Switching on the Smart Gene
Photo via flickr by mandykoh
Over-expressing a gene that lets brain cells communicate just a fraction of a second longer makes a smarter rat, report researchers from the Medical College of Georgia and East China Normal University.
Dubbed Hobbie-J after a smart rat that stars in a Chinese cartoon book, the transgenic rat was able to remember novel objects, such as a toy she played with, three times longer than the average Long Evans female rat, which is considered the smartest rat strain. Hobbie-J was much better at more complex tasks as well, such as remembering which path she last traveled to find a chocolate treat.
The report comes about a decade after the scientists first reported in the journal Nature that they had developed “Doogie,” a smart mouse that over-expresses the NR2B gene in the hippocampus, a learning and memory center affected in diseases such as Alzheimer’s. Memory improvements they found in the new genetically modified Long Evans rat were very similar to Doogie’s. Subsequent testing has shown that Doogie maintained superior memory as he aged.
“This adds to the notion that NR2B is a universal switch for memory formation,” says Dr. Joe Z. Tsien, co-director of the MCG Brain & Behavior Discovery Institute and co-corresponding author on the paper published in PLoS ONE. Dr. Xiaohua Cao at East China Normal University also is a co-corresponding author.
The finding also further validates NR2B as a drug target for improving memory in healthy individuals as well as those struggling with Alzheimer’s or mild dementia, the scientists says.
Scientists found that Hobbie-J consistently outperformed the normal Long Evans rat even in more complex situations that require association, such as working their way through a water maze after most of the designated directional cues and the landing point were removed. “It’s like taking Michael Jordan and making him a super Michael Jordan,” Deheng Wang, MCG graduate student and the paper’s first author, says of the large black and white rats already recognized for their superior intellect.