Longitudinal striae
In the eighteenth century, Giovanni Maria Lancisi described the indusium griseum (IG) and the longitudinal striae (LS) of the corpus callosum.
The medial longitudinal striae (nerves of Lancisi) and lateral longitudinal striae are two pairs of myelinated fiber bands found in the gray matter of the IG on the dorsal aspect of the corpus callosum. Embryologically, the IG and LS are dorsal remnants of the archicortex of the hippocampus and fornix and thus they are considered components of the limbic system.
Studies using immunohistochemistry reported that acetylcholine, dopamine, noradrenaline, 5-hydroxytryptamine and GABA neurons innervate the IG. Newer imaging techniques, such as high field MRI and diffusion tensor imaging, provide new tools for studying these structures, whose true function remains still unclear.
Di Ieva in a paper of 2014, reviews the history of the discovery of the IG and LS of the corpus callosum, with a holistic overview on these interesting structures from the anatomical, embryological, neurochemical, radiological and clinical perspective 1).
It continuous laterally with the grey matter of the cingulate gyrus.
It contains two longitudinally directed strands of fibers termed respectively the medial and lateral longitudinal striae (of Lancisi) on each side.
