Morris Water Maze - Science topic

Hello Samir Ranjan Panda Hania Elhoshy ,

I have the same issue. I conducted experiments for 5 days with 4 trials per day. During the trials, some of the mice only touched the platform and continued swimming, while others crossed over the platform. However, some of them climb up the platform much time later after their initial touch. Which time should I be considered?

Thanks!

I have seen Rtrack (https://www.biorxiv.org/content/10.1101/2020.02.27.967372v1.full) but have not tried it.

Dear Joshua,

Many things can go wrong. Unfortunately, the MWM protocol is oftentimes introduced in the experimental workflow without the adjustments that are absolutely required for the test to work in the particular scenario you want to apply it to. As is the case with biochemical assays, you should make sure the test you are going to apply is able to discriminate between the conditions you want to study - for large effects on spatial memory, you don't have to worry so much as even not very sensitive protocols will be able to discriminate between the animals, however, if you want to study relatively small effects you have to make sure you design a protocol that is sensitive enough to detect the expected change. In other words, you have to design a protocol that is not too challenging, but also not too easy for your animals in your particular scenario. As with most assays (behavioral, biochemical, etc.) you should work on the go and adapt the method to your needs otherwise, it makes no sense to apply it (this is also why sample size calculations often fail in the context of basic sciences).

If you see that the animals in the control group are having a hard time learning what you are trying to teach them (e.g. to find a platform as soon as possible to get out of the pool) there are several possibilities:

1) Your controls may be stupid. You can test this by combining different cognitive assays (even for different types of memory as they sometimes have a tendency to cluster together if there is a case of severe cognitive decline). If they underperform in other tasks as well something may have caused unexpected cognitive deterioration (e.g. I have seen cases of infestation with parasites (e.g. S.obvelata that do not cause obvious symptoms but have a relatively pronounced effect on cognitive performance of otherwise relatively normal animals). The solution is to take care of whatever may be causing your controls to not be able to learn what you are trying to teach them - as the experiment makes no sense without the controls.

2) The protocol you are using may be too demanding in a given time frame. It helps me to try to think about it in a way that I am in the position of the animal myself. If somebody placed you in the water in an environment that makes it hard for you to see, and wants you to find a hidden platform without telling you how many "training sessions" do you think you would require to learn that you are supposed to find the platform to be saved from the pool? With this in mind, if you consider your protocol too challenging there are many things you can (and should) do.

Are your animals too stressed or not stressed enough by the environment? If they are too stressed they may fail to learn (e.g. if you throw them in the pool instead of placing them gently in the water). If they are not stressed enough they may not want to find the platform (e.g. the water is warm and they would rather swim than be taken out.

When you look at animals placed in the MWM for the first time you can clearly see that they first look for the exit from the pool (i.e. explore the environment). Some animals may find the platform, but still decide to look for other ways out. Different protocols affect the exploration strategy in different ways. For example, if you decide to remove the animal from the pool on the first day as soon as it finds the platform you risk that your animal may decide to explore some more in the subsequent trials just to make sure there is no other way out of the pool. If you, on the other hand, decided not to take the animal out as soon as it finds the platform you are simply not teaching the animal that the platform is what you want them to find (i.e. it successfully passed the test). Whether you are going to sacrifice learning in the first trials to let them explore their environment depends on what you are trying to study. Also, make sure the animals spend enough time in the pool. People standardly use 60 seconds, but it should really depend on the size of your pool and other conditions, and even if you use a standard size the trial time should be determined by having in mind the particular animal you are testing (e.g. if your animals are hyper or hypolocomotor 60 seconds may either be causing you to get unreliable data). If the animal runs out of time are you absolutely certain you handle it in a way that tells it to find the platform next time? You should approach it as if you were trying to teach a dog to come/go somewhere. For example, if you just drag the animal by the tail towards the platform, leave it there for a few seconds and take it out rapidly the animal will learn much more slowly that reaching the platform was the actual cause of you rescuing it from the pool. Determination of the optimal platform time is tricky as you also don't want to leave the animal on the platform for too long otherwise it won't associate the process of reaching the platform with the act of being rescued from the pool.

