Re: Doogie Mice

Patrick Wilken (
Tue, 7 Sep 1999 21:25:17 +1000

>From Bionews:

B i o N e w s 024
Week 30/8/99 - 5/9/99

1 C O M M E N T A R Y

The short answer is no!

" GENETIC SUPER BABIES STORM - Key discovery raises spectre of designer children with high IQs" is how the Daily Mail announced the report of enhanced learning and memory in mice with over-expressed NMDA 2B receptors, the lead story in BioNews this week. A few weeks back I argued in a BioNews commentary that we are going to have to live with less than satisfactory headlines as genetic approaches revolutionise research into behaviour. The temptation of the catchy headline is just too great. But by any standards, the above headline is an extraordinary 'non sequitur'.

Prolonging (into adulthood) the higher level of learning and memory that normally occurs in young mice by genetically engineered over-expression of a receptor on brain cells in laboratory mice is an important research result. It is one more piece of evidence in support of a 50-year old hypothesis on how learning and memory occurs in the mammalian brain. How directly this result will help biomedical research into human learning impairments or severe memory loss associated with old age is not clear at this stage. What is clear is that no research equals no progress in tackling these handicaps. Other recent work in mice (Mohn et al Cell 98,427-436.1999) suggests that another component of the NMDA receptor is highly relevant to understanding schizophrenia.

Will all transgenic research in laboratory animals from now on 'raise the spectre of designer babies'? In the Daily Mail's defence they did carry a quote (an unfortunate one in my opinion) from Dr Vivienne Nathanson, head of ethics at the British Medical Association. She is quoted as saying 'S. This discovery leads to the spectre of designer babies and the concept of children being rejected because they do not have these qualities'. Why should it? Society is capable of drawing lines and does so all the time. There is a pretty large gap between research in mice aimed at understanding how the brain works and attempts to genetically modify human embryos during IVF. The first doesn't, in anyway, merge with the second. In any case, genetically modifying human embryos is illegal in the UK.

If anything, the NMDA receptor research will lead to specific drugs aimed at treating serious mental disorders. At most this might raise the spectre of drug abuse by people trying to enhance their mental powers. The discovery of the growth-enhancing effects of steroids has led to cheating in athletics, but it has hardly created a 'super designer babies storm'.

2 N E W S D I G E S T

Changing a single gene is enough to improve learning and memory, US scientists report in the journal Nature. Neurobiologist Joe Tsien, in collaboration with researchers at MIT and Washington University, found that adding a single gene to mice significantly boosted the animals' ability to solve maze tasks, learn from objects and sound in their environment and to retain that knowledge. This strain of mice, named Doogie after the teenage genius in the eponymous American television show, also retained into adulthood certain brain features of juvenile mice - which, like young humans, are believed to be better than adults at grasping large amounts of new information.

The work is a breakthrough in memory research and reveals a common biochemical mechanism to be at the root of nearly all learning. A gene called NR2B appears to be the switch that controls the brain's ability to associate one event with another - the core feature of learning. Tsien had previously created mice that lacked the gene in a tiny region of the brain and showed that they had impaired learning and memory. Adding new or improved function, however, is a harder task and a more rigorous test of the gene's function.

The research showed that the enhanced learning and memory abilities of the Doogie strain of mice were the result of an over-expression of a particular protein sub-unit of the NMDA receptors in the brain. Now that the precise role of this brain protein is known, drug companies could design drugs that could improve learning and boost memory in people suffering from age-related disorders such as Alzheimer's.

However, some commentators as well as the researchers themselves have brought up another possible application of the research - gene therapy on babies to overcome inherited disorders or just boost intelligence. Although enthusiastic about the research, British neuroscientists were dismissive about claims of enhancing intelligence. 'This is a real piece of vulgar hype from Princeton,' said Steven Rose, head of the brain and behaviour group at the Open University. 'They shouldn't do this stuff, it really is irresponsible... Human intelligence is something that develops as part of the interaction between children and the social and natural world, as they grow up. It is not something locked inside a little molecule in the head.'

Patrick Wilken
Editor:        PSYCHE: An International Journal of Research on Consciousness
Board Member:      The Association for the Scientific Study of Consciousness