Morphologic study of medial and lateral longitudinal tria

Introduction: There are two thin strips called medial longitudinal stria (MLS) and lateral longitudinal stria (LLS) formed by myelinated fibers embedded in indusium griseum (IG), which is observed over the dorsal length of the corpus callosum (CC). It has been found that there are very few studies on MLS and LLS in the literature reviews. Longitudinal striae (LS) are now considered to be parts of the limbic system. Our goal is examining our samples with light microscopy by staining histologically with Hematoxylin & Eosin (HE), Luxol Fast Blue (LFB) and immunohistochemically with neurofilament after applying the necessary histological procedures. In the light of the data we have obtained, our objective is expand our knowledge about LS, which is especially untouched in terms of histological and functional, and investigate its scientific place. Starting from this point of view, our goal is reveal the morphological features of LS's functional relationship which is supposed to exist with the limbic system and its components to withstand strong reasons. At the same time, to determine whether these histological stains we used to be revised at the present protocols in our study. Materials and Methods: In our study, adult cadaveric brain hemispheres were used that fixed with 10% formaldehyde solution, without macroscopic pathology and unaffected tissue integrity. The obtained tissue samples were taken into Pbs to reduce the effect of fixative. Subsequently, it was placed in a 4% formaldehyde solution, which is more suitable for histological steps. Later, we took the tissue to follow-through. During following the tissue, the tissues were prepared in accordance with transillumination technique and with HE and LFB by light microscopy. After the histological processes were followed, the preparations that prepared and stained were examined at various magnifications in the microscope and their photographs were taken. Findings: LS was detected on the CC during dissection, and histologic processes were initiated after coronal sections were taken. Sections were taken from three different regions that genu, truncus and splenium parts of the corpus callosum. Even if the staining protocols were revised by us, probably the cadaver brains were kept in formaldehyde solution pools for a long time, so satisfied feedback could not be obtained from the three regions. Therefore, the comparison between these sections did not perform. Although repeatedly tried, desired staining outcomes and suitable images from immunohistochemical staining methods using HE and neurofilament protein could not obtain. For this reasons, our study was followed by LFB staining method. After the fixation of the tissue was done, the morphological features of LS were determined using staining methods. In histological staining with LFB, we described that distinguished between LS and CC and IG primarily. Within the LS structure, when compared to IG, visible multipolar neurons were detected. Vascular structures were also seen in this area. It was seen that the nerve fibers and vessels had an extension in the same plane in LS. At the truncus of the CC level, Virchow-Robin space samples were formed around a section of veins taken from CC where they were seen in LS. Discussion and Conclusion: There was not enough brain tissue in our study and most of the existing brains were inadequate in terms of tissue integrity in our workspace. So, a quantitatively limited study was done. Nevertheless, according to us, the absence of such a study before has added a qualitative value to our study. The current application protocols of the histological stains were revised to obtain appropriate feedbacks from sections of the brain tissue exposed to the long-standing formaldehyde solution. In this study, a broad projection of LS, including the anatomic, histological, physiologic and neuroradiological aspects of LS, included in the limbic system were shown. Histologically, CC, IG and LS were detected on the same image for the first time. LS's fibers, vascular and morphological structure were indicated.