There should be some objects/signs around the pool to enable animals to learn where the platform is with respect to the spatial cues. If spatial cues are not present around the pool the test can be too challenging. If the spatial cues are present, but not constant in time this can confuse the animals and cause them to learn slower. For example – can animals see you during the test? If yes are you sure they are not trying to follow you instead of trying to find the platform? Alternatively, if you usually stand near the pool are you sure the animals are not using you as a spatial cue and therefore memorizing the location of the platform relative to the place near the pool where you are usually standing? If you are happy with all the conditions mentioned above are you making sure the animals have enough trials and that no other things are interfering with learning? Sometimes the protocol you design is simply too challenging to be taught in several trials. Luckily there is a simple solution to this problem – just increase the number of trials or days, but make sure your training is not too stressful or demanding as this will introduce a new source of bias. Also, make sure you are not doing other tests in parallel, other researchers are not interfering etc. As this can also obviously affect the rate at which they learn. These are some things that come to mind at the moment, but there are many more. I suggest that you try to think about the MWM protocol as if you were designing it to test yourself. All biases you can think of probably in some format also apply to your animals. I personally think that the best approach is to start with small and easy stuff as this is also how most people learn faster. For example, you can introduce trials at the beginning in which you let the animals explore the entire pool. You can also begin by placing the animal on the platform in the habituation trial to facilitate learning the position of the platform. After that, you can proceed with a normal trial, but you can position a platform in the pool in a way that the animal can see it. After that, you may decide to submerge it and try to teach the animals that the platform is still here, but that it is now underwater (you can teach them by showing them the way or placing them briefly on the platform). You can simplify your trial by reducing the number of positions from which the trial starts, however, you have to be extra careful not to introduce bias at this point, as the purpose of changing the starting position is usually to make sure the animal is really only relying on the spatial cues, and not using some other strategy to find the platform. To conclude, there are many ways you can approach modifying your MWM (and any other protocol) to make sure that it fits your experimental needs. Some people advocate for only using a single protocol as „this will eliminate possible sources of error“. This is very unscientific and simply very wrong as one solution cannot be applied to different problems with the same levels of success. I suggest you follow guidelines on MWM protocols, but modify them to fit your experimental needs – and importantly test the stuff you decide to modify to make sure you are eliminating and not introducing additional bias. If you do it mindfully and correctly you can expect to distinguish even relatively small effects using protocols that last no more than 1-3 days. Remember - this is glorified „animal training “, whoever this of it as a scientific tool to which common sense cannot be applied probably does not understand it well enough. All of this applies to rats and mice (males and females) and probably other animals as well. Nevertheless, some people suggest that you should be even more aware of potential sources of error with female animals as here you also have the effect of the menstrual cycle and its interaction with many different variables. To which extent the menstrual cycle affects different types of learning, learning strategies etc. is for another discussion, but as a general rule, one way to overcome the aforementioned problems in females is to align their menstrual cycles and test them as rapidly as possible (by applying the strategies mentioned above). There are some good and rapid protocols you can easily find in the literature (e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4303046/) Best Jan

You can color paint the rat with a veterinary marker - spray or stick. With a red or green neck, the tracker should not have a problem.

Shin Murakami Thank you for your valuable response. I will check them.

Latency in MWM refers to the time taken for a mouse to locate the escape platform. It is expected to reduce in a mouse with intact cognitive function and prolonged in condition of cognitive impairment.

@ Ghulam Md Ashraf - thank you for your response.

Nice Dear Michael Uebel

A couple of my mentors/colleagues are 'hard liners' that actually trained under Dr. Morris. They would say plot each trial on each day. Most of us, as you say, use block (or day) averages instead, and treat each animal's day average as a single measure, and then use a repeated measures ANOVA to statistically test.

