Of the 98 Nobel Prizes awarded for Physiology or Medicine, 75 were directly dependent on research from animals. In a further four instances no animal experiments were performed by the prize winner, but the discovery relied on crucial data obtained from animal studies by other research groups.

The most recent use of primates in Nobel Prize winning research occurred in 1981; Roger W. Sperry, David H. Hubel and Torsten N. Wiesel were awarded the coveted award for their work exploring brain function. By studying monkeys, Roger W. Sperry found that the nerves connecting the left and right hemispheres of the brain could be severed without causing any drastic changes in the monkeys; each side of the brain was still able to learn, however, what was learned by one side could no longer be retrieved by the other.

Biologists believe that chimpanzees share at least 98.4 percent of the same DNA as humans while the genetic composition of gorillas is at least 97 percent consistent with that of humans. Evidence of all animals and primates in particular as "sentient" beings, capable of a range of emotions and thought processes, has led scientists to search for alternative ways to study behavior without victimizing animals.


Greeks, Arabs, Romans

In ancient times, scientists made use of animals principally to satisfy anatomical curiosity. Early Greek physician-scientists performed experiments on living animals. Herophilus and Erasistratus, for example, examined sensory nerves, motor nerves, and tendons in order to understand their functional differences.

Galen of Pergamum, a Greek physician who practiced in Rome during the 2nd century, conducted animal experiments in the areas of anatomy, physiology, pathology, and pharmacology; he is the first to describe the complexities of the cardio-pulmonary system, and he also speculated on brain and spinal cord function. In De Anatomicis Administrationibus (On Anatomical Procedures) he detailed precise experimental methods and identified the best instruments to perform specific procedures. As anaesthetics were not discovered until the mid-nineteenth century, his experiments were conducted without benefit of pain management.

An Arab physician of the 12th Century, Ibn Zuhr (or Avenzoar) tested surgical procedures on animals before applying them to human patients. Interest in anatomy and scientific methods was reawakened when Galen's records were rediscovered during the sixth century. At that time, scientists often conducted experiments as public demonstrations; such was the case with Andreas Vesalius (1514-1564) and his students in Padua, Italy. By use of systemic vivisection, Vesalius would demonstrate anatomy. A live animal, usually a dog, would be cut open and, as each organ was located, the students would speculate upon the function. One of Vesalius' pupils, Realdo Colombo, pulled a fetus out of a dog's womb and, hurting the newly born pup in front of its mother's eyes, he provoked furious barking. Next he held the pup to the bitch's mouth; licking it tenderly, the bitch showed more concern for her offspring than her own suffering. When something other than the puppy was held in front of her mouth, the bitch snapped in rage. Those observing expressed their pleasure in this example of motherly love even in a 'brute creation.'


The Recent Past

For the United States, use of animals in research, particularly when it came to pharmaceutical drug testing, became extremely important to citizens of the twentieth century. In 1937, a pharmaceutical company created a preparation of sulfanilamide, a drug used to treat streptococcal infections, by using diethylene glycol (DEG) as a solvent. Unknown to the chemist, DEG was poisonous to humans, but he simply added raspberry flavoring and marketed the product as 'Elixir Sulfanilamide.' The preparation led to mass poisoning causing the deaths of more than a hundred people. The public outcry caused by this incident and similar disasters led to the passing of the 1938 Federal Food, Drug, and Cosmetic Act requiring safety testing of drugs on animals before they could be marketed.

Despite the regulations, the tragedy of thalidomide in the late 1950s and early 1960s occurred. Proclaimed to be a 'wonder drug' for insomnia, coughs, colds, and headaches, it was also found to have an inhibitory effect on morning sickness and so was prescribed to thousands of pregnant women. Consequently, more than 10,000 children in 46 countries were born with malformations or missing limbs.


Today: The Three Rs

These descriptions of the earliest scientific experiments are sobering and raise numerous questions of ethics. Scientists, though, resolve their doubts by following a set of principles.

Aware of the potential importance of their work and how a system can lend insight into how to prevent and cure illness, scientists follow the three Rs in order to reduce the impact of research on animals: Reduction, Refinement, Replacement.

  • Reduction: Reducing the number of animals used in experiments by:
    • Improving experimental techniques
    • Improving techniques of data analysis
    • Sharing information with other researchers
  • Refinement: Refining the experiment or the way the animals are cared for so as to reduce their suffering by:
    • Using less invasive techniques
    • Better medical care
    • Better living conditions
  • Replacement: Replacing experiments on animals with alternative techniques such as:
    • Experimenting on cell cultures instead of whole animals
    • Using computer models
    • Studying human volunteers
    • Using epidemiological studies

At different periods and for a variety of reasons, scientists also simply choose to abstain from the use of animals in experiments.


The Future: Harvard and the NIH Lead the Way

Earlier this year, Harvard Medical School announced it would shut down its primate research center by 2015. The announcement surprised many outside researchers, because it comes a year and a half after Harvard began investing significant time and resources into the research center, to correct animal care and oversight problems that had resulted in the deaths of four monkeys between June 2010 and Feb. 2012. The U.S. Department of Agriculture had investigated the center and cited Harvard for violations of animal welfare rules. Medical school leaders said the decision was unrelated to its previous problems and cited economic difficulties and shifting long-term strategic plans.

Nancy Haigwood, director of the Oregon National Primate Research Center, told the Boston Globe the decision would, at the least, slow down the pace of research into diseases that affect human health and might lead scientists to leave the Boston area to pursue their projects. The primate center is known for its research on infectious diseases, such as AIDS, and neurodegenerative diseases such as Parkinson's disease.

Meanwhile, the National Institutes of Health (NIH) announced its own plans to reduce the use of chimpanzees in NIH-funded biomedical research and so will 'retire' most of the chimpanzees it currently owns or supports. NIH plans to retain but not breed up to 50 chimpanzees for future biomedical research. Only those research projects that meet the Institute of Medicine's principles and criteria will find NIH chimpanzees available for use. The retiring chimpanzees may join the more than 150 other chimpanzees already in the Federal Sanctuary System.

"Their likeness to humans has made them uniquely valuable for certain types of research, but also demands greater justification for their use," said NIH Director Francis S. Collins, M.D., Ph.D.


Source: Hajar R. Animal Testing and Medicine. Heart Views : The Official Journal of the Gulf Heart Association. 2011.