Marmosets in Brain Experiments at the Department of Physiology, Monash University
Researchers at the Physiology Department at Monash University, Clayton, are using monkeys in an attempt to understand the connections between different parts of the brain and responses of neurons to visual stimuli.
Although the researchers, in their own publications as recently as this year, acknowledge the differences between the marmoset brain and the human brain these experiments continue at great cost - both in monetary terms and to the detriment of human health.
A study of some of the publications by researchers at the Physiology Department at Monash University has revealed the following experiments carried out on monkeys over the last few years.
In a 2000 publication(1), 6 marmosets were subjected to lesions on the brain resulting in scotoma (blind spot). The lesions were made by way of a suction probe destroying part of the brain. The brain was exposed by way of a craniotomy and after the lesions were performed the skull was cemented back in place and muscle and skin sutured back. After 3 – 4 hours the monkeys recovered their normal posture and started to drink. Several weeks after these lesions were made the monkeys underwent electro recordings of the brain. After anaesthesia they were placed in a stereotaxic frame (see diagram) and muscular paralysis induced and maintained while electrode penetrations were made. At the end of the experiment they were killed. In this publication the researchers stated that for “three decades controversy about the boundaries of the visual area in monkeys has absorbed experimenters around the world”. Sadly many years later and after many animal experiments this ‘controversy’ still continues with no tangible benefit to humans but needless suffering by the animals.
Experiments of this kind have continued year in year out at the University’s Department of Physiology.
In an experiment published this year(2), 14 marmosets were held in a stereotaxic frame while visual stimuli were presented on a screen in front of the monkey’s eyes and observations made measuring the activity in the brain and cell responses. Full details of how these marmosets are prepared for the recordings are referred to in an earlier publication(3).
One of the most disturbing things about this experiment is that the experimenters discuss the comparisons between marmoset and macaque monkeys and note the differences between these species and the fact that that the brain of the marmoset is 12 times smaller than the macaque translating into different results. They conclude that the processing of visual motion is at best only ‘likely’ to translate to the organisation of the human brain. After 30 years of research, should we expect a little more solid result than ‘likely’?
How Marmosets are Prepared for Recording Neurons in the Brain
Under anaesthesia a tracheotomy is performed. The marmoset is placed on a mat and its small head is secured in a stereotaxic frame to hold the animal completely still. The cortex is exposed and an acrylic wall constructed around the craniotomy is secured with screws. Rods connect the skull to the stereotaxic frame and the marmoset is chemically paralysed and artificially ventilated
Results from these experiments are unreliable as they cannot be reliably extrapolated to humans. The research carried out is for the sake of consuming large amounts of federal funding that could have been better spent assisting people with vision problems (annual funding must be spent by universities otherwise they may be in danger of having subsequent years funding reduced). For example, the experiment published in 2007 was funded by a grant from the National Health & Medical Research Council (federal taxpayer funded); and equipment was purchased with funds from the philanthropic organisations the Clive and Vera Ramaciotti Foundation and the ANZ Charitable Trust.
Taxpayer’s funding still continues with this year one of the researchers being awarded another NHMRCE grant of $442,875 for related experiments into the visual cortex.
What you can do
If you are appalled at the waste of resources in these experiments please write to the following organisations and express your concern.
ANZ Charitable Services
Research Projects – Management Section
Clive and Vera Ramaciotti Foundation
Professor Iain Clarke
- Rosa, MG.P., Tweedale, R. Elston, G.N., (2000) ‘Visual Responses of Neurons in the Middle Temporal Area of New World Monkeys after Lesions of Striate Cortex’ Journal of Neuroscience, 20(14):5552-5563
- Lui, L.L., Bourne, J.A. Rosa, M.G.P., (2007) Spatial and temporal frequency selectivity of neurons in the middle temporal visual area of new world monkeys (Callithrix jacchus)’ European Journal of Neuroscience Vol. 25, pp. 19780-1972
- Bourke, J.A., Rosa, M.G.P., (2003) ‘Preparation for the in vivo recording of neuronal responses in the visual cortex of anaesthetised marmosets (Callithrix jacchus)’ Brain Res. Brain Res.Protocol., 11 168-177
- Scan of response letter from Monash University (1016KB PDF)
- Reply to Monash University from Dr Andre Menache (29KB PDF)