p559fig15.27 Brain regions and processes that contribute to the release of dopaminergic Now Print signals by the substantia nigra pars compacta, or SNc, in response to unexpected reinforcing events.  See the text for details.<BR>||  Model of spectrally timed SNc learning (Brown, Bulloch, Grossberg 1999).  Delayed inhibitory expectations of reward.  Dopamine cells signal an error in reqard prediction timing or magnitude.  Immediate excitatory predictions of reward.  Lateral hypothalamus (Primary Reward Input)-> [(+)ventral striatum <-> ventral pallidium (+)-> PPTN(+)-> SNc].  SNc-> [dopamine signal -> ventral striatum, Striosomal cells].  Conditioned Stimuli (CS)(+)-> [ventral striatum, striosomal cells].  Striosomal cells(-)-> SNc.