تفاوت‌های جنسیتی در ارتباط‌های درون مغزی

Gender differences seen in brain connections

Human brains appear to come in at least two flavours: male and female. Now variations in the density of the synapses that connect neurons may help to explain differences in how men and women think.

Even when intelligence levels are equal, women and men excel at different cognitive tasks. But although brain size and neuron density differ between the sexes, these don't seem to correlate with cognitive differences. So, Javier DeFelipe at Complutense University in Madrid, Spain, and colleagues counted the number of synapses instead.

The brain tissue they analysed came from the left temporal cortex, a region of the brain involved in emotional and social processing, of four women and four men with epilepsy. The tissue itself was healthy, having been removed to allow doctors to access underlying damaged areas.

The men had up to 52% more synapses per brain "layer" in this region than the women. While the effect of high synaptic density in this region is unknown, the team suspects that there may be other regions where women out-synapse men.

Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073.pnas/0803652105)




آیا میان مغز زن و مرد دگرسانی‌ می‌باشد؟

Are There Differences between the Brains of Males and Females?
Renato M.E. Sabbatini,

That men and women are different, everyone knows that.

But, aside from external anatomical and primary and secondary sexual differences, scientists know also that there are many other subtle differences in the way the brains from men and women process language, information, emotion, cognition, etc.


Studying Differences in the Brain
There are now a number of sophisticated neuroscientific methods which allow scientists to probe minute differences between any two groups of brains. There are several approaches, brought forth by advancements in computerized image processing, such as tomography (detailed imaging of the brain using "slices"):

• volumetric measurements of brain parts: a region is defined, and the computer, working with a pile of slices, calculates the areas of the brain region, and then integrates numerically several areas in order to calculate its approximate volume. Statistical analysis of samples containing several brains are able to discover (or not) any differences in volume, thickness, etc.
  
• functional imaging: using advanced devices, such as PET (Positron Emission Tomography), fMRI (functional Magnetic Resonance Imaging) or Brain Topographic Electroencephalography, researchers are able to visualize in two and three dimensions what parts of brain are functionally activated when a given task is performed by the subjects.
  
• post-mortem examinations. The brains of deceased individuals are excised and sliced. Modern image analysis techniques are used to detect quantitative differences, such as the number and form of neurons and other brain cells, the area, thickness and volumes of brain regions, etc. ...
  

ساختار متفاوت سیستم سروتونین مغز در میان زن و مرد

Sex Differences In The Brain's Serotonin System
ScienceDaily (Feb. 17, 2008) —

A new thesis from he Swedish medical university Karolinska Institutet shows that the brain's serotonin system differs between men and women. The scientists who conducted the study think that they have found one of the reasons why depression and chronic anxiety are more common in women than in men ...




تفاوت‌ها جنسیتی در واکنش مغز به درد

Gender Differences In Brain Response To Pain
ScienceDaily (Nov. 5, 2003) —

A new UCLA study shows that different parts of the brain are stimulated in reaction to pain depending on gender. The research, which represents the largest gender-comparison study of its kind, focused on people with irritable bowel syndrome (IBS), one of the nation's most common chronic medical conditions. The findings may help develop and target better treatments for IBS and other illnesses ...




پژوهش‌های معاصر پرده از تفاوت‌های میان زن و مرد بر می‌دارد.

Scientists Find Sex Differences in Brain: Controversial Research Revealing Differences Between Men and Women

Harvard University President Lawrence H. Summers created a maelstrom when he suggested recently that innate differences in sex may explain why fewer women succeed in science and math careers.

He has since apologized for any misunderstanding his remarks may have caused. But is there any truth to the idea that men's and women's brains are, in fact, different? ...




تفاوت‌های زن و مرد در حس شوخ‌طبعی و واکنش به آن

GENDER DIFFERENCES ARE A LAUGHING MATTER, STANFORD BRAIN STUDY SHOWS
http://med.stanford.edu

STANFORD, Calif. — Need more evidence that men and women are different? Look no further than the Sunday funnies. According to a new Stanford University School of Medicine study, gender affects the way a person’s brain responds to humor. ...




تفاوت‌های جنسیتی در سلول‌های خاکستری و سپید در میان بزرگ‌سالان جوانِ تندرست: هم‌بستگی‌های آن در توانایی‌های ذهنی

Sex Differences in Brain Gray and White Matter in Healthy Young Adults: Correlations with Cognitive Performance
Ruben C. Gur1, Bruce I. Turetsky1, Mie Matsui1, Michelle Yan1, Warren Bilker1, 2, Paul Hughett1, and Raquel E. Gur1

1 Section of Neuropsychiatry, Department of Psychiatry, and 2 Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104

... We confirmed that women have a higher percentage of GM, whereas men have a higher percentage of WM and of CSF. These differences sustained a correction for total intracranial volume. In men the slope of the relation between cranial volume and GM paralleled that for WM, whereas in women the increase in WM as a function of cranial volume was at a lower rate. In men the percentage of GM was higher in the left hemisphere, the percentage of WM was symmetric, and the percentage of CSF was higher in the right. ...