General and Specific Aversive Modulation of Active Avoidance Require Central Amygdala

Abstract

Three studies provide evidence that the central nucleus of the amygdala, a structure with a well-established role in conditioned freezing, is also required for conditioned facilitation of instrumental avoidance in rats. First, the immediate early gene c-Fos was measured following the presentation of a previously shock-paired tone in subjects trained either on an unsignaled avoidance task or not (in addition to tone only presentations in naïve controls). Significantly elevated expression of c-Fos was found in both the avoidance trained and Pavlovian trained conditions relative to naïve controls (but with no difference between the two trained conditions). In a subsequent study, intracranial infusions of muscimol into the central amygdala significantly attenuated the facilitation of shock-avoidance by a shock-paired Pavlovian cue relative to pre-operative responding. The final study used a virogenetic approach to inhibit the central amygdala prior to testing. This treatment eliminated the transfer of motivational control over shock-avoidance by both a shock-paired Pavlovian stimulus, as well as a cue paired with a perceptually distinct aversive event (i.e., klaxon). These findings provide compelling support for a role of central amygdala in producing aversive Pavlovian-instrumental transfer.

Functional Magnetic Resonance Imaging Signatures of Pavlovian and Instrumental Valuation Systems during a Modified Orthogonalized Go/No-go Task

“…To the best of our knowledge while there are no previous imaging studies that have documented Pavlovian value signals in the vmPFC or dorsal ACC, recent research work has reported positive and negative valence effects in these regions consistently 36 with our findings (Algermissen et al, 2022). Also, outcome-locked vmPFC activity has been shown to scale with greater Pavlovian influence as a function of diminished environmental controllability (Gershman et al, 2021) (Campese et al, 2015;Campese et al, 2017;Kim et al, 2022). Using congruent appetitive PIT paradigms previous neuroimaging studies have found that BOLD activity in the nucleus accumbens (Talmi et al, 2008;Mendelsohn et al, 2014), amygdala (Talmi et al, 2008;Prevost et al, 2012;Mendelsohn et al, 2014) and striatum (Bray et al, 2008;Prevost et al, 2012) is correlated with appetitive PIT effects.…”