| Program#/Poster#: |
614.16/WW69 |
| Title: |
Active vs reactive responding to
a threatening situation produces differential c-fos activation in specific
amygdala subregions. |
| Location: |
Hall A-C |
| Presentation Time: |
Tuesday, Nov 15, 2011, 11:00 AM -12:00
PM |
| Authors: |
*R. C. MARTINEZ1,2,
N. GUPTA2, G. LÁZARO-MUÑOZ2, R. SEARS2,
L. POLI DE FIGUEIREDO3, J. E. LEDOUX2,4,
C. K. CAIN2,4;
1Sao Paulo, Brazil; 2Ctr. for Neurosci., New York
Univ., New York, NY; 3HCFMUSP, Sao Paulo, Brazil; 4Emotional
Brain Inst., Nathan S. Kline Inst. for Psychiatric Res., Orangeburg, NY
|
| Abstract: |
Performance of instrumental active
avoidance (AA) is constrained by Pavlovian defensive reactions such as freezing.
Both AA and freezing depend on the lateral amygdala (LA) for learning and
initial performance, however, these opposing behavioral responses to a threatening
situation appear to rely on different outputs of the LA. Conditioned freezing
critically depends on the central amygdala (CE) whereas AA depends on the
basal amygdala. Interestingly, rats that freeze excessively and perform
poorly in the AA task show rescued AA performance following CE lesions that
abolish conditioned freezing. In these experiments we attempt to identify
amygdala nuclei, and subregions within these nuclei, that contribute to
the competition between instrumental and Pavlovian responses with AA training.
Amygdala expression of the immediate-early gene c-fos was measured
shortly after a shock-free test of Sidman AA performance in rats. c-fos
was activated throughout the amygdala compared to box controls, however,
poor AA performers showed significantly less activation in most areas examined.
Interestingly, only three regions showed significant correlations between
behavioral performance and c-fos expression: the dorsal part of LA,
the lateral part of CE and the anterior part of the medial amygdala (ME).
In each of these areas, c-fos expression correlated positively with
AA responding and negatively with freezing. Thus, this unbiased approach
suggests that LA, CE and ME may play important roles in the competitive
selection of defensive actions vs reactions in threatening situations. |
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