to migrate from the olfactory bulb to the pituitary gland. In this syndrome people will either fail to start of finish puberty and often need hromone replacement surgery. But they also suffer from anosmia, or the inability to smell! It's pretty rare, but an interesting condition none the less.
Interesting, you may be on to something! But, ultimately both genders release nearly the same amount of GnRH
I haven't looked further into it to be honest. But there was no mention about it in the present study. Thank you for the enlightening comment @tfcoates! :)
:) No problems, an interesting area to keep an eye on in the future :)
I have a different theory.
olfactory is the THE ONLY sense in the body which bypasses the thalamus and all input travels straight to the amygdala. The amygdala is the emotional center of the brain.
Naturally women are more emotional than men.
Oh we are more emotional, I guess you gave me another idea for next week's TIL (if I don't come up with anything else)
Thank you!
Ha! I'm glad you saw it and provided a deeper article about the reference to your last article.
Thank you and love from Pakistan....
Upvote you maam...
Thank you!
Greetings!
So, this is one reason to say why women are born powerful than men. Very interesting article.
Not powerful, just different and more favored in certain aspects. Men do other things better.
Ha ha ha. Ya maybe. :o)
I also admit it, women have good sense of smell. This ability is seen when a woman can detect various sources of smell around it. Then in a relationship, a man who wants to date first with a woman, using perfume is mandatory. Good olfactory ability will make a man able to captivate the woman even though his face is not very handsome. Little additional information, men have the ability to see better, especially in low light conditions. : D
Thank you for the input! Men and women are so different but still remain so similar, they are all human! :)
Yes ... I remember the book that John Gray wrote by his wife: Men Are from Mars, Women Are from Venus. All that describes men and women are very different. To be able to understand each other is to unite them on earth. : D
I 've heard of that book, I just never got hold of it. Is it any good?
Yeah.. In my opinion, the book is useful in studying the differences between men and women, although there are certain chapters that are difficult to understand....
Wow! I love this topic I must say. But then I totally agree with you on this;
Thank you!
great post, I really like your posts.
Thank you!
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upvote newpost my senior @ruth-girl
Great post and it's really true women smell good then men
Thank you!
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interesting!
Interesting :)
Thanks
I am surprised that if there is a biological and ideal evolution advantage, then the ability to kiss their own children, often in groups / pack lovers, often with the feeling of smell of women, as I know with other parameters. Become a helper in which I will be involved in animals. Inside.
Interesting article. Perhaps you should research something on colour as well. Why tf do women have so much colour sense and a lot of us men can only manage to recognize primary colours?
Thank you! I had once made a post on how color perception is different, but didn't go any further into sex-discrepancies. Perhaps something to keep in mind for the future :)
Haha, are you for real?
Yes!