Animal Aid

Primate Experiments: The Painful Reality

In a shocking new dossier, Animal Aid reveals how monkeys are made to suffer and die inside British laboratories and the ‘reasons’ given for their deaths. All the experiments revealed in the dossier took place in Britain (apart from one which was conducted in the USA with a British scientist) in the past two years and were published in 2006. The experiments include monkeys being deliberately brain damaged and then frightened, in order to assess their responses, and a 16-year old macaque being dosed with a drug that induces tremors, rigidity and incapacity.

Around 10,000 primates are used in laboratories across Europe every year, with a third of them being experimented upon in British laboratories. This makes Britain the monkey-killing capital of Europe. Aside from the physical suffering, monkeys experience fear, loneliness, frustration and stress, simply from being kept in captivity.

Now, there is a chance to end primate experiments through legislation currently working its way through the European Parliament. Directive 86/609 is intended to update welfare laws for animals in laboratories but will not bring about an end to all animal experimentation. It does, however, offer the possibility of a ban on the use of primates. The demand for such a ban has already attracted the support of nearly 250 legislators across Europe, as well as leading academics, scientists and 95 animal protection groups.

Oxford: Brain damage in monkeys increases their fear of toy snakes

A team of researchers in the Department of Experimental Psychology at Oxford University investigated the effects of brain damage on the social behaviour of nine macaque monkeys.

The monkeys were divided into three groups - each having different parts of their brains surgically damaged. Once the animals had regained consciousness, they were studied to see how they responded to various threatening situations. This included being exposed to rubber snakes and the stares of unfamiliar human faces.

Primates reach out at touch each other from behind cages

Similar previous experiments conducted by the same researchers had shown that the greater the brain damage, the less sociable the monkeys became with one another. The team did not reveal the fate of the monkeys after the experiment.

In conclusion, the researchers made a tacit admission about the lack of relevance of their own research. They stated that the equivalent tests given to human subjects (for which non-invasive scanning equipment was used) were considerably more complex than those possible in monkeys.

Rudebeck M, Buckley MJ, Walton ME, Rushworth MFS. Science 2006; 313:1310-1312. 'A role for the macaque anterior cingulate gyrus in social valuation.'

Manchester: Monkey brains are unique

Primate being held

Scientists in the Faculty of Life Sciences of Manchester University conducted a series of experiments to compare the way in which cells are arranged in the brains of marmoset and macaque monkeys.

Four young marmosets were anaesthetised before having the skin and muscle on their heads peeled back to expose their skulls. A stainless steel recording chamber was secured to the skull using dental cement.

The anaesthetised monkeys were exposed to a series of optical experiments lasting from 60 to 72 hours, during which they were fed by intravenous infusion. At the end of the experiment, all of the animals were killed with a lethal injection.

The researchers concluded that there are similarities as well as differences in the way cells in the vision area of the brain are arranged in marmoset monkeys compared with macaques. The relevance to human health remains unknown.

Funded in part by the Wellcome Trust.

McLoughlin N, Schiessl I. NeuroImage 2006; 31:76-85. 'Orientation selectivity in the common marmoset (Callithrix jacchus): the periodicity of orientation columns in V1 and V2.'

Porton Down: Marmoset monkeys used by MoD to disprove 'Gulf War Syndrome'

Following active service during the 1991 Gulf War, a number of UK veterans complained of a diverse range of symptoms, collectively known as Gulf War Syndrome (GWS). Despite official findings in 2004, by the US Research Advisory Committee, linking GWS to chemical exposure, the UK Ministry of Defence continues to deny the link, based in large part on the results of government-funded animal research.

This study - conducted at Porton Down in 2005 - exposed 48 marmoset monkeys to an intensive schedule of blood sampling, surgical procedures, anti-nerve agent administration, multiple vaccinations, daily cognitive tests and weekly strength tests.

The experiment lasted 21 months, at the end of which the monkeys were killed for tissue analysis. Only 32 monkeys completed the study - out of an original number of 48. The fate of the other 16 monkeys went unrecorded.

Stevens D, Scott EAM, Bowditch AP, Griffiths GD, Pearce PC. Pharmacology, Biochemistry and Behaviour 2006; 84:207-218. 'Multiple vaccine and pyridostigmine interactions: effects on cognition, muscle function and health outcomes in marmosets.'

