Although several studies have examined the subcortical circuitry underlying Pavlovian-to-instrumental transfer (PIT), the role of medial prefrontal cortex in this behavior is largely unknown. Elucidating the cortical contributions to PIT will be key for understanding how reward-paired cues control behavior in both adaptive and maladaptive context (i.e., addiction). Here we use bilateral lesions in a rat model to show that infralimbic prefrontal cortex (ilPFC) is necessary for appropriate expression of PIT. Further, we show that ilPFC mediates this effect via functional connectivity with nucleus accumbens shell (NAcS). Together, these data provide the first demonstration that a specific cortico-striatal circuit is necessary for cue-invigorated reward seeking during specific PIT.Cue-motivated reward seeking often requires integration of instrumental response-outcome (R-O) associations with Pavlovian stimulus-outcome (S-O) associations (Rescorla 1990). Experimentally, this integration can be assessed using the Pavlovian-to-instrumental transfer (PIT) task, which measures the ability of reward-associated stimuli to invigorate instrumental responding, even when the R-O and S -O associations have been acquired independently (Estes 1948;Rescorla and Solomon 1967;Lovibond 1983). PIT tasks can be structured to test the generalized arousing effects of Pavlovian cues on behavior (i.e., general PIT) or to test the transfer of Pavlovian information about a specific reward onto the precise behavior that produces that reward (i.e., specific PIT) (Balleine and Ostlund 2007;Holmes et al. 2010). A growing body of work suggests that the specific form of PIT depends on distinct neural substrates, including the basolateral amygdala (BLA) and nucleus accumbens shell (NAcS) Balleine 2005, 2011). However, in contrast to amygdalo-striatal circuitry, the role of medial prefrontal cortex (mPFC) in these behaviors is unknown. The mPFC integrates affective information and instrumental output to attribute incentive value to stimuli, and is therefore well situated to play a key role in cue-guided behavior (Christakou et al. 2004;Homayoun and Moghaddam 2009). While dorsal regions of mPFC-anterior cingulate cortex (ACC) and prelimbic cortex (plPFC)-are not required for PIT (Cardinal et al. 2003;Corbit and Balleine 2003), a role for the more ventral infralimbic cortex (ilPFC) has not been investigated. IlPFC regulates flexible reward seeking and may facilitate cuecontrolled behavior (Barker et al. 2014). IlPFC sends a dense glutamatergic projection to NAcS, a structure that is itself necessary for specific PIT (Corbit and Balleine 2011), and this projection is known to inhibit inappropriate reward seeking (Vertes 2004;Peters et al. 2008Peters et al. , 2009Bossert et al. 2012). Such behavioral inhibition may also be an important element of specific PIT, as responding is not invigorated by a cue that has been paired with a different reward and response (Cartoni et al. 2013).We therefore hypothesized that ilPFC and its projection to the NAcS are r...