Sheridan GK, Dev KK. Targeting S1P receptors in experimental autoimmune encephalomyelitis in mice improves early deficits in locomotor activity and increases ultrasonic vocalisations. Sci Rep. 2014;4:5051. doi: 10.1038/srep05051.
Fingolimod (FTY720) is an oral therapy for relapsing remitting multiple sclerosis (MS) and targets sphingosine 1-phosphate receptors (S1PRs). FTY720 also rescues animals from experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The protective effects of FTY720 in EAE are primarily scored manually by examining weight loss and limb paralysis that begins around 10-12 days after immunisation. To our knowledge, pre-clinical effects of FTY720 on animal behaviour early in EAE have not been explored. Here, we developed an automated behaviour monitoring system to examine the early effects of FTY720 on subtle pre-symptomatic behaviour of mice induced with EAE. Our automated home-cage monitoring system (AHC-MS) enabled non-contact detection of movement and ultrasonic vocalisations (USVs) of mice induced with EAE, thus allowing detection of subtle changes in mouse behaviour before paralysis occurs. Mice receiving FTY720 emit longer USVs and display higher levels of motor activity than vehicle-treated EAE mice before clinical signs become apparent. Importantly, this study promotes the 3Rs ethics (replacement, reduction and refinement) in the EAE animal model and may also improve pre-screening of potentially novel MS therapies. In addition, this is the first report showing the early effects of FTY720 in EAE which underscores its protective effects.
The use of EAE is increasingly coming into the spotlight and is considered a substantial (compared to mild and moderate) procedure.
There is an ethical case to be made that you may not really need to allow animals to become paralysed, as a read out for experiments. For example studies on immune function using knockouts where you use paralysis as a readout for gene activity. You could simply do your test tube experiments and say record time to onset of pre-clinical weight loss, development of the first sign, etc….rather than letting paralysis occur. In this current study you could use vocalisations. However, do this and you run the risk of the referee pool from regions who are not so bothered about the 3Rs (not reading riting and rithmatic…but refinement, reduction and replacement) of animal use, who may bin your work.
However, just because in the past it was done, does not mean that it should be done. The 3Rs is now the corner stone of Animal experimentation in Europe. Times are changing.
It is becoming increasingly difficult to do such experiments in the UK.
In this study they designed a monitor to see what the mices were doing and in the first few days after induction with an adjuvant (stimulates the immune system) and whooping cough toxin, there was perhaps a sickness behaviour where they did not move as much and they were off their water. The toxin makes the number of white blood cells grow ten times to make them get EAE, we don’t use it. This no doubt is associated with immune growth factors which may you under the weather.
They used a drug FTY720 which is the ingredient drug in Gilenya/fingolimod to stop EAE and they found that these animals gave longer squeaks. We can’t hear it because it is ultrasonic.
The mice destined to get EAE did not squeak as much..
ProfG has had loads of whacky ideas about how to monitor movement of mices, but this system was all automatic and so unbiased and provides constant monitoring. The camera and Bat sound detector went onto a standard cage, which is what you want. There are systems that can monitor movement that can be implanted like a microchip for dogs and cats that can detect movement and temperature 24/7 (when a mouse gets EAE it moves around less and gets colder) but the system only worked for one mouse per cage and required a special cage and was very expensive, the manufacturers at the time were not interested for developing a system that would track multiple animals in a cage as mice are social animals and prefer to live in groups. This system also appears to measure collective responses, at present (at least in sound), where you would want individual readings as (a) we currently randomise within cages, rather than having all animals in one treatment in CageA and the other Cage B (b) Not all animals develop disease at the same rate.
The authors “do not see this system as a complete replacement to the current clinical scoring methods (which can check on individual animals), but rather an additional tool that can be used alongside gold standard routines to assess beneficial drug responses in EAE”.
We have shown that the gold standard clinical scoring routines are less responsive to looking at recovery and have shown that animals move less as disease progresses. The merit may be a way to look at progressive deterioration over time and because of its constant monitoring small changes in loss of movement may be amplified, meaning experiments don’t have to be as long…saving money on (mouse) hotel fees and less time in procedure for the beasties.
This is the type of approach that CRACK-IT aims to investigate. This is a NC3Rs programme aimed at developing practical approaches to address important issues to Industry, that have 3Rs potential.
Wonder how much the system costs?