1. ROLE OF THE MEDIAL AMYGDALA IN FEAR POTENTIATED STARTLE AND SUCCESSIVE-CUE ODOR DISCRIMINATION
Tracy Cheng, Catherine Elorette, Xiaotong Li, Nicholas Chiappini, Daniel Wei, Jane Wang, Dedeepya Konuthula, Christopher Marnell, Keerthana Krosuri, Sayantan Deb, Courtney Halgren, Susan Liao
Susan

2. Pavlovian Fear Conditioning
Associative Learning:
Pairs a pre-occurring event or substance with a response
Conditioned Stimulus (CS) + Unconditioned Stimulus (US) = Conditioned Fear Response (CR)
Olfactory Stimulus + Foot Shock = Startle
Dan

3. Acoustic Startle Neural Pathway
Chris

4. The Amygdaloid Complex
Fear Response Pathway
Sayantan
Blue=basolateral, red=medial, green=central

5. Purpose
To determine the role of the medial amygdala in olfactory learning through:
Fear conditioning
Odor discrimination testing
Courtney

6. Subjects
Xiaotong
Nineteen male Sprague-Dawley rats, 12 hr light cycle/ 12 hr dark cycle, Limited to 30min water per day but free access to food

7. Fear Potentiated Startle
Tracy

8. Hypothesis
Lesions to the medial amygdala will disrupt startle response
Catherine, Supported by Walker, Paschall & Davis (2005)

9. Startle Chamber
Nick

10. Startle Test Trial Type Duration ISI Odor? Shock? Sound Pulse?
Matching
40 Pulses
30 s No
Yes, 95 dB
Baseline
Yes, dB
Odor/Shock
6 Trials
4 min
Yes
Yes, .5 mA
Odor/Pulse
70 Pulses
30 s (P)
2 min(O)
Chris

11. Fear Potentiated Startle
Susan

12. Conclusion
No significant effect
Keerthana

13. Odor Discrimination
Tracy

14. Hypothesis
Despite the lesions, the rats would still be able to detect and discriminate between the n-heptane and cineole
Catherine, Supported by Cousens & Otto (1998)

15. Odor Discrimination Chamber
Nick

16. Procedure Trial type 1 Trial type 2
Nose poke = water
Trial type 2
Positive odor & entry = water s black-out
Negative odor & entry = 9.5 s black-out
Other results = 2.5 s black-out
Rats were given only 30 min water every day to make them thirsty
Tracy

17. Frequency of Response by Type
Jane

18. Latencies Before Responses
Jane

19. Conclusion
No significant effect
Keerthana

20. Discussion

21. Findings Fear conditioning No disruption of startle response
Fear conditioning
No disruption of startle response
Odor discrimination
No effect of lesions on odor discrimination ability
Latencies
Percent correct response
Sayantan

22. Inconsistencies Histology has not been performed Small number of rats
Incomplete control of NMDA diffusion
Small number of rats
Innate preference for an odor
Dedeepya

23. Our Team

24. Thank You! Dr. Cousens, Anna Toledano & Jill NJGSS Sponsors:
John and Laura Overdeck, Novartis, Bristol-Myers Squibb, Jewish Communal Fund, Vanguard Charitable Endowment Program, The Ena Zucchi Charitable Trust, Village Veterinary Hospital, Fannie Mae Foundation, and NJGSS Alumnae and Parents
And everyone else who helped make
this experience possible! 

25. YAY WATER!

27. Questions?