1. Biology and Physiology of Laboratory Rodents András Bersényi DVM, PhDresearch fellow Szent István Univ. Fac. of Veterinary Science Institute of Anim. Breeding, Nutrition and Lab Anim. Sci. bersenyi.andras@aotk.szie.hu

2. Experimental animals Lab animals

3. Basic Requirements for Animal Models • Accurate mimicry • Data extrapolation • Result reproduction • Readily available • Tractable • Convenient size and prolificacy • Long lifetime • Easy to maintain • Relatively inexpensive

4. Mouse (M. musculus) Taxonomy Class: Glires Order: Rodentia Suborder: Myomorpha Family: Muridae Genus& Species: Mus house mouse(M. musculus)

5. History Biology I. Large Surface Area(20 g: 36 cm2) Cold (thermoneutral zone: 29.6-30.5oC) Heat

6. Conclusion: housing (20-24oC!), drinking water, floor II. Fast Heart and Respiratory Frequency(100-200/min.; 300-800/min.)

7. III. Urinary System IV. Pheromones Lee-Boot-, Whitten-, Bruce-effect

8. Mice in Research • Gerontology: • Genetics: (pregnancy: 19-21 days vs rat: 21-23 days) • Oncology: • Virology: • Toxicology • Radiobiology:

9. Rat (R. norvegicus) Taxonomy Class: Glires Order: Rodentia Suborder: Myomorpha Family: Muridae Genus& Species: RattusNorwegian rat(R. norvegicus)

10. History Biology Heat loss: sweat glands, tail vessels, saliva on body

11. Rats in Research • Nutrition • Toxicology • Behaviour(stress) • Inherited Diseases: hypertension, diabetes insipidus, retinal degeneration, audiogenic seizures, hydrocephalus, microophtalmia, deafness, obesity, non-eruption of teeth

12. Syrian/Golden Hamsters (M. auratus) Chinese/striped back hamster (Cricetus griseus) Armenian/grey hamster (Cricetulus migratorius) European hamster (Cricetus cricetus) Taxonomy Suborder: Myomorpha Family: Cricetidae Genus & Species: Mesocricetus golden hamster (M. auratus)

13. History Allepo, Syria (1930) Biology • black spot/sebaceous gland (males!)

14. I. Prolificacy(6 litters/year, 4-10 pups/litter) II. Freedom from Spontaneous Diseases

15. III. Anatomy & Physiology • Hibernation (2-3 days sleep + 12 hrs wakefulness): • Cheek Pouch: • Dentition: • Respiratory Tract: IV. Rapid Development(pregnancy: 15-17 days)

16. Other Chinese hamster

17. Gerbil (M. unguiculatus) Taxonomy Suborder: Myomorpha Family: Cricetidae Genus & Species: Meriones Mongoliangerbil (M. unguiculatus)

18. History Biology • sebaceous glands (males!) • short erythrocyte lifespan • desert origin: (thermoneutral zone(0-35oC), water requirement, urine excretion) • free of spontaneous diseases

19. Gerbils in Research • neurological research: idiopathic epilepsy • cholesterol metabolism:obesity atherosclerosis

20. Guinea pig (C. porcellus) short-haired/English rough-haired/Abyssinian (Ethiopian), long-haired/Peruvian Suborder: Hystricomorpha Family: Caviidae Octodontidae Genus& Species: Caviaguinea pig (C. porcellus)

21. History Biology • 1 pair of nipples; fingers: 4/3 • Biorhythm: appr. 20 hours activity and appr. 10 min sleeping • Coprophagia - caecotrophy (rabbit; guinea pig; chinchilla; degu; hamster -real coprophagy: rat! (foal)

22. Normal Caecotroph Form hard, singular globules 5-10 globules, cluster Components Dry matter (%) 50-55 30-40 Crude protein (%) 15-16 25-30 Crude fibre (%) 30 15-18 Vitamin ‘B’ low high Chemical composition of the rabbit’s two types of faeces(Fekete and Bokori, 1984)

23. Faeces of guinea pigs - Normal: crescent-shaped & dark - Caecotroph: cucumber seed-shaped & bright • Kurloff’s cells (3-4%)

24. Guinea pigs in Research • Easy to immunize: TBC, diphtheria, leptospirosis, brucellosis • Otology research • Scurvy