There is a kick ass paper in today's issue of the journal "Nature". Joe Z Tsien of Princeton University has used genetic engineering to create a mouse with greater intelligence than any found on Earth, it performed consistently and considerably better than any other strain in all 6 of the standard intelligence tests given to mice.
Dr. Tsien was interested in a gene that codes for part of the NMDA receptor, it comes in two forms the NR2B that is active in the young when animals are the smartest, and the NR2A which predominates in older animals. He figured that if the Hebbs rule about how the brain forms memories then this might have something to do with intelligence. Dr. Tsien put in extra copies of the gene for NR2B and control genes so that they are only expressed in the forebrain and the hippocampus. Dr. Tsien calls his new strain of mouse "Doogie" after the TV show about the 16 year old genius doctor. It's interesting that he didn't restore the intelligence of old stupid mice, he made a mouse that was smarter than any found in nature. He didn't say if old Doogie mice were smarter than old normal mice, I guess there are no old Doogie mice yet. Dr. Tsien also notes than the human version of the gene is 98% the same as that found in mice.
John K Clark firstname.lastname@example.org