%0 Journal Article
%T Nucleus accumbens corticotropin-releasing factor increases cue-triggered motivation for sucrose reward: paradoxical positive incentive effects in stress?
%A Susana Peci£¿a
%A Jay Schulkin
%A Kent C Berridge
%J BMC Biology
%D 2006
%I BioMed Central
%R 10.1186/1741-7007-4-8
%X Microinjections of the highest dose of CRF (500 ng) or amphetamine (20 ¦Ìg) selectively enhanced the ability of Pavlovian reward cues to trigger phasic peaks of increased instrumental performance for a sucrose reward, each peak lasting a minute or so before decaying after the cue. Lever pressing was not enhanced by CRF microinjections in the baseline absence of the Pavlovian cue or during the presentation without a cue, showing that the CRF enhancement could not be explained as a result of generalized motor arousal, frustration or stress, or by persistent attempts to ameliorate aversive states.We conclude that CRF in nucleus accumbens shell amplifies positive motivation for cued rewards, in particular by magnifying incentive salience that is attributed to Pavlovian cues previously associated with those rewards. CRF-induced magnification of incentive salience provides a novel explanation as to why stress may produce cue-triggered bursts of binge eating, drug addiction relapse, or other excessive pursuits of rewards.Corticotropin-releasing factor (CRF) is involved in mediating the physiological and behavioral responses to stress [1-5]. Beyond activating aversive behaviors, stress also increases some appetitive behaviors. For example, food intake and relapse into drug-taking in models of addiction are both increased by natural CRF-releasing stressors [6-11]. Such appetitive behaviors have often been viewed as attempts to reduce or avoid unpleasant stress or as overflow from general motor arousal or frustration ([12-14] but see [8-11]).However, despite the traditional association of CRF with aversive stress, some CRF brain systems also are activated by positive rewards, even in the absence of conventional stressors. For example, CRF release is increased in the central nucleus of the amygdala by spontaneous food ingestion [10,15] and in prefrontal cortex by presentation of Pavlovian cues associated with food reward [10]. Similarly, sucrose ingestion normalizes CRF levels
%U http://www.biomedcentral.com/1741-7007/4/8