LeDoux Lab 2012 SfN Abstracts
 
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
NSF - 0920153
Neural - R01 MH38774