Comp Med No. 4 2011

Question 1

What species is most commonly used as models for stroke?

A NHP

B rat

C mouse

D rabbit

Answer 1

C mouse

Question 2

True/False: Occlusion of the anterior cerebral artery is the most commonly used surgical approach to produce EVA

Answer 2

False: middle cerebral artery

Question 3

True/False: Stroke can be induced in rabbits by immunization

Answer 3

True: immunization with a HL60 promyelotic cell differentiation factor

Question 4

Name 3 methods of inducing stroke in animal models.

Answer 4

• embolism introduction (mouse, rat, rabbit)
• middle cerebral artery occlusion (rat)
• perforating artery occlusion (rat)
• endothelin 1 injection (rat)
• spontaneous stroke (rat, dog)
• bilateral carotid occlusion (mouse)
• 2 injection of sodium laurate into internal carotid artery (rat)
• genetic model of CADASIL syndrome (mice)
• immunization with a HL60 promyelotic cell differentiation factor (rabbits)

Question 5

What is the definition of Environmental Enrichment?

Answer 5

Environmental Enrichment has been defined as the use of housing conditions that offer enhanced sensory, motor, and cognitive stimulation of brain neuronal systems in comparison with standard caging.

Question 6

List some common features of EE paradigms.

Answer 6

• Social housing
• larger enclosures
• increased environmental complexities (e.g. toys, structures for climbing, foraging opportunities etc.)

Question 7

Define Stereotypy.

Answer 7

Stereotypy is repetitive, unvarying, purposeless behavior that can occur in people and animals.

Question 8

T/F: The same form of EE can reduce aggressive behavior in some strains of mice, while increasing aggression and physiologic indices of stress in other strains.

Answer 8

True

Question 9

With respect to the effect of environmental enrichment on research, list factors that should be considered when implementing an EE program.

Answer 9

• undefined effect on animals
• potential for increased variability in the data
• poor definition across laboratories and in publications
• potential for harm to the animal or the study
• relative costs and benefits associated with adequate, optimal, and preferred housing

Question 10

Name two types of stain that can be used to identify P. neurophilia infection of zebrafish

Answer 10

• Luna stain and Fungi-flor.
• Luna stains microsporidian spores red in histological section.
• Fungi Flore fluoresces in the presence of the chitinous wall spore.

Question 11

When testing for infection of zebrafish with P. neurophila, what are the most important tissues to examine?

Answer 11

Spinal cord and brain tissues

Question 12

What substance is recommended to clean tanks known to be infected with P. neurophilia spores?

Answer 12

A bleach bath of at least 100 ppm chlorine, pH7 for 10 minutes will kill 99% of spores.

Question 13

What is the scientific name of the zebrafish?

Answer 13

Danio rerio

Question 14

Pseudoloma neurophilia, a microsporidian parasite, is increasingly prevalent in zebrafish research facilities. How is this agent transmitted?

Answer 14

Transmission of this obligate intracellular parasite may come through ingestion of the mature infective spore or during spawning.

Question 15

What are some clinical signs of P. neurophilia infection of zebrafish?

Answer 15

Affected fish may have clinical signs including emaciation and spinal curvature, but normal fish can have heavy infections.

Question 16

Mdr1a-/- mice are used as a model of what condition?

Question 17

Ldlr -/- mice are used as models of what disease?

Answer 17

Atherosclerosis

Question 18

What are the basic features of an atherogenic diet?

Answer 18

High fat & high cholesterol

Question 19

What manipulation must be performed to induce atherosclerosis in Ldlr -/- mice?

Answer 19

They must be fed an atherogenic diet. Athersclerosis does not develop spontaneously on normal diet.

Question 20

Briefly describe the TUNEL assay and what it is used to measure/detect.

Answer 20

TUNEL assays (terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling) are used to detect DNA fragmentation with labeling of terminal ends of nucleic acids via the TdT repair enzyme. It can be used to identify cells in the last stage of apoptosis.

Question 21

True or False: Magnetic field therapy may be preferable to chemotherapy or radiation therapy in treatment of cancer due to sparing of healthy tissue

Answer 21

True

Question 22

For what disease does the STR/ort mouse strain serve as an animal model?

Answer 22

Spontaneous osteoarthritis - mice exhibit human-like cartilage lesions at approximately 12 to 20 wk. The etiology of the OA is not clear in this strain. The mice have demonstrated increased levels of matrix metalloproteases, inflammatory cytokines IL1α, IL1β, and IL6; and oxidative stress in areas of osteoarthritis lesions, similar to findings in human osteoarthritis

Question 23

What are the biomarkers RAGE, AGE, S100A4, and HMGB1 used to evaluate?

Answer 23

Low-grade inflammatory and oxidative stress

Question 24

Name two chemicals and their mechanism of action that are used to induce diabetes in animals.

Answer 24

• Alloxan - a glucose analogue
• Streptozotocin (STZ) - a glucosamine nitrosurea alkylating agent
• Both chemicals are preferentially toxic toward pancreatic β cells

Question 25

Explain why is STZ selective for pancreatic Beta cells?

Answer 25

The selectivity for β cells is associated with preferential accumulation of the chemical in β cells after entry through the GLUT2 glucose transporter receptor: chemical structural similarity with glucose allows STZ to bind to this receptor

Question 26

What is the genotype of nude mice?

Answer 26

Fox1nu/Fox1nu homozygotes

Question 27

With respect to behavioral testing of rodents, what is the BFP test?

Answer 27

Buried Food-Pellet test: It tasks the subjects with relying on the sense of smell to locate food. Food is hidden in a novel cage and the time that the mouse required to uncover the food and grab is recorded. The bedding is changed for each mouse with the food being buried in the same location.

Question 28

What is anosmia?

Answer 28

Anosmia is the lack of the sense of smell.

Question 29

What does a Morris water maze test?

Answer 29

Spatial memory

Question 30

What is the motivating factor in a Morris water maze?

Answer 30

Animals are placed in a liquid of sufficient depth to require swimming, and the motivation is to achieve a safe perch out of the liquid.

Question 31

Briefly describe how a Morris water maze test is conducted.

Answer 31

A MWM is conducted usually using a circular liquid chamber. A resting platform is secured in place just below the surface of the liquid, and an opaque liquid is used to obscure platform and prevent animals from finding it visually. Visual cues may be placed on the sides of the maze to act as reference points for the animal in future tests. An animal is placed within the liquid and allowed to swim until the resting platform is located. The experimental variable is the time required for the animal to locate the platform.

Question 32

RCS rats are an inbred strain of rats that is well-known for __________, and RCS stands for__________?

Answer 32

Retinal degeneration and Royal College of Surgeons

Question 33

The iridal defect seen in RCS rats with ectopic pupils is seen in what position?

Answer 33

Inferior, at the 6 o’clock position

Question 34

The mode of inheritance for ectopic pupils and ocular coloboma in the RCS rat strain is_____?

Answer 34

Autosomal recessive with incomplete penetrance

Question 35

What is ocular coloboma?

Answer 35

A congenital anomaly in which various structures of the eye (iris, retina, choroid, or optic nerve) are absent. Retinal detachments are common in patients with ocular coloboma, and the defect directly affects visual acuity if it involves the macula, fovea, or optic disc

Question 36

True/False: Microphthalmia may be an indicator of coloboma in laboratory animals.

Answer 36

True: Ocular coloboma has been reported to occur in some strains of colored mice, and the coloboma is readily detectable by the reduced size of the eyeball