My reasoning is threefold: 1- we're starting the animal from different quadrants on each trial- that means that for the two goal-adjacent quadrants, the direct path-to-goal is shorter than the direct-path-to-goal for the 'goal-cross-quadrant' starting position. Since we deliberately do not use the same quadrant drop order every training day, each trial's drop quadrant does not align across training days. 2- there is variability in the animal performance that is not associated with learning. 3- the amount of learning appears to be greater between days than it is between trials on the same day. So, block/day averaging does remove the within-day trial learning , but it also controls for non-learning-related biological variability as well as the quadrant drop effect (as long as all quadrant drop locations have equal representation on each training day).

The first trial on each day sometimes gets special attention. For instance, some papers only report the first trial of each day, while others report the day average but exclude the first trial from that average. The rationale behind treating the first trial as 'special' is that some animals (in my experience, this is more often the case with mice than rats) are more distressed during the first trial. You can see this by investigating the path traces for thigmotaxis (interpreted here as circling around the edge of the pool).

You may also see some researchers drop their last trial per day, reasoning that the animals are becoming exhausted- if you are consistently seeing longer latency/ path length on your last trial, you may consider modifying your design- either removing the 4th trial from analysis or increasing the inter-trial interval for future experiments. Water temperature (we keep ours at 26 degrees C) can also be an issue, with colder water fatiguing the animals. Again, this happens more easily with mice than rats.

Now, all of these approaches are appropriate in certain conditions, and obviously are 'allowed' because they have been published- a researcher just has to state what they did and their reasoning for it in the Methods section, and then some reviewers and an editor have to agree. But, this does create a temptation. Is the researcher cleaning up the data to make their results more clear, or is the researcher 'sculpting' the data to fit their hypothesis? You'll know you're doing it wrong if you are watching the output of your filtering strategies to find the graph that best supports your hypothesis.

Finding a difference in the first day between groups could mean there is a difference in mobility between control and experimental groups. The swim velocity during visual cue trials may help to determine this. If it is the case, consider using path length, or Gallagher's spatial learning index, instead of latency. This may be especially important for experimental conditions associated with Parkinson's or aging, where movement is a concern.

I see, thank you.

I'll do a pilot test and see if any part of my current protocol needs to be adjusted.

Yes, you can test the mice after ten days. We get excellent performances (i.e., precise spatial preference for the target position) in transfer (probe) trials performed 10 days or two weeks after training in the water maze. As Shira wrote, spatial memory for the target position is still very good 30 days after training. But it can last even longer. We tested remote memory in male and female mice and we could still detect a spatial preference for the target/platform position two months after the last learning session. Best, Fabio

From your question it's not really clear, do you aim to test such a hypothesis or to avoid unwanted effects of one task on another?

Fear conditioning in rats can be quite stressful, so the effects of stress modulators (corticosterone, noradrenaline) can definitely affect learning in the next task. But the effects will depend on shock intensity, the timing of each task etc.

If you could be more specific I'd love to provide more literature recommendations.

https://psycnet.apa.org/record/1998-10128-011

Halo Yuka, I think you should provide more information. All the different phases used in the MWM (acquisition, extinction, reversal¿?), order of such phases (ac + ext + rever?) number of sessions per phase (specially important in rever) as well as a short description (ext= take out the platform for a session and analyze de time into each quadrant of the pool -transfer phase/probe-? or ext= final behavior at late stages of the reversal learning?). Just for methods, I would recommend adding a visual stage at the end (decrease water levels around 2 cms under the platform and highlight the platform -something white or clear grey-). This discards visual alterations that could be a source of bias.

Hi Yuka,

There is no substitute for contextual fear conditioning if you want to investigate contextual fear conditioning... but if you want to focus on hippocampus-dependent memory (not necessarily *fear*), you can use the water maze for spatial tasks.

https://www.nature.com/articles/nprot.2006.116

All answers up to this point suggest not doing them at the same time and to space by 24 hours. While I fundamentally agree with both of these, there are times when these options aren't possible (e.g. treatments or training regimens).

