RESUMEN
Objective: This study is to observe ultrastructurally of the pineal gland from cadaveric embalmed specimens by light microscopy (LM) and transmission electron microscopy (TEM) Methods: Ten pineal glands were removed from cadaveric embalmed specimens. Each pineal gland was disected into two groups, one was put into 10% formaldehyde and the other was put into 2.5% glutaraldehyde. The first group was processed for light microscopy. First of all, fixed the tissues in formalin and then embedded in paraffin. Next, serially sectioned at eight micron and finally stained. Staining methods were (i) haematoxylin and eosin, (ii) Masson-Fontana method for melanin. The second group well preserved in 2.5% glutaraldehyde was chosen to prepare for the TEM. Results: Only five out of ten cadaveric pineal glands viewed by light microscopy were well preserved. In LM, we saw clearly that all ultrastructures or morphology of the cadaveric embalmed pineal gland cells were the same as the standard textbook. Melanin pigments were accumulated in both of the cytoplasm of pinealocytes and the stroma of pineal gland proved by Masson-Fontana staining. Mast cells were found throughout the gland but preferably found in the connective tissue trabeculae. A neuronal-like cell was found in the parenchyma of pineal gland. Extrapineal and intrapineal calcified concretion called corpora arenacea or brain sand were presented. Intrapineal concretions in the parenchyma were globular and concentric lamellar patterns while extrapineal concretions which were adjacent to the capsule were concentric lamellar only. TEM of pineal gland showed that it was moderately preserved in the chemical fixative of this formula. Cadaveric pinealocyte showed some organelles and chromatin extraction while the environmental fibrillar structures were well preserved. Conclusion: The histological findings in the pineal glands from cadaveric embalmed specimens are similar to fresh cadavers. Moreover, they can be used to prepare the normal slides for Histology Lab of the second year medical students. The presences of the melanin pigments in the cytoplasm of pinealocytes and stroma, mast cells, corpora arenacea, and neuronal-like cells confirm the previous studies.
RESUMEN
Objective: To demonstrate the occipital crus of the fornix from the brain of Thai cadavers and provide here the first finding and the first report. Methods: 10 brains of Thai cadavers, 5 males and 5 females, were bisected. Each half was further dissected to demonstrate the inferior horn, the body and the collateral trigone of the lateral ventricle by removing the cerebrum from the superior part down and backwards. The dissection also removed the body of the corpus collasum and left only the splenium portion. When exposing the inferior horn and the collateral trigone, the hippocampal formation was situated at the inferomedial aspect. We can see the fornix arises from the fimbria of the hippocampus and curves anteriorly to terminate at the mammilary body and the septal nuclei. Another 15 sets of horizontal brain sections and 15 sets of coronal brain sections also helped in confirming this report. The sections passed through the crus of the fornix were selected and observed. Results: We can define and demonstrate another crus of the fornix, which arises from the occipital lobe of the brain, the occipital crus. This crus may arrange in a round elevated bundle or a flat bundle beneath the ependyma and join the posterior part of the hippocampal crus of the fornix at the medial border of the body of the lateral ventricle. Conclusion: The fornix is the fiber which originates from the hippocampal formation to be the fimbria and leaves the hippocampus as the crus part of the fornix. Then it curves superiorly anteriorly and inferiorly to terminate at the septal nuclei and the mammillary body. Another crus of the fornix comes from the occipital cortex posteriorly and joins together with the hippocampal crus to terminate in the same area. This suggests that the occipital crus of the fornix involves in another part of the limbic structures that are responsible for the memory consolidation, emotions and autonomic responses.