Funded by the Veterans Policy Unit

GSK, Harlow, Essex: Monkeys pickled alive

Researchers at King's College London, in collaboration with GlaxoSmithKline (Harlow, Essex) used eight marmoset monkeys to investigate Parkinson's disease. The animals had been given a drug called MPTP over a period of 18 months prior to the start of the actual experiment. MPTP is a chemical that artificially induces Parkinson-like tremors. Depending on the dose, monkeys experience varying degrees of incapacity, tremors, rigidity and loss of voluntary body movements.

At the end of the study, all eight monkeys were killed for laboratory examination. Half were killed by lethal injection. The other four were anaesthetised and 'pickled' while still alive, using a transfusion of highly toxic embalming fluid that ultimately killed them. This method of preserving animals exploits the fact that the still beating heart can better circulate the embalming fluid throughout the entire body.

Zeng B-Y, et al. European Journal of Neuroscience 2006; 23:1766-1774. 'MPTP treatment of common marmosets impairs proteasomal enzyme activity and decreases expression of structural and regulatory elements of the 26S proteasome.'

Funded by GlaxoSmithKline Pharmaceuticals and Rosetrees Trust

Oxford, Cambridge and Newcastle: Brain-damaged monkeys forced to watch fish

Scientists from the Universities of Oxford, Cambridge, Newcastle and the University of Western Ontario (Canada) teamed up to conduct a long-term study of brain behaviour in two male macaque monkeys. Both monkeys underwent brain surgery to implant electrodes, which recorded brain activity. The implant was held in place by stainless steel screws, a head bolt and dental cement.

The monkeys were seated in a sound-proof room, in a purpose-built 'primate chair' - an apparatus that restricts body movement. During each experimental session, the restrained monkey was exposed to a stream of pictures. His task was to hold his stare until he saw a fish. All of the experimental brain and eye recordings were computer-controlled, as was the delivery of a juice reward. An incorrect stare or no response on the part of the monkeys resulted in no reward being given. In all, the monkeys underwent 67 experimental sessions. What happened to them after the sessions was unrecorded.

Everling S, Tinsley CJ, Gaffan D, Duncan J. European Journal of Neuroscience 2006; 23:2197-2214. 'Selective representation of task-relevant objects and locations in the monkey prefrontal cortex.'

Edinburgh: Monkeys killed to demonstrate soy formula milk safe

A team of scientists at the University of Edinburgh investigated the effects on male sexual development of feeding infants with soy formula milk (SFM).

Different sets of infant marmoset twins were housed with their fathers and in sight of their mothers but separated from them by a wire mesh divider to prevent normal breast feeding. One group of twins was fed standard cow's milk-based formula while the other twins received SFM for a period of 30-40 days. Thereafter, the infant marmosets remained in their family groups until 18 months to two years of age, during which time each male was caged individually with an adult female. The male and female pairs were allowed to remain together (with any resulting offspring) until they reached 120-138 weeks of age when they were killed by lethal injection for laboratory study of their organs.

The SFM was declared to be harmless in monkeys. Many human infants are brought up on soy formula milk. In their conclusion, the researchers suggest that a simple blood test in humans is all that would be needed to find out the real answer to any doubts about the effect of SFM on humans.

Tan KAL, Walker M, Morris K, Greig I, Mason JI, Sharpe RM. Human Reproduction 2006; 21(4): 896-904. 'Infant feeding with soy formula milk: effects on puberty progression, reproductive function and testicular cell numbers in marmoset monkeys in adulthood.'

Funded by the Medical Research Council

University College London and University of Rochester, New York: Brain damaged monkeys rewarded with juice

In a collaborative study between a UK and a US scientist conducted at the University of Rochester (New York), two adult macaque monkeys were studied for their response to 367 different monkey calls. Both animals had previously undergone surgery during which electrodes were implanted into their brains. One of the animals was also fitted with an eye coil - an instrument used for recording eye movement, which is surgically implanted behind the conjunctiva (the delicate membrane that covers the front of the eyeball and lines the inside of the eyelids).

The monkeys were trained, using juice as a reward, to focus their attention on a central point, while listening to various sounds - including monkey calls - from loudspeakers. The researchers recorded the activity of brain cells associated with hearing.

Averbeck BB, Romanski LM. The Journal of Neuroscience 2006; 26(43):11023-11033. 'Probabilistic encoding of vocalizations in macaque ventral lateral prefrontal cortex.'