The best practice if you want to run two tests in one day is to at least space them apart from one another by 30-90 minutes (depending on tasks, treatments, etc) and, most importantly, to counterbalance the order of the tests across all animals in each group. The interval allows for stress hormones to extinguish and the counterbalancing controls for order effects.

Hope this is helpful!

I agree with the above answer, but much too often I have seen water maze setups that are not optimized for the task. Make sure you are using spatial cues on each side of the room and not inside the maze itself, followed by lights that are also symmetrical.

Depening on what your actually readout is, 4-month-old 5xFAD TG mice do not show any behavioral phenotype compared to non-TG littermates at that age.

I could not even detect differences in older (7-month-old) mice. We usually dectect first behavioral differecnes in 10-12 month old females in the Morris water maze, but this is highly dependent of the setup and experimental procedure.

I would agree with the previously provided answers, however I would inquire about the following: 1st what is the interval between injection of LPS/Control and water maze? 2nd you stated that you have controls, did their injections schedule match? If both Controls and LPS injected mice both display equal amounts of thigmotaxis, it is possible that the injection itself could be the issue not so much the LPS. Mice inherently more stressed and water maze results vary greatly between laboratories. The injections may be the cause of stress can you do the following to reduce the stress of injections: 1) give LPS or Control injections after maze, if it is daily injections or 2) if you could give injections well before testing e.g. 24/48hrs before start of maze. As for exclusion, did you have an a piori parameter for exclusion? If not than no they should not be excluded. A easy test would be to have a single day of visible platform performance after hidden platform and probe testing. Once an a prior exclusion factor is established, such as failing the visible platform test, only those animals can be excluded. As in all animal behavioral testing, consistency is paramount to good data.

Dear Jovanka, in order to study spatial navigation in humans you can use virtual mazes.

Here you can find a virtual reality version of the Morris Water Maze, generally used for monkeys.

Several groups have utilized virtual Morris Water maze on humans. For example:

Here you can find a virtual Morris Water Maze for humans:

Another option is the virtual radial maze for humans, which you can find here:

Good luck!

I want to add the possibility of doing a visual water maze as a control. Here the animals have to find the platform that is clearly marked by a 'flag' that stick out above water. Ideally there should be no distal visual cues. The platform should be in a different position each trial. If both groups find the platform with similar latencies, their motivation, their ability to locate a platform using their vision and their motor skills are similar.

I suggest that you build our linear maze, no water and other complicated issues are needed. In the attached papers you have pictures and measures. very useful, I wrote my thesis 1985 on open-field ambulation after learning in mice. A mouse is 30g a rat 300g:

There´s a plugin for Image J, tha advantage is that Image J is free and there's macOS version

Here is a link where you can download "Image J" and also you can find the plugin

This is the plugin link

This is a video from youtube where you can see what's the plugin do

You can assess performance at different retention delays, using a delayed-matching-to-place paradigm that uses variable goal locations.

Please see, for example, da Silva, Bast, Morris, 2014, Learn Memory, for how performance at different retention delays can be compared:

If you only use one platform, I'm afraid the interpretation of your tests at different retention delays will be confounded by the different number of acquisition trials that rats will have received at the different retention intervals (if you include additional training trials with platform) or by extinction (if you simply run two probes at two different retention delays).

Got you!

Thank you for your support!

Hi Sarah,

You can refer to the following publication:

In the section "Test Protocols",, the authors state the following:

Hope it helps,

Cheers

Dear Polina, the best way to resolve the light reflection problems is to avoid direct illumination on the pool. Try to use, instead of the ceiling lights, a simple floor uplight lamp, keeping the illumination level low.

