p560fig15.29 Excitatory pathways that support activation of the SNc by a US and the conditioning of a CS to the US.<BR>||  Excitatory pathway.  Primary reward (apple juice) briefly excites lateral hypothalamus.  Hypothalamic-PPTN excitation causes SNc dopamine burst.  Hypothalamic activity excites ventral striatum for training.  Active CS working memory signals learn to excite ventral striatum.  Lateral hypothalamus (Primary Reward Input)-> [(+)ventral striatum <-> ventral pallidium(+)-> PPTN(+)-> SNc].  SNc-> [dopamine signal -> ventral striatum.  Conditioned Stimuli working memory trace (CS)(+)-> ventral striatum.