30 November 2009

Male and Female Brains, and Other Brain Stuff

In the face of danger, male brains focus on the need for action, whereas female brains focus on their own emotional response to danger, say Polish researchers.
For the study, Dr. Urbanik and colleagues recruited 40 right-handed volunteers, 21 men and 19 women, between the ages of 18 and 36. The volunteers underwent fMRI while viewing pictures from the International Affective Picture System (IAPS), a widely used, standardized testing system comprised of several thousand slides of various objects and images from ordinary life designed to evoke defined emotional states. The images were displayed in two runs. For the first run, only negative pictures were shown. For the second run, only positive pictures were shown.

While viewing the negative images, women showed decidedly stronger and more extensive activation in the left thalamus, which relays sensory information to and from the cerebral cortex, including the pain and pleasure centers. Men exhibited more activation in the left insula, which gauges the physiological state of the entire body and then generates subjective feelings that can bring about actions. Information from the insula is relayed to other brain structures involved in decision making.

"The brain activation seen in the women might indicate stronger involvement of the neural circuit, which is associated with identification of emotional stimuli," Dr. Urbanik said. "The more pronounced activation of the insular cortex in the men might be related to the autonomic components, such as elevated heart rate or increased sweating, that accompany watching emotional material."

The autonomic nervous system controls involuntary functions, including respiration, heart rate and digestion, and helps to adjust certain functions in response to stress or other environmental stimuli. It is responsible for the body's "fight or flight" response to threatening situations.

"In men, the negative images on the slides were more potent in driving their autonomic system," Dr. Urbanik said. "This might signal that when confronted with dangerous situations, men are more likely than women to take action." _SD
Once you learn to ride a bike, you are not likely to forget how. Motor learning is profound and lasting -- and fast. It has been found by UC Santa Cruz researchers that new synapse formation begins to occur within 1 hour of initiation of training for motor skills.
"We found very quick and robust synapse formation almost immediately, within one hour of the start of training," said Yi Zuo, assistant professor of molecular, cell and developmental biology at UCSC.

Zuo's team observed the formation of structures called "dendritic spines" that grow on pyramidal neurons in the motor cortex. The dendritic spines form synapses with other nerve cells. At those synapses, the pyramidal neurons receive input from other brain regions involved in motor memories and muscle movements. The researchers found that growth of new dendritic spines was followed by selective elimination of pre-existing spines, so that the overall density of spines returned to the original level. _SD

Want to grow new brain cells? You need to eat the right foods, among other necessary changes. Barcelona researchers have found that an "LMN" diet prompts mouse brains to grow new stem cells leading to the production of new neurons of various types.
Universitat Autònoma de Barcelona (UAB) researchers have confirmed that a diet rich in polyphenols and polyunsaturated fatty acids, patented as an LMN diet, helps boost the production of the brain's stem cells -neurogenesis- and strengthens their differentiation in different types of neuron cells.

The research revealed that mice fed an LMN diet, when compared to those fed a control diet, have more cell proliferation in the two areas of the brain where neurogenesis is produced, the olfactory bulb and the hippocampus, both of which are greatly damaged in patients with Alzheimer's disease. These results give support to the hypothesis that a diet made up of foods rich in these antioxidant substances could delay the onset of this disease or even slow down its evolution. _SD
Early intervention in autism may increase the child's IQ and social skills. University of Washington researchers claim that their intervention in 18 to 30 month old toddlers improved the IQ of children an average of 18 points.
The children were separated into two groups, one that received 20 hours a week of the intervention – two two-hour sessions five days a week – from UW specialists. They also received five hours a week of parent-delivered therapy. Children in the second group were referred to community-based programs for therapy. Both groups' progress was monitored by UW researchers. At the beginning of the study there was no substantial difference in functioning between the two groups.

At the conclusion of the study, the IQs of the children in the intervention group had improved by an average of approximately 18 points, compared to a little more than four points in the comparison group. The intervention group also had a nearly 18-point improvement in receptive language (listening and understanding) compared to approximately 10 points in the comparison group. Seven of the children in the intervention group had enough improvement in overall skills to warrant a change in diagnosis from autism to the milder condition known as 'pervasive developmental disorder not otherwise specified,' or PDD-NOS. Only one child in the community-based intervention group had an improved diagnosis.

"We believe that the ESDM group made much more progress because it involved carefully structured teaching and a relationship-based approach to learning with many, many learning opportunities embedded in the play," Rogers said. _Eurekalert
Sucess for such interventions much past 30 months of age is not likely to occur. Developmental windows for brain centers occurs from posterior to anterior, from near birth for visual development to final myelinisation of the pre-frontal pathways around the age of 25 years.

This UW autism research suggests that interventions targeted to particular levels of brain development -- occurring at the proper times -- can partially compensate for genetic tendencies toward developmental failure (and may possibly compensate partially for early damaging environmental exposures).

UK hospital offers high quality 3-D MRI brain scans of babies inside the uterus. The hospital claims to be the first in the world to offer a new "high speed" MRI scan that compensates for fetal movement in the womb.

Update 4 Dec 09: Here is a story about earlier research from the University of Pennsylvania, Philadelphia, looking at male and female responses to stress. The findings of this team were very similar to the results of the Polish study linked above.

Put simply: In general, women deal with stress by looking for allies and "rescuers". Men deal with stress by either flight or direct struggle. The study models used by both the Pennsylvania researchers and the Polish researchers were highly artificial, of course, taking place in brain scanning devices.

Can you design an "ethical" study placed in a more realistic setting?


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Blogger Sojka's Call said...

Good information on the LMN diet re brain health. Thanks for posting!

Monday, 30 November, 2009  
Blogger jimpurdy1943@yahoo.com said...

So researchers in Barcelona, Spain, advocate a diet rich in olive oil and wine? Is that a surprise?

Monday, 30 November, 2009  

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