There are two aspects (at least...) to consider- in mice, as stated, you will have easier access to trangenics, there are in general more antibodies an reagents available, which will research easier for you. However, as some people above mentioned, the rat is by far a more intelligent creature and I would personally trust results from rats regarding cognition and behavioural tasks more than those from mice. Also, development is going fast and increasing availability in rat transgenics is happening. I think with well planned experiments you will get more relevant results from rats.

I'm assuming that you have no access to transgenics (which would be the best option) and you will try to reproduce some of the symptoms of dementia in naturally aged animals. If this is the case, the first thing you have to consider is that dementia is a pathological state. Therefore you will have to previously demonstrate that old mice present similar deficits to those seen in other models of neurodegenerative disorders (i.e. cognitive impairment in triple transgenic mice). However, answering your question, simply for practical reasons I'd go for mice.

Good luck!

It really depends on the type dementia that you want to study. Mouse models are more widely used. There are specific mouse models of AD characteristics (amyloid or tau). It really depends on the question that you are trying to answer.

If you work in a laboratory with substantial financial resources is best to choose transgenic mice.

It was recently published that rat F344-AD recapitulate the neuropathology observed in man i.e tangles plaques and cell death. The rat is more expensive but closer to man.

I think the mice model is better than the rats model. For there are a lot of transgenic mice model for studying the cognitive dysfunction, while the dementia rats model are usually injury models.

Think also about the outcome measures you will be using - in general, rats are brighter, so arguably better for use in complex tests looking at behaviour (e.g. cognitive ability)... but as has been pointed out, they are more expensive and there are very few transgenic rat lines out there... good luck!

i want to say mouse model. However, it really depend on what you'd like to look at as what Niall Colgan said. If you are looking at some therapeutic approaches, a well-established and well-recognised transgenic mouse model should be a good choice. However, if you are studying the pathological changes, mouse model is not necessarily the better one. As you study animal behavioural tests, mice would give you more unexpected conditions than rats for some reasons unknown. Perhaps, you may not be able to have a convincing conclusion at the end.

There are two aspects (at least...) to consider- in mice, as stated, you will have easier access to trangenics, there are in general more antibodies an reagents available, which will research easier for you. However, as some people above mentioned, the rat is by far a more intelligent creature and I would personally trust results from rats regarding cognition and behavioural tasks more than those from mice. Also, development is going fast and increasing availability in rat transgenics is happening. I think with well planned experiments you will get more relevant results from rats.

I think it depends on the method. Actually, Morris Water Maze is more appropriate for rats. However, it is not that rigid. Many studies apply MWM into the cognitive investigation of mice.

I think it will be difficult to say mice or rat is better. The base will be your hypothetical stand point of view. In any way, if you want to deal on dementia, it will be better to use either of the two containing human gene. As I have seen many research articles, transgenic mouse models are prominently used animals.

you can choose any of the species...

congnitive domains are well developed in both the rat and mice.

I would say you have study the detail pathophysiology of the respective model/strain and choose accordingly

Having worked with both rats and mice, knockouts, behavior and electrophysiology have to state that the behavioral cognitive paradigms that are mouse appropriate are not that well developed and draw from rat adaptions. Fear conditioning is the only big factory-like paradigm that is even vaguely successful in mice. There are many other motot tasks, rotor wheels etc, but few giving detailed behavioral performance related to cognition, as is available for rats with the Morris Water-maze, fear conditioning, David Olton's radial-maze, The Mumby box (a Delayed no-Match to sample task drawn from primate work), spontaneous alternation, novelty exploration all well developed cognitive paradigms.

In contrast, transgenics, Knockouts, "knockdowns" are all more readily available in the mouse, although there are some sparse transgenic and knockout rats becoming available. So as indicated above is detailed analysis of cognition more important, than a sound and readily available mechanism to alter via transgenic or knockout?

I work with both Wistars and C57s (among other strains). In my experience as well as through conversations with other researchers, rats in general may be a better model. They seem to be more conscious and aware of their environment whereas mice can be more spastic and easily excited. If you plan to do more complex tasks (operant behaviors and such) rats will definitely be the way to go. If you want to see more temperament-based results, then there may not be as much of a difference other than cost--Wistars are fairly docile and sedentary, but C57s are not as high-strung as other mouse strains and behavioral changes in that strain are more noticeable.

The moment you have to do neuropathology you will be happy to have chosen rat, since most of the neuroanatomy has been done in rats.

While performing surguries, such as streotactic surgery to induce cognitive deficit or dementia you will feel better handling rats as compare to mice.

