Introduction has been a part of biomedical and behavioral research for several millennia; experiments with animals were conducted in Greece over 2,000 years ago. Many advances in medicine and in the understanding of how organisms function have been the direct result of animal experimentation. Concern over the welfare of laboratory animals is also not new, as reflected in the activities of various animal welfare and antivivisectionist groups dating back to the nineteenth century. This concern has led to laws and regulations governing the use ....