B Fimbria A CA3 CA2 CA3 pyramidal cell Alveus Granule cell CA4 CA1 pyramidal cell CA1 8 Subiculum Alvear path Perforant path Entorhinal cortex Collateral sulcus Figure 29.6(A)The four sectors of Ammon's horn.(B)Input-output connections of the hippocampal formation. 1 Afferent from sensory association cortex. 2 Entorhinal cortex projecting perforant path fiber to dentate gyrus. 3 Dentate granule cell projecting to CA3. 4 CA3 principal neuron projecting into fimbria and CA1. 5 CA1 principal cell projecting to subiculum. 6 Subicular principal cell projecting into fimbria. 7 Subicular principal cell projecting into entorhinal cortex. 8 Entorhinal pyramidal cell projecting to sensory association cortex