Though it's most often associated with disorders like diabetes, Harvard researchers have shown how the signaling pathway of insulin and insulin-like peptides plays another critical role in the body helping to regulate learning and memory.
In addition to showing that the insulin-like peptides play a critical role in regulating the activity of neurons involved in learning and memory, a team of researchers led by Yun Zhang, Associate Professor of Organismic and Evolutionary Biology, show that the interaction between the molecules can fine-tune how, or even if, learning takes place. Their work is described in a February 6 paper in Neuron.
"People think of insulin and diabetes, but many metabolic syndromes are associated with some types of cognitive defects and behavioral disorders, like depression or dementia," Zhang said. "That suggests that insulin and insulin-like peptides may play an important role in neural function, but it's been very difficult to nail down the underlying mechanism, because these peptides do not have to function through synapses that connect different neurons in the brain"
To get at that mechanism, Zhang and colleagues turned to an organism whose genome and nervous system are well described and highly accessible by genetics C. elegans.
Using genetic tools, researchers altered the small, transparent worms by removing their ability to create individual insulin-like compounds. These new "mutant" worms were then tested to see whether they would learn to avoid eating a particular type of bacteria that is known to infect the worms. Tests showed that while some worms did learn to steer clear of the bacteria, others didn't suggesting that removing a specific insulin-like compound halted the worms' ability to learn.
Researchers were surprised to find, however, that it wasn't just removing the molecules that could make the animals lose the ability to learn some peptide was found to inhibit lea
|Contact: Peter Reuell|