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Topic

design image
Subiculum

The subiculum is a key transitional area located between the hippocampus proper (cornu ammonis) and the entorhinal cortex in the medial temporal lobe. As part of the hippocampal formation, the subiculum serves as a critical relay center, channeling information between the hippocampus and various cortical and subcortical structures. Its unique anatomical position and cellular architecture make it essential for memory processing, spatial navigation, and limbic system function.

Synonyms

  • Subicular cortex

  • Subiculum proper

  • Subicular region

  • Subiculum hippocampi

Arterial Supply

  • Primarily supplied by branches of the posterior cerebral artery (PCA), especially the posterior hippocampal arteries

  • Additional contribution from anterior choroidal artery (branch of the internal carotid artery) in some individuals

  • Occasional small branches from the middle cerebral artery (MCA) territory

Venous Drainage

  • Drained by the hippocampal veins

  • These veins empty into the basal vein of Rosenthal

  • Ultimately, venous blood drains into the great cerebral vein (vein of Galen)

Function

  • Major output region of the hippocampal formation

  • Plays a crucial role in:

    • Memory consolidation

    • Spatial navigation

    • Modulation of the hypothalamic-pituitary-adrenal (HPA) axis

    • Relaying processed information from the hippocampus to cortical and subcortical targets

  • Implicated in various neurological and psychiatric conditions (e.g., epilepsy, depression, schizophrenia)

MRI Appearance

  • T1-weighted images:

    • Appears as a thin, hypointense band between the hippocampus and parahippocampal gyrus

  • T2-weighted images:

    • Typically isointense or slightly hyperintense relative to the surrounding hippocampal tissue

    • Good anatomical delineation from adjacent structures

  • FLAIR images:

    • Normally isointense to surrounding gray matter

    • Pathological processes (e.g., gliosis, infarction) may show hyperintensity in this region

CT Appearance

  • Not well visualized on non-contrast CT due to poor soft tissue contrast

  • Appears as part of the medial temporal lobe gray matter; no distinct borders

  • Pathological conditions (e.g., infarct, hemorrhage, calcification) may result in abnormal density changes in the region, but normal subiculum is usually indistinguishable from adjacent hippocampal formation

MRI images

Subiculum mri 3t coronal image