The ethics of research involving animals - Nuffield Council on ...
The ethics of research involving animals - Nuffield Council on ...
The ethics of research involving animals - Nuffield Council on ...
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T h e e t h i c s o f r e s e a r c h i n v o l v i n g a n i m a l s<br />
a living animal (usually a rodent). This is because those who undertake such <str<strong>on</strong>g>research</str<strong>on</strong>g> believe<br />
that this procedure is the most scientifically valid, and <str<strong>on</strong>g>of</str<strong>on</strong>g>ten the <strong>on</strong>ly way <str<strong>on</strong>g>of</str<strong>on</strong>g> determining<br />
horm<strong>on</strong>e functi<strong>on</strong> in physiology and development. <str<strong>on</strong>g>The</str<strong>on</strong>g> welfare implicati<strong>on</strong>s for the <str<strong>on</strong>g>animals</str<strong>on</strong>g><br />
involved will vary depending <strong>on</strong> the kind <str<strong>on</strong>g>of</str<strong>on</strong>g> horm<strong>on</strong>e and the dose administered. In humans,<br />
horm<strong>on</strong>al imbalances can cause unpleasant symptoms, including lethargy and headaches.<br />
Box 5.3: Example <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>research</str<strong>on</strong>g> – How do<br />
m<strong>on</strong>keys view faces?<br />
Guo K, Roberts<strong>on</strong> RG, Mahmoodi S et al. (2003) How do<br />
m<strong>on</strong>keys view faces? – a study <str<strong>on</strong>g>of</str<strong>on</strong>g> eye movements Exp<br />
Brain Res 150: 363–74.*<br />
Percepti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> faces plays a crucial role in social<br />
communicati<strong>on</strong>. <str<strong>on</strong>g>The</str<strong>on</strong>g> aim <str<strong>on</strong>g>of</str<strong>on</strong>g> this <str<strong>on</strong>g>research</str<strong>on</strong>g> was to study<br />
accurately how faces are viewed by primates. <str<strong>on</strong>g>The</str<strong>on</strong>g><br />
<str<strong>on</strong>g>research</str<strong>on</strong>g>ers investigated the organisati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> eye<br />
movements in two adult male rhesus macaque m<strong>on</strong>keys<br />
in resp<strong>on</strong>se to facial images. Previous studies had<br />
suggested similarities between humans and m<strong>on</strong>keys in<br />
the neural mechanisms resp<strong>on</strong>sible for the percepti<strong>on</strong><br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> faces. Thus, it was c<strong>on</strong>cluded that the results <str<strong>on</strong>g>of</str<strong>on</strong>g> this<br />
study could be compared to findings obtained from<br />
humans by less invasive means.<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> m<strong>on</strong>keys underwent an operati<strong>on</strong> under<br />
anaesthesia to implant a head-restraint device (see<br />
paragraph 4.47). Coils were then surgically implanted<br />
into the white, outer layer <str<strong>on</strong>g>of</str<strong>on</strong>g> the eyeball (the sclera) so<br />
that eye movements could be recorded. During<br />
experiments, the m<strong>on</strong>keys were seated in ‘primate<br />
chairs’ (see also Box 5.5), which enable the head <str<strong>on</strong>g>of</str<strong>on</strong>g> the<br />
m<strong>on</strong>key to be fixed. <str<strong>on</strong>g>The</str<strong>on</strong>g> m<strong>on</strong>keys’ eye positi<strong>on</strong>s were<br />
recorded while images <str<strong>on</strong>g>of</str<strong>on</strong>g> m<strong>on</strong>key and human faces<br />
were presented <strong>on</strong> a computer screen.<br />
It was already known that when m<strong>on</strong>keys are shown<br />
faces <str<strong>on</strong>g>of</str<strong>on</strong>g> other m<strong>on</strong>keys, their eyes fix <strong>on</strong> the eyes in the<br />
image. This particular experiment investigated the<br />
visual process that occurs when the faces were<br />
unfamiliar to the m<strong>on</strong>keys, and when the images were<br />
inverted or scrambled. Differences in perceptual<br />
processing when either a m<strong>on</strong>key or a human face was<br />
shown were also assessed. It was found that the<br />
m<strong>on</strong>keys exhibited similar eye scan patterns while<br />
viewing both familiar and unfamiliar m<strong>on</strong>key faces, or<br />
while viewing m<strong>on</strong>key and human faces. <str<strong>on</strong>g>The</str<strong>on</strong>g>re was a<br />
greater incidence <str<strong>on</strong>g>of</str<strong>on</strong>g> fixati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> the eye regi<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> all the<br />
face images, and particularly re-fixati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> the eyes <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
