| Program#/Poster#: |
479.21/FF122 |
| Title: |
Is the temporal structure of fear
conditioning processed in the amygdala? |
| Location: |
South Hall A |
| Presentation Time: |
Monday, Oct 19, 2009, 1:00 PM - 2:00
PM |
| Authors: |
*L. DIAZ-MATAIX1, J. E. LEDOUX1,
V. DOYERE2;
1New York Univ., New York, NY; 2NAMC, CNRS-UMR8620, Univ. Paris-Sud, Orsay,
France |
| Abstract: |
In Pavlovian conditioning, a conditioned
stimulus (CS) is paired with an unconditioned stimulus (US), so that the
CS comes to elicit conditioned responses. What is learned is not only that
the CS predicts the arrival of the US, but also when the US is expected
to arrive. In fear conditioning with long CS-US intervals, temporal patterned
behavior can be observed in rats after as few as one CS-US pairings (Davis
et al., 2001). In the present experiments, we asked whether the amygdala
processes the CS-US interval. In a first approach, we used a reconsolidation
paradigm in rats to test whether a change in the CS-US interval is detected
and triggers the updating of fear memory in the amygdala. Rats with bilateral
cannulae in the lateral amygdala were submitted to a strong training of
auditory fear conditioning. The next day, rats were submitted to a single
CS-US trial and immediately infused in the amygdala with anisomycin or vehicle.
The data of the long-term memory test indicate that a protein synthesis
dependent reconsolidation was triggered in the amygdala only when the CS-US
interval was different from the initial training. The results suggest that
a change in the expected time of the US arrival (US-ETA) triggers an updating
of the fear memory in the amygdala through a reconsolidation process. Further
experiments using electrophysiological recordings are currently performed
to analyse whether activity in the amygdala changes with the temporal structure
of the CS-US association, providing a potential basis for the encoding of
the US-ETA in the amygdala, and therefore a possible detection mechanism
for violation in the expectancy structure. |
| Support: |
R37 MH038774 |
|
P50 MH058911 |
|
R01 MH046516 |
|
CNRS-UPS-NYU EmoTime |
|
ANR-Memotime |