If percentages of time spent in the target quadrant are significantly higher than chance level (25%), then there is siginificant memory. On the other hand, if percentages are not different from chance level, animals have no significant memory of the platform location. In your case, the mice seem to have a spatial memory deficit. Alternatively, something could have gone wrong during the learning procedure.

Here https://www.nature.com/articles/srep14562

look at the Examples of swimming paths showing different types of behaviour.

If it's possible for you, you may consider Long Evans or Fischer 344 brown Norway hybrids. They're both better for behavioral analysis in general, and Fischer 344 BN are also available aged from NIA for studies relating to age-related disease (injections into aged animals may exacerbate pathology, which could be desirable in your setting).

We have developed a free software for animal tracking, we have tried it with fish, insects and rodents, you can download it at https://toxtrac.sourceforge.io

We would appreciate it if you try it send any feedbac or if you can share with us any video dataset.

We have developed a free software for animal tracking, we have tried it with fish, insects and rodents, you can download it at https://toxtrac.sourceforge.io

We would appreciate it if you try it and email me any feedback

It is advisable to keep an interval of 24h between the open-field and the MWM. If you can't avoid carrying out the two tests on the same day, then perform the open-field in a session before MWM. Never do the opposite, since the stress induced by the forced swimming in the MWM would affect the anxiety levels in the open-field.

I also suggest both the Atlantis rising platform and multiple platform locations.  I would use more than two locations, though, to reduce the risk of the mice picking up on the platform always being on the opposite side from last time.  Further, i would use different random sequences for each mouse, because if the mice have a tendency to search near the last platform location (which I would expect to happen initially), then they are likely to find a position 90 degrees to one side more quickly than 180 degrees away.  If each mouse has its own randomised sequence, that effect should average out..

Just to be clear, you would need multiple trials per day.  Across the first few days, you can expect the mice to learn some non-specific things, like not sticking to the walls, and how long they have to stay in one place to make the platform rise.  That will generate learning across days even with different platform locations, not only within days.  Once that has stabilised, you should be able to see effects of age in how much time is needed in the first trial of the day, and/or in how much they speed up from the first to the last trial of the day.

I don't know, though, how you would control for purely motoric decline.  Perhaps have a group for which you keep the platform in the same location throughout, so that you just measure swim speed?  Those mice are likely to spend less time in the water, though, so if initial speed is the same but they tire more easily, you wouldn't see that.  Unless you have two platforms, give the mice two seconds on a platform, then sink it and let them go for the other.  Then match for swimming time.  or something along those lines.  Then you have the difference that the swim speed test group gets a rest.  So alternatively, take more time to let the platform rise, perhaps yoked to a mouse in the memory test group.  That risks the mice just floating in place, though.

Disclaimer: I only ever trained rats in the water maze, and it was quite some time ago.

You can use Morris water maze with 5 days acquisiton with starting point changed for each trial and then retrieval is tested on sixth day. (In our study we generally used 4 day acquisition + 5th day retrieval).

After collection of data you can apply ANOVA followed by Tukeys or Bonferroni test.

You can use milk, but it will need to be shifted daily-- we run many rats, 50 or more in one set of water ,made opaque with milk. It is not the same as the forced swimming task--much larger volume of water and, after the first day, much less stress--there is an escape after all and the duration of each trial is much shorter. This water really only needs to be changed daily because the powdered milk will sour. You can purchase large bags of powdered milk in bulk and probably need to only add about 3-4 cups for a 5' pool about 2' deep. The paint is better and can last several days without needing to be changed. For paint, you will also need to stir it each day as it may settle to the bottom. Paint is also better if you have white rats-- use black tempera. I pick up paint at Michael's or A.C. Moore. You can probably also find it at most arts/crafts stores but I would recommend a bigger chain because it will be much less expensive. Walmart occassionally carries it too. Probably amazon as well. Whatever we use (now we have a tracker that doesn't require masking so we use plain water and it can last for at least a full week of testing)-- we always fish out all feces to prevent build up in the pool and it can be distracting to rats if you leave it floating on top of the water. Good luck!

dear Emma,

recent findings conccrning differences between man and rat has disclosed basic fundamental dissimilarities between the two, e g in terms of  astrocyte organisation and relations to neurons in humans but not in rat in addition to other differences that would seem to reduce the relevance of a rat model, sorry to say. Good luck anyway, Arne Brun

It´s a bright question.

