164 LeDOUX areas interferes with contextual conditioning(Maren&Fanselow 1995.Majidi- shad et al 1996).Hippocampal projection to B and AB thus seem to be involved Tone CS Smui Context CS B Aa eus of the amygdala (CE).In con ning to the app ratus hy the hi and the hippocampus and the ba ur project to CE.As (Bd oning164 LeDOUX LA CE B AB Auditory Stimulus Brainstem Fear Reaction LA CE B Brainstem Fear Reaction Contextual Stimulus Hippocampus Tone CS Context CS AB Figure 4 Conditioning to a tone [conditioned stimulus (CS)] involves projections from the auditory system to the lateral nucleus of the amygdala (LA) and from LA to the central nucleus of the amygdala (CE). In contrast, conditioning to the apparatus and other con￾textual cues present when the CS and unconditioned stimulus are paired involves the representation of the context by the hippocampus and the communication between the hippocampus and the basal (B) and accessory basal (B) nuclei of the amygdala, which in turn project to CE. As for tone conditioning, CE controls the expression of the responses. areas interferes with contextual conditioning (Maren & Fanselow 1995, Majidi￾shad et al 1996). Hippocampal projection to B and AB thus seem to be involved in contextual conditioning (for a comparison of the amygdala pathways involved in conditioning to a tone CS and to a context, see Figure 4)