Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Discover New Gene Essential For The Development Of Normal Brain Connections Resulting From Sensory Input

09.01.2004


Biologists at the University of California, San Diego and the Johns Hopkins University have discovered a gene that plays a key role in initiating changes in the brain in response to sensory experience, a finding that may provide insight into certain types of learning disorders.


Images of neurons from normal mice (left) and from mice lacking CREST gene (right) Credit: Anirvan Ghosh



After birth, learning and experience change the architecture of the brain dramatically. The structure of individual neurons, or nerve cells, changes during learning to accommodate new connections between neurons. Neuroscientists believe these structural changes are initiated when neurons are activated, causing calcium ions to flow into cells and alter the activity of genes.

In a paper featured on the cover of the January 9th issue of the journal Science, biologists at UCSD and the Johns Hopkins University medical school report the discovery of the first gene, CREST, known to mediate these changes in the structure of neurons in response to calcium.


“We discovered the gene CREST using a new method we developed to identify genes that are switched on in the presence of calcium,” says Anirvan Ghosh, a professor of biology at UCSD who headed the study. “The brains of mice lacking CREST appear normal at birth, but do not develop normally in response to sensory experience after birth. This parallels some learning disorders in humans where the child appears normal initially, but by the age of two or three years it becomes clear that there are failures in the acquisition of new knowledge.”

Neurons from normal mice develop a highly branched tree-like structure. In fact, much of the growth of the brain that occurs soon after birth is the development and branching of dendrites—the part of a nerve cell that receives input from other neurons. Thus, this branching allows neurons to form many different synapses, or connections, with many other neurons, permitting much cross talk between them. Neurons taken from mice lacking the CREST gene are more linear, like a plant shoot.

In addition, when individual neurons kept alive in a Petri dish are stimulated with calcium ions, they respond by developing highly branched dendrites, but neurons taken from mice lacking CREST fail to branch in response to calcium.

“CREST is the first example of a transcription factor—a protein that turns genes on and off—that appears to be specifically required for the development of brain neurons after birth," explains Ghosh, who conducted the study at his former laboratory at Johns Hopkins.

His new laboratory at UCSD is currently working to determine what gene is targeted by CREST. Ghosh suspects the CREST gene might be turning on the production of chemicals called growth factors, for the stimulatory effect they have on cell development.

The CREST protein produced by that gene is made in several regions of the brain immediately after birth. In adults, the protein is produced in a region of the brain known as the hippocampus, which plays an important role in learning and memory. Because of this, Ghosh suspects that CREST may be necessary for the storage of new memories and the ability to learn. His laboratory is currently developing mice in which CREST expression is normal throughout most of development, so the brain develops normally, but then shuts off in the hippocampus when the mice reach adulthood. In this way, the researchers can test the specific role of CREST in learning and memory in adults.

“Humans also have CREST, and the CREST gene sequence is highly similar between mice and humans,” says Ghosh. “If it turns out that CREST plays a role in learning and memory in the mouse, then it is very likely it also plays a similar role in humans.”

The other researchers involved in the study are Hiroyuki Aizawa, Shu-Ching Hu, Kathryn Bobb, Karthik Balakriashnan, Inga Gurevich and Mitra Cowan. The study was supported by the National Institutes of Health, the March of Dimes Birth Defects Foundation, the Klingenstein Foundation, Merck and the Uehara Memorial Foundation.


Media Contact: Sherry Seethaler (858) 534-4656
Comment: Anirvan Ghosh (858) 822-4142

Sherry Seethaler | UCSD
Further information:
http://ucsdnews.ucsd.edu/newsrel/science/screst.asp

More articles from Life Sciences:

nachricht Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory

nachricht ‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität Dresden

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>