Funded by the National Institute on Deafness and Schmitt Foundation

University College London: 1983 monkey eye experiments repeated in 2005

Researchers at the Wellcome Laboratory of Neurobiology at the University College, London, experimented on monkeys to identify exactly which brain cells recognise colour shades. Six male macaques were used. The tests were conducted on four anaesthetised, and two conscious animals.

Two monkeys were trained to sit in a 'primate chair' - an apparatus that severely restricts body movement. Under anaesthesia, a recording device was implanted into their skulls, using stainless steel screws and dental cement. After regaining consciousness, they were immobilised in the chair and trained to stare at a point on a screen in front of them, whose background changed colour.

Similar experiments were conducted in the four anaesthetised monkeys, whose eyes could still register and transmit light waves. All six animals were killed and their brains examined. The authors admitted that equivalent knowledge of cell function was obtained during monkey experiments conducted in 1983.

Kusunoki M, Moutoussis K, Zeki S. J Neurophysiol 2006; 95:3047-3059. 'Effect of background colours on the tuning of colour-sensitive cells in monkey area V4.'

Funded by the Wellcome Trust

Oxford: Researchers debilitate 16-year old monkey

A team of Oxford University researchers experimented on a 16-year old macaque as part of an ongoing study of movement disorders associated with Parkinson's disease.

The ageing monkey had surgery to implant a deep brain electrode. It was connected to a pacemaker, which could be turned on and off by remote control. In subsequent experiments, the animal was incapacitated by the administration of MPTP - a chemical that damages the brain and severely impairs control of body movements. The researchers then experimented with a combination of standard drug treatment (L-DOPA) with and without activating the pacemaker.

It was found that the two treatments for Parkinson's (L-DOPA and electrical stimulation via the deep brain electrode) together gave the best overall result. A reading of equivalent studies in human patients suggests that this information has been known since at least 1999. The number of previous experiments that this 16-year old monkey had undergone and what happened to him following this debilitating study remains undeclared.

Jenkinson N, Nandi D, Oram R, Stein J, Aziz T. Neuroreport 2006; (17) 6: 639-641. 'Pedunculopontine nucleus electric stimulation alleviates akinesia independently of dopaminergic mechanisms.'

Funded by the Medical Research Council, the Templeton Foundation and the Charles Wolfson Charitable Foundation

Hull, Bristol, Nottingham and Newcastle: Nine monkeys killed in repetitive vision experiments

In a collaborative study, scientists from the universities of Hull, Bristol, Nottingham and Newcastle conducted vision experiments on nine marmoset monkeys. The animals were anaesthetised and also given a paralysing drug. The use of such a substance is of particular concern as may leave the monkeys unable to express the pain they feel.

The brains of the animals were surgically implanted with electrodes to record the activity of brain cells, while their eyes were fitted with contact lenses and subjected to varying light frequencies.

At the end of the experiment, all nine marmosets were killed by lethal injection. Their brains were removed for laboratory study.

In their conclusion, the authors noted that their results closely matched those of animal studies carried out 13 years ago. They also acknowledged that recent, non-invasive imaging studies in humans had already contributed important information to this field of study.

Barraclough N, Tinsley C, Webb B, Vincent C, Derrington A. Visual Neuroscience 2006; 23:815-824. 'Processing of first-order motion in marmoset visual cortex is influenced by second-order motion.'

Funded by the Wellcome Trust and the Biotechnology and Biological Sciences Research Council (BBSRC)

Oxford: Monkeys brain-damaged to make them indecisive

A team of scientists at Oxford University investigated decision-making behaviour in a group of nine adult macaque monkeys. Three of the monkeys underwent surgery during which deliberate damage was inflicted on an area in the brain thought to be important in decision-making.

All nine macaques were coerced into undertaking various reward-guided tasks. They were trained to manipulate a joystick for 150 trials per day, repeated for five consecutive days. The animals were required to get a correct result 25 times in succession, after which the frustration level was increased, as the experimenters demanded a different 'correct' answer.

Based on a comparison between normal, and brain-damaged monkeys, the research team concluded that the damaged brain area is 'essential for learning the value of actions'.

Kennerley SW, Walton ME, Behrens TEJ, Buckley MJ, Rushworth MFS. Nature Neuroscience 2006; 9:940-947. 'Optimal decision making and the anterior cingulate cortex.'

Funded by the Medical Research Council, the Clarendon Foundation, the Wellcome Trust and the Royal Society.

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