a Dorsal b Dorsal c Dorsal * * * * * * * Medial * Lateral Medial * * Lateral Medial Lateral Ventral Ventral Ventral d CA2 e f Fimbria CA3 CA2 CA3 Uncus Fimbria CA4 Fimbria CA1 Uncus CA4 CA1 Uncus CA3/2 DG DG DG/CA4 CA1 Pre/ parasubiculum Prosubiculum/ Prosubiculum/ subiculum Pre/parasubiculum Pre/parasubiculum Prosubiculum/ subiculum subiculum Subregions Important Landmarks DG/CA4 CA3/2 Vestigial Hippocampal Sulcus (VHS) Uncus CA1 Fimbria / Dorsal Wall of the Hippocampus Prosubiculum/subiculum * - Islands Indicating Presubiculum Pre/parasubiculum Uncus Figure 1 Figure 2 Dorsal a b c d e f Posterior Medial Lateral DG/CA4 CA1 Pre/parasub Anterior CA3/2 Prosub/sub Uncus Ventral Figure 3 Legend Subregions US - Uncul Sulcus a DG/CA4 VHS - Vestigial Hippocampal Sulcus > - Dorsal Extent of VHS CA3/2 ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria # - Dorsolateral Extent of Lateral Uncul Sulcus / Pre/parasubiculum Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal 7 7 7 6 6 ! ! 6 ! Medial Lateral Medial Lateral Medial Lateral 2 2 2 Ventral Ventral Ventral e f g Lateral External Digitation 7 Lateral External Digitation 6 4 5 Figure 4 Legend Subregions US - Uncul Sulcus a DG/CA4 VHS - Vestigial Hippocampal Sulcus > - Dorsal Extent of VHS CA3/2 ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria # - Dorsolateral Extent of Lateral Uncul Sulcus / Pre/parasubiculum Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal 7 7 7 ! * * ! * ! * * * * * VHS > Medial Lateral Medial Lateral Medial 2 Lateral VHS > VHS > VHS VHS 2 2 Ventral Ventral Ventral e f g Lateral External Digitation Lateral External Digitation Figure 5 US - Uncul Sulcus Legend Subregions a VHS - Vestigial Hippocampal Sulcus DG/CA4 HATA Hippocampo-amygdalar Transition Area CA3/2 > - Dorsal Extent of VHS ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria Pre/parasubiculum # - Dorsolateral Extent of Lateral Uncul Sulcus / Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal ! 7 ! 7 > 7 ! US > CSF > VHS Medial Lateral Medial * VHS Lateral Medial VHS Lateral * VHS * ^ 2 * VHS VHS ^ 2 ^ 2 Ventral Ventral Ventral e g Lateral External Digitation f Lateral External Digitation 8 7 DG 4 : : : 6 5 Figure 6 US - Uncul Sulcus Legend Subregions a VHS - Vestigial Hippocampal Sulcus DG/CA4 HATA Hippocampo-amygdalar Transition Area CA3/2 > - Dorsal Extent of VHS ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria Pre/parasubiculum # - Dorsolateral Extent of Lateral Uncul Sulcus / Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal ! 7 ! > VHS > VHS ! US 7 7 VHS CSF > Medial Lateral Medial Lateral Medial VHS Lateral * 2 * * ^ * * ^ VHS * ^ VHS 2 2 Ventral Ventral Ventral e f g Lateral External Digitation Lateral External Digitation 8 7 1 : : : Figure 7 US - Uncul Sulcus Legend Subregions a VHS - Vestigial Hippocampal Sulcus DG/CA4 HATA Hippocampo-amygdalar Transition Area CA3/2 > - Dorsal Extent of VHS ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria Pre/parasubiculum # - Dorsolateral Extent of Lateral Uncul Sulcus / Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal 7 ! ! > VHS 7 > VHS ! CSF US 7 > VHS VHS Medial Lateral Medial Lateral Medial ^ 2 Lateral * * * * ^ VHS * * ^ VHS 2 2 Ventral Ventral Ventral e Lateral External Digitation f g Lateral External Digitation 8 7 : : : Figure 8 US - Uncul Sulcus Legend Subregions a VHS - Vestigial Hippocampal Sulcus DG/CA4 HATA Hippocampo-amygdalar Transition Area CA3/2 > - Dorsal Extent of VHS ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria Pre/parasubiculum # - Dorsolateral Extent of Lateral Uncul Sulcus / Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal ! ! > VHS > VHS ! US CSF 7 >VH S # Medial # Lateral Medial Lateral Medial VHS Lateral * * * VHS # ^ 2 ^ * ^ VHS 2 * * 2 Ventral Ventral Ventral e Lateral External Digitation f g Lateral External Digitation 8 7 : : Figure 9 Legend Subregions US - Uncul Sulcus a DG/CA4 VHS - Vestigial Hippocampal Sulcus > - Dorsal Extent