UCLA team maps how genes affect brain structure, intelligence; dramatic images shed light on brain diseases, personality differences

November 04, 2001

UCLA brain mapping researchers have created the first images to show how an individual's genes influence their brain structure and intelligence.

The findings, published in the Nov. 5 issue of the journal Nature Neuroscience, offer exciting new insight about how parents pass on personality traits and cognitive abilities, and how brain diseases run in families.

The team found that the amount of gray matter in the frontal parts of the brain is determined by the genetic make-up of an individual's parents, and strongly correlates with that individual's cognitive ability, as measured by intelligence test scores.

More importantly, these are the first images to uncover how normal genetic differences influence brain structure and intelligence.

Brain regions controlling language and reading skills were virtually identical in identical twins, who share exactly the same genes, while siblings showed only 60 percent of the normal brain differences.

This tight structural similarity in the brains of family members helps explain why brain diseases, including schizophrenia and some types of dementia, run in families.

"We were stunned to see that the amount of gray matter in frontal brain regions was strongly inherited, and also predicted an individual's IQ score," said Paul Thompson, the study's chief investigator and an assistant professor of neurology at the UCLA Laboratory of Neuro Imaging.

"The brain's language areas were also extremely similar in family members. Brain regions that were found to be most similar in family members may be especially vulnerable to diseases that run in families, including some forms of psychosis and dementia."

The scientists employed magnetic resonance imaging technology to scan a group of 20 identical twins, whose genes are identical, and 20 same-sex fraternal twins, who share half their genes.

Using a high-speed supercomputer, they created color-coded images showing which parts of the brain are determined by our genetic make-up, and which are more adaptable to environmental factors, such as learning and stress.

To create the maps of genetic influences on the brain, the UCLA scientists teamed up with the National Public Health Institute of Finland, and the Finnish Universities of Helsinki and Oulu.

In a national initiative, the Finnish team tracked all the same-sex twins born in Finland between 1940 and 1957 -- 9,500 pairs of twins -- many of whom received brain scans and cognitive tests.

Their genetic similarity was confirmed by analyzing 78 different genetic markers. These individual pieces of DNA match exactly in identical twins, and half of them match in siblings.

Recent research has shown that many cognitive skills are surprisingly heritable, with strong genetic influences on verbal and spatial abilities, reaction times, and even some personality qualities, including emotional reactions to stress.

These genetic relationships persist even after statistical adjustments are made for shared family environments, which tend to make members of the same family more similar. Until this study, little was known about how much individual genotype accounts for the wide variations among individual brains, as well as individual's cognitive ability.

The UCLA researchers are also applying this new genetic brain mapping approach to relatives of schizophrenic patients, and individuals at genetic risk for Alzheimer's disease, to screen them for early brain changes, and help understand familial risk for inherited brain disorders where specific risk genes are unknown.
-end-
Other UCLA researchers involved in the project are Tyrone Cannon, a professor of psychiatry and biobehavioral and human genetics, and Arthur Toga, professor of neurology and director of the UCLA Laboratory of Neuro Imaging.

Images from the study are available online for viewing or downloading at http://www.loni.ucla.edu/~thompson/MEDIA/NN/IMAGES/

University of California - Los Angeles

Related Brain Articles from Brightsurf:

Glioblastoma nanomedicine crosses into brain in mice, eradicates recurring brain cancer
A new synthetic protein nanoparticle capable of slipping past the nearly impermeable blood-brain barrier in mice could deliver cancer-killing drugs directly to malignant brain tumors, new research from the University of Michigan shows.

Children with asymptomatic brain bleeds as newborns show normal brain development at age 2
A study by UNC researchers finds that neurodevelopmental scores and gray matter volumes at age two years did not differ between children who had MRI-confirmed asymptomatic subdural hemorrhages when they were neonates, compared to children with no history of subdural hemorrhage.

New model of human brain 'conversations' could inform research on brain disease, cognition
A team of Indiana University neuroscientists has built a new model of human brain networks that sheds light on how the brain functions.

Human brain size gene triggers bigger brain in monkeys
Dresden and Japanese researchers show that a human-specific gene causes a larger neocortex in the common marmoset, a non-human primate.

Unique insight into development of the human brain: Model of the early embryonic brain
Stem cell researchers from the University of Copenhagen have designed a model of an early embryonic brain.

An optical brain-to-brain interface supports information exchange for locomotion control
Chinese researchers established an optical BtBI that supports rapid information transmission for precise locomotion control, thus providing a proof-of-principle demonstration of fast BtBI for real-time behavioral control.

Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.

Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.

Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.

Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.

Read More: Brain News and Brain Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.