unfamiliar faces during the first few sec<strong>on</strong>ds,<br />
c<strong>on</strong>firming that the eyes are important for initial<br />
identificati<strong>on</strong>. However, it was found that the eyes in<br />
the scrambled face images were much less <str<strong>on</strong>g>of</str<strong>on</strong>g> a focus<br />
than those in the upright or inverted faces. <str<strong>on</strong>g>The</str<strong>on</strong>g><br />
<str<strong>on</strong>g>research</str<strong>on</strong>g>ers c<strong>on</strong>cluded that, while viewing faces, the eye<br />
movements in n<strong>on</strong>-human primates are c<strong>on</strong>trolled by<br />
more than <strong>on</strong>e level <str<strong>on</strong>g>of</str<strong>on</strong>g> perceptual processing; i.e. that<br />
the targeting <str<strong>on</strong>g>of</str<strong>on</strong>g> the eye regi<strong>on</strong> may occur at a relatively<br />
low level <str<strong>on</strong>g>of</str<strong>on</strong>g> visual processing (before identificati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
the object) and that the probability that the eyes will<br />
become the eventual target in the image is affected by<br />
higher levels.<br />
With regard to welfare implicati<strong>on</strong>s, the implants could<br />
have caused discomfort; the m<strong>on</strong>keys would also have<br />
needed to be carefully trained to avoid psychological<br />
distress caused by the restraint during the experiment.<br />
No reinforcements in the form <str<strong>on</strong>g>of</str<strong>on</strong>g> ‘rewards’ or<br />
‘punishments’ were given during this procedure.<br />
* This is an example <str<strong>on</strong>g>of</str<strong>on</strong>g> animal <str<strong>on</strong>g>research</str<strong>on</strong>g> that has been carried<br />
out in the UK and published in a peer-reviewed journal.<br />
Details relate to this specific example and should not be taken<br />
to represent a ‘typical’ animal experiment. It is important to<br />
note that individually published experiments usually form <strong>on</strong>e<br />
part <str<strong>on</strong>g>of</str<strong>on</strong>g> a c<strong>on</strong>tinuing area <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>research</str<strong>on</strong>g>, and the significance <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
the results may therefore be difficult to interpret.<br />
Study <str<strong>on</strong>g>of</str<strong>on</strong>g> the immune system<br />
5.7 Many studies <strong>on</strong> living <str<strong>on</strong>g>animals</str<strong>on</strong>g>, <str<strong>on</strong>g>involving</str<strong>on</strong>g> mainly mice and rats, have been c<strong>on</strong>ducted to<br />
examine the vertebrate immune system, and most current knowledge is based <strong>on</strong> this<br />
<str<strong>on</strong>g>research</str<strong>on</strong>g>. <str<strong>on</strong>g>The</str<strong>on</strong>g> immune systems <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>animals</str<strong>on</strong>g> and humans protect them from infecti<strong>on</strong>. If the<br />
adaptive immune system is challenged by a particular infectious agent that it has previously<br />
overcome, it is able to do so <strong>on</strong> subsequent occasi<strong>on</strong>s much more quickly and effectively.<br />
Research <strong>on</strong> the adaptive immune system usually involves an initial immunisati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>animals</str<strong>on</strong>g><br />
with foreign (from another animal) biological molecules or cells or microorganisms such as<br />
bacteria. Immune resp<strong>on</strong>ses are characterised by the producti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> immune cells and<br />
antibodies, which specifically recognise and help eliminate the foreign molecules, cells or<br />
microorganisms (all referred to as antigens). Experiments <str<strong>on</strong>g>of</str<strong>on</strong>g> this kind provided the first<br />
evidence that the cells resp<strong>on</strong>sible for adaptive immune resp<strong>on</strong>ses were a class <str<strong>on</strong>g>of</str<strong>on</strong>g> white<br />
blood cells called lymphocytes. In these experiments, rats or mice were irradiated with X-rays<br />
to kill most <str<strong>on</strong>g>of</str<strong>on</strong>g> their white blood cells, including lymphocytes, rendering them unable to<br />
make adaptive immune resp<strong>on</strong>ses. When different cell types were transferred into these<br />
<str<strong>on</strong>g>animals</str<strong>on</strong>g>, <strong>on</strong>ly lymphocytes were found to reverse this deficiency. <str<strong>on</strong>g>The</str<strong>on</strong>g> welfare <str<strong>on</strong>g>of</str<strong>on</strong>g> the <str<strong>on</strong>g>animals</str<strong>on</strong>g><br />
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