"JUVENILE" STRESS AS A RISK FACTOR FOR IMPAIRED COPING BEHAVIOR IN ADULTHOOD - A RAT MODEL

1. "JUVENILE" STRESS AS A RISK FACTOR FOR IMPAIRED COPING BEHAVIOR IN ADULTHOOD - A RAT MODEL Tsoory, M. M.1, Cohen, H.2 and Richter- Levin, G.1 1 Dpt. of Psychology, Faculty of Social Sciences and The Brain and Behavior Research Center, University of Haifa, Israel 2 Faculty of Medicine, Ben- Gurion University of the Negev, Israel

2. Adulthood Stress Juvenile Stress ? INTRODUCTION • Most early-stress rodent studies focuses on the peri-natal and pre-weaning periods (i.e. 3 to 14 days). • Marked differences exist between rodents and primates Limbic-HPA axis course of development. • We have focused on the JUVENILE age.

3. experiment 1 Juvenile stress effects on learning under stress in adulthood Juvenile Stress 27-29 days Adulthood 56 Days ? forced swim 27 day • exploration • avoidancelearning 28 day elevated platform 29 day foot shock

4. Juvenile stress reduces exploratorybehavior in a novel setting in adulthood number of exploratory shuttles in 10 min. ** JVS CONTROL

5. TWO WAY SHUTTLE AVOIDANCE LEARNING AVIODANCE ESCAPE NO-RESPONSE

6. CONTROL JUV Juvenile stress impairs two wayshuttle avoidance learning ** ** ** ** ** avoidance shuttles blocks of trials (x10)

7. Juvenile stress produces two patternsof impaired avoidance learning Maladaptive (MA) Learned Helplessness (LH) % of subjects

8. JUV- Learned Helplessness JUV- Maladaptive Control Juvenile stress produces two levelsof impaired avoidance learning ** ** ** avoidance shuttles ** ** ## ## ## ## ## blocks of trials (x10)

9. POST-WEANING PRE-PUBERTY 26-42 DAYS ? Adulthood 65 days ADOLESCENCESTRESS JUVENILE STRESS • exploration • avoidance learning forced swim 33 day 27 day elevated platform 34 day 28 day foot shock 35 day 29 day experiment 3 Juvenile vs. Adolescence stress effects on learning under stress in adulthood

10. Both Juvenile and Adolescence stress reduce exploratory behavior in a novel setting in adulthood 14 12 10 ** n.s. 8 number of exploratory shuttles in 10 min 6 n.s. 4 2 0 JUV28 ADL34 Naïve Control

11. JUV28 ADL34 Juvenile but not Adolescence stress produces learned helplessness- like behavior in adulthood Learned Helplessness- like behaviors Maladaptive behaviors 71 61 % of subjects 29 23 10 6 1-20 21- 40 41- 60 61- 80 81- 100 % of no response trials

12. Juvenile stress confers a greater impairment than Adolescence stress on avoidance learning in adulthood 71% 29% 45% 55% • AVOIDANCE LEARNING CATEGORIES • GOOD- LEARNERS • AV>50% + NO<40% • BAD- LEARNERS • AV<50% + NO<40% • “LEARNED- HELPLESSNESS” • AV<50% + NO>40% 12% 28% 60% ADL34 Control JUV28

13. CONCLUSIONS • Adverse juvenile experience compromises learning under stress in adulthood. • The effects varied between maladaptive and learned helplessness behaviors. • The results suggest that Juvenile stress may increase the susceptibility to develop mood disorders, whilst Adolescence stress may increase the likelihood to develop anxiety disorders.

14. INNA KOGAN SHLOMIT JACOBSON OMER HOROVITZ YAEL LIGHTMAN DADI TAL KEREN SHEMESH SHIR TURGEMAN ELINOR STOLER SHIRLEY AVNI ITAY BEN- NAFTALI SPECIAL THANKScolleagues and research assistants:

15. Thank You