Foot shock facilitates reward seeking in an experience-dependent manner

Abstract

Animals organize reward seeking around aversive events. An abundance of research shows that foot shock, as well as a shock-associated cue, can elicit freezing and suppress reward seeking. Yet, there is evidence that experience can flip the effect of foot shock to facilitate reward seeking. Here we examine cue suppression, foot shock suppression and foot shock facilitation of reward seeking in a single behavioural setting. Male Long Evans rats received fear discrimination consisting of danger, uncertainty and safety cues. Discrimination took place over a baseline of rewarded nose poking. With limited experience, all cues and foot shock strongly suppressed reward seeking. With continued experience, suppression became specific to shock-associated cues and foot shock facilitated reward seeking. Our results provide a means of assessing positive properties of foot shock, and may provide insight into maladaptive behavior around aversive events.

A fear conditioned cue orchestrates a suite of behaviors

“…Supporting the minimization of defensive behavior in reward settings, foot shocks signaled by danger will strongly suppress reward seeking only early in fear conditioning. Shock-induced suppression quickly wanes and with experience, shock delivery will paradoxically facilitate reward seeking (Strickland et al, 2021). Shock timing information is readily apparent in the ventrolateral periaqueductal gray, a brain region central to defensive behavior (Fanselow, 1993; Carrive et al, 1997; Mobbs et al, 2007; McDannald, 2010; Tovote et al, 2016; Arico et al, 2017).…”

Foot shock facilitates reward seeking in an experience-dependent manner

“…A shock-associated cue will sharply reduce reward seeking. Historically termed a conditioned emotional response [2][3][4][5] , now commonly termed conditioned suppression, the ability of a shock-associated cue to suppress reward seeking has been observed in many settings and laboratories [6][7][8][9][10][11][12][13][14][15][16] .…”