of VHS CA3/2 ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria # - Dorsolateral Extent of Lateral Uncul Sulcus / Pre/parasubiculum Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal ! ! > VHS > VHS ! US CSF > # VHS # # Medial Lateral Medial * Lateral Medial ^ VHS Lateral * * * * * ^ VHS * * * * ^ VHS 2 2 2 Ventral Ventral Ventral e Lateral External Digitation f g Lateral External Digitation : : Figure 10 Legend Subregions US - Uncul Sulcus a DG/CA4 VHS - Vestigial Hippocampal Sulcus > - Dorsal Extent of VHS CA3/2 ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria # - Dorsolateral Extent of Lateral Uncul Sulcus / Pre/parasubiculum Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal ! ! CSF VHS > VHS > (dark patch = blood vessel) US # # ! # >VH S * ^ Medial * * * VHS Lateral Medial * Lateral Medial VHS Lateral * * * ^ VHS ^ 2 2 2 Ventral Ventral Ventral e Lateral External Digitation f g Lateral External Digitation : : Figure 11 Legend Subregions US - Uncul Sulcus a DG/CA4 VHS - Vestigial Hippocampal Sulcus > - Dorsal Extent of VHS CA3/2 ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria # - Dorsolateral Extent of Lateral Uncul Sulcus / Pre/parasubiculum Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal % ! ! > VHS > VHS # % ! # % * * # > * * * ^ VHS * ^ VHS * VHS * * ^ VHS Medial Lateral Medial * 2 Lateral Medial 2 Lateral 2 Ventral Ventral Ventral e f g % : : Figure 12 Legend Subregions US - Uncul Sulcus a DG/CA4 VHS - Vestigial Hippocampal Sulcus > - Dorsal Extent of VHS CA3/2 ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria # - Dorsolateral Extent of Lateral Uncul Sulcus / Pre/parasubiculum Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus Dorsal Dorsal d Dorsal b c ! % ! % # % ! # # VHS > >VH S ^ VHS >VH S Medial * * Lateral Medial * * ^ Lateral Medial Lateral ^ VHS VHS Ventral Ventral Ventral e f g : Figure 13 Legend Subregions US - Uncul Sulcus a DG/CA4 VHS - Vestigial Hippocampal Sulcus > - Dorsal Extent of VHS CA3/2 ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria # - Dorsolateral Extent of Lateral Uncul Sulcus / Pre/parasubiculum Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal % Dorsal portion of hippocampus Dorsal portion of % % hippocampus ! # % # Dorsal portion of # ! hippocampus Medial > Lateral Medial Lateral Medial ^ VHS > Lateral ^ VHS > VHS VHS ^ VHS VHS Ventral Ventral Ventral e f g % % : Figure 14 Legend Subregions US - Uncul Sulcus a DG/CA4 VHS - Vestigial Hippocampal Sulcus > - Dorsal Extent of VHS CA3/2 ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria # - Dorsolateral Extent of Lateral Uncul Sulcus / Pre/parasubiculum Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal Dorsal portion of hippocampus DG Dorsal portion of Dorsal portion of hippocampus hippocampus VHS VHS Medial Lateral Medial Lateral Medial Lateral Ventral Ventral Ventral e f g 9 DG : : 10 Figure 15 Legend Subregions US - Uncul Sulcus a DG/CA4 VHS - Vestigial Hippocampal Sulcus > - Dorsal Extent of VHS CA3/2 ^ - Ventral Extent of VHS CA1 * - Islands indicating Presubiculum Prosubiculum/subiculum % - Fimbria # - Dorsolateral Extent of Lateral Uncul Sulcus / Pre/parasubiculum Ventromedial Extent of the Fimbria Uncus ! Medial Extent of the Lateral External Digitation Vestigial Hippocampal Sulcus b Dorsal c Dorsal d Dorsal Medial Lateral Medial Lateral Medial Lateral Ventral Ventral Ventral Isthmus/retrosplenial cortex e Isthmus/retrosplenial cortex f g Dorsal portion of Isthmus/retrosplenial cortex hippocampus a b c d e f 12 7 11 Subregions Uncus 12 7 Prosubiculum/subiculum 11 CA1 Pre/parasubiculum Wall of the Anterior Figure 16 Hippocampus / VHS Anterior - Posterior Figure 17 Examples of VHS Cavities Example of the Ventral Extension of the VHS a c d Ventral extension of VHS VHS cavity Ventral extension of VHS Subregions b e f DG/CA4 CA3/2 CA1 Prosubiculum/subiculum VHS cavity Pre/parasubiculum Uncus Vestigial Hippocampal Sulcus / Ventral Extension