Cell formation in the cortical layers of the developing human cerebellum

Abstract

Cell proliferation has been studied in the human cerebellar cortex between the 24th gestational week and the 12th postnatal month. Intensive cell formation has been found in the external granular layer (EGL) of the human cerebellum, where the highest cell proliferation rate occurs between the 28th and 34th gestational weeks. This is followed by a gradual decrease that lasts up to the eighth postnatal month. As late in development as the fifth postnatal month, still 30% of cells of the EGL are labeled with the monoclonal antibody Ki-67, which is specific for dividing cells. The width of the EGL remained unchanged from the 28th gestational week to the end of the first postnatal month, when it starts to decrease and completely disappears by the 11th postnatal month. Large number of Ki-67 labeled cells occurs in the internal granular layer (IGL) between the 24th and 28th gestational weeks. From the 36th week onwards, the labeling index is less than 1%, although a few labeled cells have always been found in this layer even in the late postnatal period. Labeled cells are distributed in the entire width of the IGL. However, from the 34th gestational week, almost all labeled cells are found among and directly below the Purkinje cells. Their position, the nuclear features, and their occasionally stained cell processes suggest that those are Bergmann glial cells. There are few Ki-67 labeled cells in the molecular layer (ML) and in the white matter (WM) of the cerebellum throughout the examined period. It is likely that most of these are glial cells. Pyknotic index has been found to be small in all layers of the cerebellum during the examined period.

Characterization of signaling function and expression of HLA class I molecules in medulloblastoma

“…The cells of the external granular layer migrate into the inner layers. In the first postnatal year, the width of the external granular layer begins decreasing until it finally disappears around the 11th postnatal month [23, 24]. All four components of MHC class I were expressed only in the prenatal cerebellum, while later in development, at least one of the components was missing (Table 2).…”

Correlation between calbindin expression in granule cells of the resected hippocampal dentate gyrus and verbal memory in temporal lobe epilepsy

“…Following deparaffinization and rehydration of the sections, microwave antigen retrieval was performed as described previously [55,56]. Briefly, following washes with TB three times for 10 min, the slides were placed in 80-ml plastic jars filled with citrate buffer (pH 6.0) and heated in a microwave oven (Optiquick Compact, Moulinex) operating at a frequency of 2.45 GHz and 800 W power setting.…”

Is it possible to improve neurodevelopmental abnormalities in Down syndrome?

“…In rodents, the bulk of DG neurogenesis takes place in the early postnatal period and continues at a slower rate into adulthood. Neurons of the cerebellum are mainly formed prenatally, with the exception of the granule cells of the inner granular layer that are formed both prenatally and in the early postnatal period from precursors in the external granular layer (EGL; Abraham et al, 2001 ;Sudarov and Joyner, 2007 ). Neurogenesis alterations in the VZ, SVZ, SGZ and EGL have been documented in the DS brain.…”