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Topic

design image
Dentate gyrus

The dentate gyrus is a key structure within the hippocampal formation of the brain, located in the medial temporal lobe. Recognized for its distinct, serrated appearance, it plays a vital role in memory formation and cognitive function. The dentate gyrus is involved in neurogenesis and acts as a gateway for incoming information to the hippocampus, contributing to learning, pattern separation, and spatial memory.

Synonyms

  • Dentate convolution

  • Fascia dentata

Arterial Supply

  • Supplied primarily by branches of the posterior cerebral artery (PCA), specifically:

    • Posterior choroidal arteries

    • Hippocampal branches of the PCA

  • Occasionally receives blood from the anterior choroidal artery

Venous Drainage

  • Venous blood drains mainly into the:

    • Great cerebral vein (vein of Galen)

    • Inferior ventricular vein

    • Basal vein of Rosenthal

  • Ultimately connects to the straight sinus

Function

  • Critical for formation of new episodic memories

  • Pattern separation: helps distinguish similar experiences and inputs

  • Involved in spatial memory and navigation

  • Site of adult neurogenesis (generation of new neurons throughout life)

  • Acts as a “gatekeeper” for information entering the hippocampal circuit

MRI Appearance

  • T1-weighted images:

    • Appears as a thin, curved, hypointense (dark) band along the superior aspect of the hippocampus

  • T2-weighted images:

    • Slightly hyperintense (bright) compared to surrounding hippocampal tissue

    • Outlines as a curved, well-demarcated structure

  • FLAIR sequences:

    • Follows T2 characteristics; typically isointense or slightly hyperintense

    • No abnormal high signal unless pathology present

CT Appearance

  • Not well visualized due to limited soft tissue contrast

  • Appears as a small, indistinct gray matter region adjacent to the hippocampus

  • Pathology (such as sclerosis or calcification) may render it slightly more conspicuous

MRI images

Dentate gyrus mri 3t coronal image

MRI images

Dentate gyrus mri 3t coronal sagittal