14 DAY TRIAL // Nerve cells store and transmit information via special contact sites called synapses. Synapses also play a role in determining what we remember and what we forget.
When we learn both the structure and the functional characteristics of these contact sites change. Scientists are only now beginning to understand the molecular processes which cause that change.
A team of researchers led by Michael Kiebler at the Max Planck Institute for Developmental Biology has identified a protein that is essential for the maintenance of synapses, namely the protein Staufen2, whose removal leads to the loss of a large portion of the synapses.
Staufen proteins are involved in the transport of molecular blueprints (mRNAs) to specific locations in a cell. The disturbance in the structure and function of synapses without Staufen2 protein suggests that mRNA transport to synapses is crucial to their maintenance and the storage of memory.
Nerve cells receive signals from other nerve cells via dendrites, which branch out like the branches of a tree. The cell-body receives incoming information, and transmits it further through the axon. Nerve cells make contact with each other at highly-specialized locations known as synapses, where the information is not only passively transmitted, but also, depending on input, stored into memory.
If the brain-specific Staufen2 protein was missing, the architecture of the synapses was severely disturbed. Instead of a number of mushroom-shaped dendritic spines, the cell only produced long, thin protuberances, similar in shape to immature synapses
Measurements of electrical activity at individual synapses showed impaired signal transmission in cells lacking the Staufen2 protein.
"We wanted to know if Staufen2-deficient nerve cells can still transmit signals. This was important evidence that Staufen2 is necessary for the formation of functional synapses in nerve cells," study author Michael Kiebler explained.
This discovery could lead to a better understanding of molecular mechanisms, which lie at the heart of the brain's ability to learn and to remember.