Colony-forming ectopic granule cells in the cerebellar primary fissure of normal adult rats: a morphologic and morphometric study

doi:10.1016/0006-8993(88)91473-4

Brain Research

Volume 439, Issues 1–2, 26 January 1988, Pages 169-178

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Abstract

The morphology and degree of maturation of intrafissural colony-forming ectopic granule cells (EGCs) were investigated in the cerebella of normal adult rats. These EGCs exhibit a notable degree of morphological maturity, with 2–5 short dendrites radiating from a globular soma, typical dendritic claw-like terminals and descending axons. The EGCs receive the afferent input of mossy fiber terminals and their axons also establish homologous synapses with the postsynaptic dendritic spines of the Purkinje cells. Although these EGCs exhibit the typical morphology of mature granule cells, the morphometric analysis shows, however, a significant reduction in the number of dendrites (mean 3.30 ± 0.60) and ‘claws’ (mean 3.66 ± 0.12) in the EGCs with respect to the controls (means 3.85 ± 0.73 and 4.53 ± 0.13, respectively). These differences may be indicative of a slight numerical mismatching between EGCs and afferent mossy fibers, which limit the input that the ectopic neurons receive. The karyometric study also showed that the average nuclear area in EGCs was significantly smaller (mean 19.38 ± 0.24 μm²) than in controls (mean 21.88 ± 0.24 μm²), suggesting a positive correlation between nuclear size and the number of postsynaptic dendritic terminals available in the granule cells. The influence of some morphogenetic factors on the degree of maturity attained by these ectopic neurons is discussed, particularly the interactions of mossy fibers and astrocytes with maturing EGCs.

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Research reportColony-forming ectopic granule cells in the cerebellar primary fissure of normal adult rats: a morphologic and morphometric study

Abstract

Neuroscience

Brain Research

Brain Research

Brain Research

Neuroscience

Brain Research

Brain Research

Morphological development in the rat cerebellum and some of its mechanisms

Astroglial organization in ectopic foci of granule cells within rat cerebellar fissures

Neurosci. Lett. Suppl.

Elementos de Técnica Micrográfica del Sistema Nervioso

Mechanisms of cortical development: a view from mutations in mice

Ann. Rev. Neurosci.

Arrested granule cells and their synapses with mossy fibers in the molecular layer of the cerebellar cortex

Z. Anat. Entwickl. Gesch.

Naturally occuring alterations of cortical layers surrounding the fissura prima of rat cerebellum

J. Comp. Neurol.

Research report
Colony-forming ectopic granule cells in the cerebellar primary fissure of normal adult rats: a morphologic and morphometric study