Internal medullary lamina of thalamus

The internal medullary lamina of thalamus refers to a vertical sheet of myelinated white matter fibers. It lies within the thalamus and splits up the gray matter of the thalamus into various sub-parts. The shape of the lamina resembles a Y, with a central stem posteriorly that splits into its two limbs antero-superiorly. Thus, the gray matter of thalamus gets sub-divided into medial and lateral groups of nuclei on either side of the stem of the Y, while an additional anterior group of nuclei can be prominently seen in between the two anterior limbs of the Y.

The internal medullary lamina of thalamus contains intralaminar nuclei. Several nerve fibers traverse through the lamina to interconnect various thalamic nuclei with each other.