Dopamine and noradrenaline efflux in the rat prefrontal cortex after classical aversive conditioning to an auditory cue

We used bilateral microdialysis in the medial prefrontal cortex (PFC) of aw ake, freely moving rats to study aversive conditioning to an auditory cue i n the controlled environment of the Skinner box. The presentation of the ex plicit conditioned stimuli (CS), previously associated with foot shocks, ca used increased dopamine (DA) and noradrenaline (NA) efflux. This conditione d response was dependent on the immediate pairing of the two stimuli; in th e pseudoconditioned group that received an equal number of both stimuli, bu t in an unpaired fashion, no conditioned increases in efflux were observed.