Program#/Poster#: |
603.01/EEE4 |
Title: |
The transition to amygdala-independent
defensive behavior: Contributions of time and training in a signaled active
avoidance task |
Location: |
Hall F-J |
Presentation Time: |
Tuesday, Oct 16, 2012,
8:00 AM - 9:00 AM |
Authors: |
J. E. KLEIN1,
J. M. MOSCARELLO1, R. M. SEARS1, J. E. LEDOUX1,2,
*C. K. CAIN2,1;
1Ctr. for Neural Sci., New York Univ., New York, NY; 2Emotional
Brain Inst., Nathan Kline Inst. For Psychiatric Res., Orangeburg, NY |
Abstract: |
Instrumental active avoidance
(AA) depends on Pavlovian defense (fear) conditioning. The Lateral Amygdala
(LA) is crucial for the acquisition, storage and expression of aversive
CS-US associations in defense conditioning. Acquisition and initial performance
of AA also depend on LA (Choi et al 2010, Lazaro-Munoz et al 2010). As with
discriminative avoidance conditioning in rabbits (Poremba & Gabriel
1999), with overtraining the contribution of amygdala regions to AA performance
dissipates. We sought to define the conditions leading to amygdala-independent
AA. Rats were trained on a signaled AA (Sig-AA) task and then received lesions
of LA after different degrees of training, ranging from asymptotic levels
to overtraining (5, 10, 15 or 20 daily sessions). LA lesions produced severe
deficits in Sig-AA performance when placed after 5 or 10 training sessions,
moderate deficits after 15 sessions, and no deficit after 20 sessions. Interestingly,
although LA lesions impaired Sig-AA after session 5, retraining led to a
return of the Sig-AA responding. Since animals with pre-training LA lesions
never acquire the avoidance response (AR), this result suggests that LA
processes may prepare extra-amygdala regions to mediate Sig-AA responding,
and this preparation can be accelerated by taking the LA offline. Ongoing
studies are evaluating the critical factor in producing amygdala-independent
Sig-AA: additional training or additional time (i.e. systems level consolidation).
Thus, our results suggest that after overtraining, dependence on LA is no
longer necessary, as the AR transitions to an automatic, habitual behavior
perhaps governed by stimulus-response (S-R) associations. It is likely that
as associative control over behavior transitions, memory storage location
follows appropriately from LA to areas implicated in habit, such as the
dorsolateral striatum. With the time of transition now established, downstream
targets can now be examined. |
Support: |
NIDA - R01 DA029053 |
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NSF - 0920153 |
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Neural - R01 MH38774 |
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