| Authors: |
*V. CAMPESE1, R. GONZAGA1, J. E. LEDOUX1,2;
1Ctr. For Neural Sci., New York Univ., New York, NY; 2Emotional Brain Inst., Nathan Kline Inst. for Psychiatric Res., Orangeburg, NY |
| Abstract: |
The encoding of Pavlovian associations between conditioned stimuli (e.g., tone: CS) and aversive unconditioned stimuli (e.g., shock: US) occur in the lateral amygdala (LA). Once acquired, the CS elicits conditioned responding in the form of defensive behaviors (e.g., freezing), which have been shown to depend upon the central amygdala (CeA). The trained CS is also capable of modulating learned instrumental behaviors. Whether the influence an aversive CS exerts on behavior is facilitative or suppressive depends on the motivational nature of the reinforcer associated with the instrumental response. For example, when an aversive CS is presented while the subject is responding for food, the CS suppresses instrumental behavior (i.e., conditioned suppression or cSup). Alternatively, after subjects have been trained to shuttle to avoid shock, an increase in shuttling rate is observed when the same aversive CS is presented (i.e., conditioned facilitation or cFac; Campese et al., 2013). Despite the opposing behavioral influences the CS exerts on responding, both the cSup and cFac effects depend on CeA (Killcross et al, 1997; Campese et al, 2014). In the current project, we show that serial LA-CeA connections are required for cSup of licking for sucrose. LA and CeA lesions as well as disconnections of these structures eliminated cSup in these studies. We also present data from a task that measures both cSup and cFac within the same subjects using an identical response for both tasks (i.e., two-way shuttling). Preliminary findings show that CeA lesions eliminate both cSup and cFac. Future studies will determine how microcircuits in the CeA are responsible for the opposite behavioral effects produced by the aversive CS. |