In truth both case are acceptable, when you use i.c.v the ventricle will irrigate all brain parts (expected yes), when you put i.h only the hippocampus will be "treated", of course you need minor concentration of drug in i.h.

I give a suggestion. Compare the cases in your research...Probably your job become so interesting and your results too.

Re-bonjour Emmanuel,

Here another paper from Julie Deguil et al., Neuroprotective Effect of PACAP on Translational Control Alteration and Cognitive Decline in MPTP Parkinsonian Mice.

The results, indicates that a subchronic MPTP intoxication in mice decreased the dopaminergic neuron number, produced an activation of PKR way and an inhibition of mTOR way of TC especially in striatum and frontal cortex associated with a great activation of PKR in hippocampus. Moreover, in parallel to biochemical analysis, the mnesic disturbances induced by MPTP were characterized in C57Bl/6 mice, by testing their performance in three versions of the Morris Water Maze task. Behavioral results showed that the MPTP lesion altered mice learning of a spatial working memory, of a cued version and of a spatial reference memory task in the water maze...

Dear Wong, It depends if you are more interested to see an impact on memory (then it is better to do the training before) or learning itself (then it is better to do it after chronic stress), though this distinction is not very precise (acquisition/learning of MWM involves memory as well).

Two additional notes: if you do the training before stress the danger is that conrol rats will forget as well, the memory trace needs to be strong; if you do the training after stress the main problem might be motivation – the animals might not be willing to learn or can be stressed so much they might not care about learning. Then you should think about ensuring to know they learned and, e.g., compare immediate probe trial and 3-5 days later one. In general, fear conditioning would be better in such a setup, especially with training before the stress. Good luck, Robert

Hi Rafael,

I agree with Philip and Li-Ming, C57BL6 have been a very reliable behavioral background strain for behavior. Some mouse strains are either very poor or too good at learning a skill but the C57BL6 mice are in the middle, which means that whatever variable you introduce has the opportunity of either increasing or decreasing their ability to perform in a task.

Best of luck in your studies!

Dear Anantha,

From my experience, it is often difficult to exploit all behavioral data from animals successively evaluated in a battery of tasks. This is all the more true when, as you plan, rodents are going to be tested in a high number of paradigms pertaining to different domains (activity, anxiety/depression, learning and memory).

Therefore, I would first advise you, if possible, to review your initial study design so that you can separately investigate learning & memory (1. Y Maze 2. NOR 3. Water Maze) and other functions (1. Open Field 2. Marble Burying Test 3. Light/Dark Box) with distinct batches of animals.

If for some reason this is not a viable option, I would propose the following order for your behavioral testing: 1. Open Field (provided that you measure activity levels rather than anxiety) 2. Y Maze 3. NOR 4. Marble Burying Test 5. Water Maze. Although the two last assays certainly increase stress in mice, I consider that the Water Maze has a higher aversive component because the associated training period lasts longer. As for the Light/Dark Box, I would abandon the idea to include it.

Yes, here's one:-

Shiotsuki H1, Yoshimi K, Shimo Y, Funayama M, Takamatsu Y, Ikeda K, Takahashi R, Kitazawa S, Hattori N.

J Neurosci Methods. 2010 Jun 15;189(2):180-5. doi: 10.1016/j.jneumeth.2010.03.026. Epub 2010 Mar 30.

