Neurotoxins from cone snails and spiders help neurobiologists Sebastian Auer, Annika S. Strzebecher and Dr. Ines Ibaez-Tallon of the Max Delbrck Center for Molecular Medicine (MDC) Berlin-Buch, Germany, to investigate the function of ion channels in neurons. Ion channels in the cell membrane enable cells to communicate with their environment and are therefore of vital importance. The MDC researchers have developed a system which for the first time allows the targeted, long-lasting investigation of ion channel function in mammals and also the blockade of the ion channels with neurotoxins. In transgenic mice they succeeded in blocking chronic pain by introducing a toxin gene into the organism (Nature Method, doi:10.1038/NMETH.1425)*.
There are approximately 500 species of cone snails, each producing 50 200 different conotoxins. A similar number of peptide toxins are produced by snakes, spiders, sea anemones, scorpions and other venomous animals. The animals use the neurotoxins to paralyze their prey.
Scientists estimate that more than 100,000 neurotoxins exist. They have become a topic of enormous research interest: Using neurotoxins researchers can target different ion channels, receptors and other signaling molecules and characterize their physiological function.
This kind of research can also give them insight into disease processes and eventually help them to find new therapies to eventually block hyperactive ion channels. For instance, a compound (Ziconotide) based on the toxin of a cone snail is already used to treat severe chronic pain in patients.
Dr. Ibaez-Tallon's research group is concentrating on two ion channels in the membrane of neurons which are activated by electric stimulation (action potential). Once activated, they allow the influx of calcium ions into the neuron, and the cell then releases chemicals (neurotransmitters), which send the signal to the next neuron.
During the last decade
|Contact: Barbara Bachtler|
Helmholtz Association of German Research Centres