Improvement of memory is observed when insulin is delivered high up in the nasal cavity which then goes to the affected areas of the brain, according to a new study. This may lead to to new treatments for Alzheimer's and similar forms of dementia.
"Before this study, there was very little evidence of how insulin gets into the brain and where it goes," said William Banks, University of Washington (UW) professor of internal medicine and geriatrics.
"We showed that insulin goes to areas where we hoped it would go," said Banks, principal investigator of the study.
They found that the insulin does not go into the bloodstream when delivered intranasally. This is an import finding as there was concern that if insulin goes into the bloodstream, it might lower the blood sugar levels. Also repeated doses of insulin increased its efficiency in aiding memory.
"This is one of those studies where everything is coming together," Banks said of the potential of hormones like insulin to help those suffering from diseases like Alzheimer's that affect memory function.
A mouse model developed in the early 1990s, was used in the study, that is normal when young but by "mouse middle age" (8-12 months) has severe learning and memory problems.
In a test that depends on the mouse's natural curiosity for new things, known as the object recognition test, old mice do not remember whether objects they are presented to play with are new or old. However, after a single dose of intranasal insulin, the mice were able to remember which objects they have seen before.
Alzheimer's disease and other similar forms of dementia have become one of the most severe socioeconomic and medical burdens impacting modern society, noted researchers. The findings were published in the Journal of Alzheimer's Disease