It depends on the complexity of the cognitive test, but in principle, rats always perform better than mice, anyway, if you choose rats, Long Evans strain is far more accurate for cognitive tests than albino ones (wistar or sprague-dawley).

simply, you can use either rat or mice. In my case, I would prefer Wistar rat than mice. Best luck

Thanks everyone for your response. Appreciate it.

Both, rats and mice are good for the dementia or cognitive deficits except in transgenic study. The basic thing is the parameters to be studied. For behavior activities both are good but for the biochemical assays the requirement of the tissues have more importance. The hippocampus and cortex are the targeted parts. The wt of hippocampus in mouse is drastically less than rat. For more hippocampus you have to pool, so more number of mice will be required. Also more work will be required to develop AD in mice i.e. double or triple numbers than rats. Surgery is also a time gaining procedure and to test the AD in MWM test is again time gaining. So in case of mice the time required to confirm the AD will be at least double than mice. So it is better to used rats than mice if more biochemical assays are required. As other scientists have reported that rats are more intelligent than mice, so again rats are better.

As most everyone has said, rats are generally smarter and much more behaviorally consistent, which can result in increased statistical power, thus requiring fewer animals to get good results. This can sometimes offset the (significantly) higher price of housing rats. However, whereas the word on the street is that mice do not perform well in the water maze, my lab has observed excellent learning curves in mice over dozens of experiments, so don't let that deter you from using them if other factors make them the better choice over rats.

I think that rats is better to used: handling, stereotaxis coordinates!

Thanks everyone for your input.

Rats are better suitable than mice because of ease handling and consistent behavioral assessment and will get more tissue than mice for biochemical and other techniques to be followed.

Personally i wont support the two, insects appear better while old monkeys will be the best. In this insects like c.elegans and drosophilia, you can even do behavioral study

We have found BALB/c mice to be a much better option to Sprague Dawley Rats which did not perform too well in our studies.

personally i think mice are better than rats in cognitive and behavioural research, in test like the open field test, mice give better results than rats, the size of mice also give them an edge. it has even make getting transgenic models of mice easy. better understanding will be provided by this paper Modeling Alzheimer’s disease : from past to future by Claudia Saraceno, Stefano Musardo, Elena Marcello, Silvia Pelucchi and Monica DiLuca n frontiers in pharmacology

In my opinion, old Sprague Dawley rats performed very well on Barnes maze, which is less stressful and requires less physical demand as compared with water maze.

Not stated how you would plan to promote/induce neurocognitive impairment/dementia to model AD. Are you stereotaxically injecting amyloid beta? Tau? Elevating cholesterol somehow? Not transgenic approach presumably, since that is almost exclusively mice, If just want to cause learning impairment, try high binge ethanol and the water maze, which has been published!

Both, rats and mice are good for the dementia or cognitive deficits but if you want to study brain regions study then rat will better to handle. If you want to study transgenic mouse model then mice is better by considering handling and cost effective.

Just to share some of my experience.

It doesn't matter. All depends on your design and objectives. However, one thing to remind you that you have to make sure the emotional factor will not affect the learning and memory process, particularly for mice. Some sudden and loud noise will affect the mouse emotion much for up to a few hours. That will also affect your behavioural result very much. for some tests, liked NOR, you have to pay much attention on that.

Sprague Dawley rats were bred for docility. Thus, they are easier to handle than mice and less "skittish" as mentioned above. Mice were inbred to study transplant rejection (histocompatability haplotypes). Turns out about 40% of the inbred lines were genetically blind, and thus not very good at spatial navigation tasks (to say nothing of inbreeding depression....there is a reason we don't let cousins marry). Hybrid mice are typically healthy and intelligent. The brain to body weight ratio of mice is about three times greater than rats. I used rats for 20 years and mice for 20 years. The mouse genetics is too powerful a tool. Plus, mice cost less, an unfortunate reality with today's budgets..

Thank you all for the inputs.

I recommend you this article [Abbott (2004). Laboratory animals: the Renaissance rat. Nature 428(6982):464-6.] and this comment [Radcliffe (2004). Multiskilled mouse rivals Renaissance rat. Nature 429(6987):15]. Personally, I think rats are preferable than mice for cognitive assessment (you need a lower number of animals to reach statistical significance; rats are easy to handle and less aggressive; etc.). Among different rat strains, outbred and pigmented (such as Long Evans) are the best [Harker KT et al. (2002). Place and matching-to-place spatial learning affected by rat inbreeding (Dark-Agouti, Fischer 344) and albinism (Wistar,

Sprague-Dawley) but not domestication (wild rat vs. Long-Evans, Fischer-Norway).

Behav. Brain. Res. 134(1-2):467-77].

Hi,

In previous study for osteoarthrtis were done by SD rats. But my question is that SD is better for OA or Wistar and why ?

Could you please explain in a details?