Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The female nose always knows: Do women have more olfactory neurons?

06.11.2014

Individuals show great diversity in their ability to identify scents and odors. More importantly, males and females greatly differ in their perceptual evaluation of odors, with women outperforming men on many kinds of smell tests.

Sex differences in olfactory detection may play a role in differentiated social behaviors and may be connected to one's perception of smell, which is naturally linked to associated experiences and emotions. Thus, women's olfactory superiority has been suggested to be cognitive or emotional, rather than perceptual.


The olfactory bulb transmits information from the nose to the brain.

Credit: Roberto Lent

Previous studies investigating the biological roots of greater olfactory sensitivity in women have used imaging methods that allow gross measures of brain structures. The results of such studies have been controversial, leaving unanswered the question of whether differences in olfactory sensitivity have biological roots or whether they represent a mere by-product of social and cognitive differences between genders.

The isotropic fractionator, a fast and reliable technique previously developed by a group of researchers at Federal University of Rio de Janeiro, measures the absolute number of cells in a given brain structure such as the olfactory bulb, which is the first brain region to receive olfactory information captured by the nostrils.

Using this technique, a group of researchers led by Prof. Roberto Lent from the Institute of Biomedical Sciences at the Federal University of Rio de Janeiro and the National Institute of Translational Neuroscience, Ministry of Science and Technology in Brazil, has finally found biological evidence in the brains of men and women that may explain the olfactory difference between genders.

The group examined post-mortem brains from seven men and 11 women who were all over the age of 55 at the time of death. All individuals were neurologically healthy and none worked in professions requiring exceptional olfactory abilities, such as coffee-tasting or professional cooking. By calculating the number of cells in the olfactory bulbs of these individuals, the group (that also included researchers from the University of São Paulo, the University of California, San Francisco, and the Albert Einstein Hospital in São Paulo) discovered that women have on average 43% more cells than men in this brain structure. Counting neurons specifically, the difference reached almost 50% more in women than men.

The question remains whether this higher cell number accounts for the differences in olfactory sensitivity between sexes. "Generally speaking, says Prof. Lent, larger brains with larger numbers of neurons correlate with the functional complexity provided by these brains. Thus, it makes sense to think that more neurons in the female olfactory bulbs would provide women with higher olfactory sensitivity".

The fact that few cells are added to our brains throughout life suggests that women are already born with these extra cells. But why do women's brains have this pre-wired ability? What mechanisms are responsible for this higher number of cells in their olfactory bulbs? Some believe this olfactory ability is essential for reproductive behaviors such as pair bonding and kin recognition.

If this holds true, then superior olfactory ability is an essential trait that has been inherited and then maintained throughout evolution, an idea expressed by Romanian playwright Eugene Ionesco when he said "a nose that can see is worth two that sniff".

The research paper entitled Sexual dimorphism in the human olfactory bulb: females have more neurons and glial cells than males has been published on PLOS ONE and is available at http://dx.plos.org/10.1371/journal.pone.0111733

Roberto Lent | EurekAlert!

More articles from Life Sciences:

nachricht One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie

nachricht The dark side of cichlid fish: from cannibal to caregiver
20.04.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>