Traumatic Brain Injury to rats by dropping a 450g weight onto their exposed brains

Vivisectors at Monash University have been attempting to study the long term consequence of Traumatic Brain Injury (TBI) in the cortex of laboratory rats to see what changes take place in neuronal processing.

The rat cortex receives input from the mystacial whiskers that allow navigation in confined spaces and detection of objects.

The Procedure

33 rats underwent surgery – 19 had TBI inflicted upon them using what the vivisectors called the “weight-drop impact acceleration method” and 14 had surgery without the TBI impact.

The weight drop impact acceleration method to cause Traumatic Brain Injury
This odious method of causing brain injury in rats involves, under anaesthesia, a metal disk (1 cm diameter and 3mm thick) being fixed to part of the skull with dental acrylic. Each animal is then disconnected from the ventilator and placed under a ‘trauma device’ whilst a 450g weight is dropped from 2metres through a vertical tube onto the metal disk in the brain.

After this injury was caused, the rats were then re-attached to the ventilator and breathing resumed after approximately 5 minutes after which they were then taken off the ventilator and the metal disk was removed.

The animals were then subjected to a number of behavioural tests including rotarod, beam walk, adhesive tape removal (taped to their paws) and whisker and forepaw tests for up to 10 weeks after surgery. The forepaw test relies on the animal’s ability to detect the presence of a surface using its whiskers alone.

Eight to ten weeks post-surgery the animals were tested in terminal experiments. They were anaesthetised and then had their skulls exposed. Their heads were held in a head bar as electrodes were inserted through the brain to take recordings of the whisker motions.

Graphic warning!
The following link shows footage of a rat undergoing a similar preparation to those used in this research – prior to the injury being inflicted. It is not the actual experiment described.
http://www.youtube.com/watch?v=N4wSl699OG0

The Results

The vivisectors claim that after traumatic brain injury animals “showed significant and persistent sensorimotor deficiencies in all areas”.

Relevance to Humans

According to Dr Andre Menache, BSc (zoology), BSc(Hons), BVSc, MRCVS, “The study by Alwis et al falls under the heading of basic research, which by definition, makes no claim to clinical application. Animal researchers conducting these basic studies typically make some reference to human conditions in order to justify the funding of such endeavours”.

Further, according to Menache, “the choice of the rat to study traumatic brain injury ignores species differences and evolutionary biology. The rat possesses a four layered lissencephalic cortex (humans possess a six layered gyrencephalic cortex) and are separated by 70 million years of evolution.     These facts have important consequences when trying to extrapolate results from animal studies to humans. As an example, more than 1000 drugs have demonstrated neuroprotection in animal models (mostly rats) of experimental stroke. However, none have shown neuroprotection in humans. This represents a success rate of zero.”

Cost - Benefit  Assessment

The Australian and New Zealand Council for the Care of Animals in Research and Teaching states that: “Using animals for scientific purposes is acceptable only when any harm done to the animals is very greatly outweighed by the benefits of their use”. The study is clearly an example of basic research which is defined as “experimental or theoretical work undertaken primarily to acquire new knowledge of the underlying foundations of phenomena and observable facts, without any particular application or use in view” (OECD definition).”

It is unclear as to whether the authors could forsee any application of this work.  The publication does not provide any evidence to show that the information obtained from the killing of these animals will lead to benefits for people with traumatic brain injury.

Studies of sensory processes and deficits in humans suffering TBI should instead be relied upon to provide information regarding cognitive processing and possible rehabilitation.

The NHMRC should fund experiments using new imaging techniques in humans rather than attempting to recreate brain injury in laboratory animals.

The experiment was funded by a substantial grant of $557,760  by the National Health and Medical Research Council (NHMRC) – i.e. Australian taxpayers funded this experiment. (NHMRC GRANT APP 1029311,A/Prof Ramesh Rajan; A/Prof Helena Parkington; A/Prof Cristina Morgantiā€Kossmann;  Monash University).

What you can do

Write to

Research Projects,
Management Section,
NHRMC,  GPO Box 142
Canberra ACT 2601
Email: nhmrc@nhmrc.gov.au

Australian Research Council
GPO Box 2702
Canberra 2601
Email: info@arc.gov.au

asking that they no longer fund unscientific animal-based experiments.

Write to the Animal Ethics Committee that approved this and similar experiments :  

Dr Alana Mitchell
(AMREP) Animal Ethics Committee Chair,
Alfred Medical Research & Education Precinct Animal Ethics Committee,
3rd Floor, East Block,
The Alfred Hospital,
Prahran Vic 3181
alana.mitchell@bakeridi.edu.au

and

Monash University Standing Committee on Ethics in Animal Experimentation
Monash Animal Ethics Office
Faculty of Medicine, Nursing and Health Sciences
Building 13C, Wellington Road, Clayton Campus
MONASH UNIVERSITY Vic 3800
animal.ethics@monash.edu

References

Alwis, DW, Yan, E.B., Morganti-Kossmann,M.C., Rajan, R (2012) Sensory cortex underpinnings of Traumatic Brain Injury deficits, PLOS One, 7:12 p 1-19

 

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