An Introduction to Selective Breeding Program With Rats By Waseem Hassan

1. An Introduction to Selective Breeding Program With RatsBy Waseem Hassan

2. Objective !!!!Write down a Review….Comprising 8-10 different breeding lines..Focusing on their behavioral profile.

3. Selective Breeding Program Bi-directional selective breeding of organisms has been successful in many different species and for a wide variety of anatomical, physiological and behavioral phenotypes.

4. Anatomical Reasons • Brain weight, • Tooth width, and • Abdominal bristle number

5. Physiological Reasons • Rate of electrical self-stimulation of the brain • Duration of alcohol-induced loss of righting reflex also known as ‘sleep time’ • Susceptibility to, and/or severity of, seizures

6. Behavioral Reasons • Avoidance learning • Maze learning • Emotionality • Latency to copulate • Voluntary consumption of alcohol • Locomotor activity

7. Objective of Selective Breeding In a broad sense the objective is…. To Separate lines carrying, the distinct characteristics of a particular disease or pathological disorder.

8. In this seminar…. • High and Low Anxiety behavior Rats (HAB/LAB) • Roman High and Low Avoidance Rats • Floripa High and Low Lines • The focus will be on their behavioral Profile.

9. Behavioral Profile ..

10. The Floripa Lines • Andre Ramos in 2003, • Quest for a better genetic model. • For the study of stress and anxiety. • New line of wistar rats. • The main objective !!!!!! • To develop, through selective breeding, two new rat lines differing in locomotion in the center of the open field.

12. Open Field. After four generations of selection, the differences between the Floripa H and L rat lines regarding locomotion in the center of an open field As expected (H) lines displaying a higher locomotion in the central area of the open field than rats of the (L) lines.

14. Elevated plus maze • In the elevated plus maze, After four generations The Rats of the H line spent • More time in the open arms than L-line rats. Similarly, Rats of the H line made • Higher number of entries into the open arms than L-Lines.

16. To Note……. Entries in closed arms for both lines was not significantly different in initial breeding generations but later appeared in fourth generation where H rats showed a greater number of entries than L rats.

18. Black and white box • In the black and white box • (H) rats spent more time in the white compartment than L rats after four generation. • Floripa (H) lines also showed higher locomotion in Tha Floripa (L) lines. • High (H) lines made more transitions than Low lines in fourth generation.

20. Ethanol uptake • 1)…Ethanol up take , • No difference between the lines, however female drunk more… • 2)…Ethanol Preference , • No Line difference, however females have more preference for ethanol.

21. 1)…Ethanol up take ,

22. 2)…Ethanol Preference ,

23. Conclusion from ethanol uptake … • Females have more , • 1….Tendency to drink alcohol , and • 2….Preference for ethanol.

24. G.S. Izı´dio, A. Ramos / Alcohol 41 (2007) 517e524 • Izidio et al., 2007 have found that floripa L • females consumed more ethanol than their • floripa male counterparts.

26. Forced swim test • (L) lines line spend more time immobile than floripa (H) ..i.e. 6th Generation

27. 7th Generation… FST

28. SUMMARYThe present study demonstrates theimportance of genetic factors in the modulation ofanxiety-related behaviors, as well as the efficacy of selective breeding experiments in the development of genetic models for the study of anxiety/emotionality.

30. HAB/LAB… • At the age of ten weeks, rats were tested once on the elevated plus-maze and the males and females displaying the most anxious and the least anxious behaviour were sib-mated to start a new generation of the.. • High anxiety-related behaviour (HAB) and, • Low anxiety-related behaviour (LAB) lines, respectively.

31. Elevated Plus Maze….

34. Black White Box…

37. Social Interaction

40. Home cage behavior..

42. Ethanol Intake…

43. Daily ethanol intake (upper panel) and preference (lower panel) of female HAB and LAB rats

44. Endocrine function..

45. Endocrine function • Landgraf et al., in 2002 reported that HAB and LAB rats do not differ in their anxiety like behavior but also in their stress vulnerability and secreted more adrenocorticotropin (ACTH) and corticosterone indicative of hypo-thalamo-pituatary-adrenocortical (HPA) axis. However social defeat data of Frank et al., 2006 reported an interesting observation, he found that heightened trait anxiety can make rats more prone to stress and he measured higher levels of ACTH and Corticsterone in LAB as compared to HAB suggesting the possibility of stimulus dependent dissociation between behavioral and neuroendocrine stress responses. Salomé et al., 2004 al., also reported, that HPA-axis reactivity is more pronounced in HAB than LAB rats when exposed to mild stressors, including an open arm of the EPM or an open field.

46. Forced Swim Test…

48. Conclusion.. • The overall performance in these various behavioural tests suggests that selective breeding has resulted in rat lines not only differing markedly in their innate anxiety-related behaviour in the plus-maze, but also in other stress-related behavioural performances, suggesting a close link between the emotional evaluation of a novel and stressful situation and an individual’s coping strategy

49. Roman High vs Roman low active avoidance strains • Bignami et al., in 1965 started a series of experiments where rats from normal wistar population were tested for high and low rates of active avoidance conditioning in a shuttle box. After five generations, the two selected lines [Roman High Avoidance (RHA) and Roman Low Avoidance (RLA)] differed markedly (at least threefold differences) in the number of avoidances during the trials and this effect gender independent.

50. Defecation • When exposed to a novel environment (or various other stressors) RLA/Verh rats show more pronounced emotional responses such as more defecation. Taken a step ahead in this work when RLA/Verh were tested in six different test situations which involved either novelty or an approach/avoidance conflict Ferré et al. observed higher defecation for RLA/Verh strains. • However N. Castanon observed no difference in defecation scores in both lines, an interesting observation. • Ferré, P., et al. 1995. Physiol. & Behav.58: 1209–1213. • N. Castanon et al, Physiol. Behav.51 (1992), pp. 1235–1241.