Insulin May Treat and Prevent Alzheimer's Disease
A research team from Northwestern University has found that insulin may combat Alzheimer's disease by protecting brain synapses from harm. After emerging theories that Alzheimer's may actually be a third form of diabetes, this new relationship between Alzheimer's and insulin treatment provides compelling evidence toward the link between diabetes and dementia.
In a study of neurons taken from the hippocampus, one of the brain's crucial memory centers, the scientists treated cells with insulin and the insulin-sensitizing drug rosiglitazone, which has been used to treat type 2 diabetes. (Isolated hippocampal cells are used by scientists to study memory chemistry; the cells are susceptible to damage caused by ADDLs, toxic proteins that build up in persons with Alzheimer's disease.)
The researchers discovered that damage to neurons exposed to ADDLs was blocked by insulin, which kept ADDLs from attaching to the cells. They also found that protection by low levels of insulin was enhanced by rosiglitazone.
ADDLs (short for "amyloid beta-derived diffusible ligands") are known to attack memory-forming synapses. After ADDL binding, synapses lose their capacity to respond to incoming information, resulting in memory loss.
If synapses can be protected from the deteriorating effects of AADLs then the onset of memory loss might be prevented or prolonged. The findings will be published in the Proceedings of the National Aceademy of Sciences journal.