In the news
6 Sep 2008
16 August 2007
Animal-free pain research advanced with PhD studentship
The Dr Hadwen Trust has announced the award of a new PhD studentship at Birmingham’s Aston University, to be known as the Alan & Kathie Stross Research Award. This exciting development signals our support for the training of a young scientist from the pharmaceutical industry, in the use of non-animal research techniques to study the human brain and replace animal experiments. Her research project will study pain and pain relief drugs in human volunteers using two types of non-invasive brain imaging techniques, MRS (magnetic resonance spectroscopy) and MEG (magnetoencephalography).
Animal experiments are widely used to investigate pain and to test new pain relief drugs. Pain is induced in animals by injections of irritant chemicals, applying extreme cold or heat, or damaging nerves. Most commonly rodents are used in experiments, but sometimes monkeys too. Due to differences between species, animals suffer to produce results that are of unknowable relevance to humans and which cannot accurately be applied to patients. As a result, very few drugs tested on animals become useful medicines for humans.
As part of our Science Without Suffering report, we highlighted recent pain research experiments at British establishments where pain was purposely inflicted on rodents. For example, in one study rats had breast cancer cells injected into their limb bones causing fast-growing, painful tumours and extensive bone damage. These gruesome experiments lasted for over 20 days and resulted in the animals being extremely sensitive to pain caused by the slightest touch to their damaged limbs1 .
In a separate study2, the chemical MIA (mono-iodoacetate) was injected into rats’ knees, causing the breakdown of joint cartilage and destruction of the leg bone. These experiments used 400 animals, some of whom were left to suffer these painful symptoms for 35 days, with no pain relief. Others were dosed with painkillers to study the nature of their pain experience, but one drug had no effect and these rats suffered a full 28 days with no relief from their pain. After 14 days, researchers found serious ulceration of the cartilage and bone in the rats’ knees and after 21 days, the animals suffered deep bone damage. Additionally, the joint damage caused injury to nerves close to the spine, inflicting yet another kind of pain. Rats enduring painful joint and nerve damage were made to stand so that researchers could observe to what extent they were limping.
Self-evidently, these are experiments that involve the deliberate infliction of substantial pain and suffering in animals, and therefore a high priority for replacement for the Dr Hadwen Trust. Additionally, animals do not make appropriate models of human pain which is a very complex and subjective experience. Notable species differences have been found between rodents and humans in key receptors involved in pain processing. Different species handle drugs differently and painkilling drugs can have widely varying effects in different animals. Not only are there significant species differences, but human studies are also revealing gender variations in pain processing, and painkillers appear to work differently in men and women.
Non-invasive brain imaging techniques that allow the direct study of the human brain are already helping to replace experiments on rodents and primates. Our new research project at Aston builds on that work by devising new methods of safely studying the effects of medicines on the human brain to see how pain relief drugs work in humans, and to replace current animal studies. Through brain imaging in volunteers, the researcher will be able to identify the areas of the brain involved in different types of pain processing, the parts of the brain affected by analgesics, and the duration of these effects. One of the major advantages of these safe and non-invasive methods, is that volunteers will be able to directly communicate their experience of pain and pain relief in a way that is impossible with animal experiments.
NOTES:
1 A rat model of bone cancer pain. Pain, 2002, 96(1-2):129-140.
2 Structural pathology in a rodent model of osteoarthritis is associated with neuropathic pain: Increased expression of ATF-3 and pharmacological characterisation. Pain, 2007, 128(3): 272-282.