Hi,

Can't say much about research on that are but there are some amazing tools for building exploitable 3D environments. Here are the big ones (some free but with conditions):

1) Unity3D http://unity3d.com/ 

2) Unreal engine https://www.unrealengine.com/

3) Cry-engine http://cryengine.com/

4) Torque 3D http://www.garagegames.com/products/torque-3d

Also you may want to try the free and open-source 3D modelling software and game-engine blender: http://www.blender.org/

Of all of the above I've only used Blender and Unity 3D. Both can take quite some time to learn and develop with (thought Unity is easier from my point of view).

Just a last suggestion. Since maybe you just want a 3D exercise without many visual effects or complexity you could do the easier approach. Check the this link for a kind of FPS in less than 300 lines of code: http://www.playfuljs.com/a-first-person-engine-in-265-lines/

There are many more and you may want to try especially if you decide to use an engine library instead of a a full software solution for development. Examples are:

1) JmonkeyEngine http://jmonkeyengine.org/ (Java)

2) Panda3D https://www.panda3d.org/ (Python)

Some of these engines (such as Unity 3D) come already with an FPS example so you can use it to modify it for what you need. I think it's worth the time exploring a bit the documentation it exists before jumping to a single solution.

Thanks for all great suggestions! I would determine if they have retinal pathology. I will test their olfactory function and then perform  smell-based memory test. Also I am planning to try fear conditioning with using auditory cue.  

Yes both tests are very stressful for mouse but firstly train your mice - as all these procedures usually require some training exercise so that mouse knows what he needs to do to recover/survive/escape. It helps if you know your mice too...you might check out the International Mouse Phenotyping Resource of Standardised Screens for specific details of methods

If you plan to do these experiments on the same cohort of mice I think I would do the water maze first because it triggers survival instinct and they will  associate you with rescue &  will trust you more. Fear conditioning is best done in mice that live in small groups together so that they can reassure each other that all is OK now they have returned to their home cage. Solitary housed mice don't have the luxury of reassurance from another mouse so it will be more stressful for them ! Good luck

Hi Paul

Floating (or freezing) can have several reasons:

Hi Gaurav,

As your test compound half life is 12 hours and I don't think that you have to go wash period to check the changes in the behaviour. Your main aim is to check the effect of test compound on behaviour and/or memory and/or betaamyloid levels, I suggest you to test periodically like Day 1, 3, 7, 14, 21, 28, 42 60 day during treatment and day 1, 7, 14 and 30 day of withdrawal. So you can better correlate with varies parameters like drug levels, chronic treatment, betaamyloid levels and changes in behaviour (PKPD).

Try to get as much as information as this is a transgenic mouse model.

All the best.

Regards

Ramanatha 

I have some difficulties to understand your question. Do you ask what to use for inducing AD and then restore it with R-flurbiprofen or do you ask how to use Morris water maze? Whatever maze is chosen is good for this purpose.

The Morris water maze like other mazes can be used for different purposes. This apparatus is one of the most widely used tasks in behavioral neuroscience for studying the psychological processes and neural mechanisms of spatial learning and memory. Rats or mice are placed in a large circular pool of water and required to escape from water onto a hidden platform whose location can normally be identified only using spatial memory . There are no local cues indicating where the platform is located. Conceptually, the task derives from place cells that are neurons in the hippocampus which identify or represent points in space in an environment (O'Keefe, 1976).

Place navigation in the watermaze is often used as a general assay of cognitive function (Brandeis et al., 1989), for example for testing the impact of various disturbances of the nervous system (e.g. animal models of stroke (Nunn et al., 1994), aging (Gallagher and Rapp, 1997), neurodegenerative disease (Hsiao et al., 1996), or the potential impact of novel therapeutic drugs (D'Hooge and De Deyn, 2001). The task has also inspired computational neuroscientists and roboticists interested in navigation (Krichmar et al., 2005).

I suggest that you contact people at MRC Harwell, Oxford, UK - they are testing C57BL/6J and 6N strains, as well as knockouts and other mutants on those backgrounds, in the WM. Prof. Steve Brown can advise who would be able to help you.