Science
Useless experiments
Bernard Dixon
A scientist at the University of Oregon recently decided to investigate grooming behaviour In mice. He wanted to find out to what degree the character istic movements made by mice when grooming the face were inherited, and to what extent learned from or influenced by the outside world.
The method used by the Oregon researcher was as follows. He studied six litters of mice, each consisting of seven to nine animals, some of whose forelimbs he amputated. In each litter one to three mice had one forelimb severed on the day after birth, and one to three of the remainder had both forelimbs cut off. The mice were anaesthetised, and the limbs sectioned between the elbow and shoulder with a scalpel, and treated with ferric sub-sulphate to curb bleeding. The researcher then observed all of the mice, normal and defective, regularly until they were thirty days old, and periodically afterwards for up to five months. A film camera recorded their grooming movements, and these have now been analysed in the journal Science. Two of the operated mice died, for reasons unstated, before the end of the experiment.
The published conclusion of the investigation was that "face grooming sequences that involve co-ordination of the shoulders, tongue and eyes develop remarkably normally in inbred mice with one or both forelimbs amputated from birth. This indicates endogenous control with a strong genetic component." Normal mice lick their forepaws by extending the tongue as they bring their paws towards the face by rotating their shoulders in a particular way. The amputated mice made every effort to do likewise. Their tongue and shoulder movements were obviously co-ordinated even though in their case this meant that the limb stubs were moving away from the tongue when it was extended.
Moreover, "one 'further striking, and unexpected, characteristic of licking occurred reliably in the amputated animals. These animals, deprived of normal contact between the forepaws and the tongue, would often introduce, interrupt or conclude a grooming sequence with periods of licking the cage floor, cage sides, or even another mouse." The Oregon researcher deduced from this that the mouse brain " expected " a feedback of tactile sensation during grooming.
I record this investigation with some distaste — though emphatically not as one who automatically takes a hostile line on the use of animals in research. Indeed, I write as a former research scientist, who 15 often irritated by sensational misrepresentations of animal experiments put about by extremists of the anti-vivisection lobby. Sadly but certainly, animal experimentation has long been necessary in furthering medical research, diagnosis and treatment. While we should be doing considerably more than at present to develop alternative techniques where these are feasible, there are many areas — not least the prevention of another thalidomide tragedy — where animal experimentation is still vitally necessary. But this is entirely different from defending all such experiments, and from time to time in the scientific journals I find reports of work which is very difficult indeed to justify. The Oregon experiment comes into that category.
The phenomenon of instinctive behaviour is, of course, a fascinating topic and a legitimate one for scientific analysis. We have no evidence that the research worker in this case was wilfully cruel. And there is always the possibility that lessons learned in the investigation could be practically useful to man — they could be relevant to certain types of mental illness, for example. So one criticises with caution. Nonetheless, bearing in mind the merits and demerits of the experiment, the availability of alternative approaches to the same general problem, and above all the wider ethical issue, I cannot see that such experiments are justified. They would probably not be allowed in Britain. Let us be thankful for that.