Researchers find a key mechanism in the development of nerve cells

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Researchers find a key mechanism in the development of nerve cells

http://www.eurekalert.org/pub_releases/2009-09/uoh-rfa092909.php

Chaos brews in the brains of newborns: the nerve cells are still bound only

loosely to each other. Under the leadership of Academy Research Fellow Sari

Lauri, a team of researchers at the University of Helsinki has been studying for

years how a neural network capable of processing information effectively is

created out of chaos. The team has now found a new kind of mechanism that

adjusts the functional development of nerve cell contacts. The results were

published in early September as the leading article of the esteemed Journal of

Neuroscience.

The work carried out by Lauri's team and its partners at the Viikki campus sheds

light on a development path that results in some of the large number of early

synapses becoming stronger. The researchers found out hat the BDNF growth factor

of nerve cells triggers a functional chain which promotes the release of the

neurotransmitter glutamate. BDNF enables the release of glutamate by prohibiting

the function of kainate receptors which slow down the development of the

preforms of the synapses. The activity of the kainate receptors restricts the

release of glutamate and the development of synapses into functional nerve cell

contacts.

It is noteworthy that the brain of a newborn itself seems to organise its own

development. The electrical activity of the waking brain triggers the series of

events controlled by the BDNF protein, as a result of which kainate receptor

activity disappears in some synapses. The development is based on the

considerable plasticity of the developing neural network: it can reshape its

structureand function to a large extent.

According to Lauri, the new research results help understand how central nervous

system diseases originating in early development are established. The finding

also provides researchers with the opportunity to obtain information about the

different aspects of endogenous activity of the brain. At the same time, it

could be possible to develop new kinds of pharmaceuticals for the treatment of

childhood epilepsy, for example.

Lauri's team conducted the research in co-operation with the research teams of

Eero Castren and Tomi Taira from the Neuroscience Centre, and the research team

of Jari Yli-Kauhaluoma from the Faculty of Pharmacy.