Eureka moment offers neuron breakthrough
5 Oct 2009 by Evoluted New Media
Fifty years after it was originally discovered, scientists finally have an idea of the function of a microscopic network of tubules found in neurons.
Fifty years after it was originally discovered, scientists finally have an idea of the function of a microscopic network of tubules found in neurons.
For neurobiologist Thomas Oertner of the Friedrich Miescher Institute for Biomedical Research in Switzerland, this was a eureka moment: “After years of intensive research, we’ve managed to ascribe an important function to a neglected structure in nerve cells.”
Oertner’s group has described how the microscopic network of tubules known as the endoplasmic reticulum (ER) modulates the strength of connections between neurons. Neural connections play an important role in our ability to learn new information and constantly adapt to new conditions. In the brain, synaptic connections between neurons are thus continually formed, strengthened or weakened.
In addition, there are connections that remain stable – for example, when we store an important memory for many years. Connections of both types coexist, and their close proximity was one of the first key findings of Thomas Oertner’s study - the two types occur side by side on the same neuron and are individually controlled.
As the next step, Oertner’s team intends to investigate to what extent the ER-dependent process plays a role in patients with fragile X syndrome. This condition is one of the most common inherited cognitive disorders, marked by reduced intelligence, learning difficulties and attention deficits. Explaining the possible biomedical implications of his discovery, Oertner says: “We already know that patients with this syndrome have abnormal dendritic spines. We suspect that the same signaling cascade that is activated in the ER-positive spines could be over stimulated in these patients.”
The findings just published were only possible thanks to a new method known as two photon microscopy. In this imaging technique, a pulsed infrared laser is used to excite fluorescence in a dye molecule in a cell. It is a gentle method of investigating cells, which yields unique, high-resolution images.
