A drug used to improve blood flow to the brain also could help reduce the risk of Alzheimer's disease, according to a new study.
For more than 10 years, Fasudil has been used to help protect the brain in stroke patients by dilating blood vessels when blood flow is curtailed.
Now, researchers at the Translational Genomics Research Institute (TGen) and Arizona State University say that hydroxyfasudil, the active form of the parent drug Fasudil, improved spatial learning and working memory in middle-aged rats when negotiating a complicated maze.
The findings suggest that hydroxyfasudil may influence similar cognitive processes in humans involving the hippocampus, a part of the brain that has been shown to deteriorate in patients with age-related disorders.
"If Fasudil proves to be safe and effective in enhancing learning and memory, it could represent a viable new option for the prophylactic treatment of disorders with a cognitive decline component. This could include diseases like Alzheimer's as well as general age-related impairment. In short, it may be a new pharmaceutical weapon that could be used even before the occurrence of symptoms," said Dr. Matthew Huentelman, an Investigator in TGen's Neurogenomics Division.
In the study, the researchers gave daily injections of hydroxyfasudil to middle-aged (17-18 months old) male rats, starting four days before behavioral testing and continuing throughout testing.
Injection made it easy to give the drug to rats, but people take it in the form of a pill.
Rats were tested on a water radial-arm maze, which assessed how well they remembered which of the radiating arms had a reward, a sign of accurate spatial learning and working memory.
Rats given a high dose (0.3750 mg per kg of weight) of hydroxyfasudil successfully remembered more items of information than those given a low dose (0.1875 mg per kg).
Both dosed groups performed significantly better than control-group rats given saline solution. On this same test, the high-dose group showed the best learning (fewest total errors) and best working memory (measured two different ways).
For every test of learning, the scores of the low-dose group fell between the scores of the no-dose and high-dose groups, meaning that learning and memory boosts depended on the size of the dose.
The study is published in today's edition of the journal Behavioral Neuroscience.