Introduction & Objective: The brain choroids plexus (BCP) plays an important role in the cerebrospinal fluid (CSF) production, but its characterization is still incomplete. Collagen type IV, is one of the most important proteins of basement membrane (BM) and extracellular matrix (ECM) of BCP. In the present study we investigated the differential period of type IV collagen in basement membrane of the BCP of mouse fetuses using immunohistochemical method.

Materials & Methods: Intact female balb/c mice were kept under normal conditions. After mating, vaginal plug was assumed as day zero of pregnancy. From days 10 to the last day of pregnancy, the mice were sacrificed and their embryos were collected. For processing, the head of embryos were fixed, serially sectioned and immunohistochemistry study for tracing collagen type IV of BCP were carried out.

Results: This study indicated that collagen IV appeared by weak reaction on day 12 of gestation in BM of primary BCP and increased continuously until day 17th of gestation. After this period, collagen reaction did not show significant changes in the next embryonic days.

Conclusion: Our previous study showed that renal glomeruli development is dependent on the collagen type IV appearance in BM and ECM. So, the present investigation confirmed that the BCP development is also dependent on type IV collagen synthesis in BM of brain ventricular choroids. These data indicated that the specific localization of this protein may be shared by renal glomeruli and the choroid plexus leads us to hypothesize that the type IV collagen protein may function as a selective permeability barrier.