Marble/Mice Assignment Flashcards
Describe the type and characteristics of this model and discuss (as seen during the animal model lecture)
Explanatory model: to understand complex problems (often used in psychiatry). High fidelity, Isomorphic, Construct validity (behavior affected by same genetic background). It’s a repetitive behavior naturally present in mice that can be used as a model and their frequency and intensity can vary after genetic modifications.
Are the mice anxious because of the marbles? Are the mice burying the marbles on purpose?
The mice did not seem anxious because of the marbles rather because of being alone in a new environment. This is backed up by the literature. (Normally the mice should be acclimated to the study setting). It seems that mainly the mice do not bury marbles specifically but in the process of digging and burrowing, marbles become covered by the bedding . Some students did observe that some rare mice seemed to be burying on purpose (many students also mentioned rather vigorous digging from the mice in the nestlet experiment also).
What are we measuring exactly (for the marble and nestlet parts)?
What was measured: for the marbles, the amount of marbles that ended up being buried over 30 min, for the nestlet the amount of material shredded, which represent an objective measure of a repetitive and compulsive-like behaviors in rodents.
What section of the brain controls this behavior?
The hippocampus
What else could we have measured/evaluated during this experiment?
Different beddings, thickness of the bedding. The amount of times a marble was buried/ unburied/(buried). How much time was spent near the sides of the cage versus the middle of the cage. The roaming and grooming behavior (length, frequency, particularities, etc.). We could also have measured the signs of stress/comfortableness.
Discuss what this particular model (this behavioral assesment in mice) could be used to study.
This type of model is used to study disorders highlighted by the repeated expression of meaningless behaviors (such as OCD and autism). It can be used to assess different strain of mice (to better understand the genetic component of the disease, also different pharmacological compounds.
What are some advantages of using this behavior as a model.
Advantages: this is a behavior that is naturally present. This evaluation is simple and easy to perform. Both tests are easily and accurately scored and each is sensitive to small changes in the expression of compulsive-like behaviors that result from genetic manipulations, disease, or head injury. Mice are easily kept, easily bred
What are some limitations of using this behavior as a model.
Disadvantage: few disadvantages, does not reflect exactly the diseases modeled (but this is not the point). Is somewhat time consuming.
Report and discuss the characteristics of the mouse strain used.
We used CD-1 5-6 weeks old female white albino mice. Their origin comes from a group of Swiss mice that were used to create this stock. -Behaviour: fairly docile and easy to handle Genes: outbred, coat colour genes: albino. They are an all purpose strain of mice. Can be used as a reference point for normal behavior
