Cerebellum cell proliferation

Oral gavage of rat pups with 14mg/kg/day ftom posmatal day 5 through 20 caused reductions in serum thyroxine levels that correlated with depressed behavioral parameters. Further studies using the same protocol reported decreased cell proliferation in the cerebellum and forebrain on postnatal days 11 and 21, respectively. In yet another study, 14mg/day of chlorine dioxide on posmatal days 1-20 was associated with some neurotoxicity (decreased forebrain weight and reduced synapse formation on day 35), but the neurotoxicity was not correlated with any antithyroid activity of this chemical. ... 

Wallace VA (1999) Purkiiije-ce 11-derived sonic hedgehog regulates granule neui on precursor cell proliferation in die developing mouse cerebellum. Cuit Biol 9 445 448. 

In primary cultures from developing rat or mouse cerebellum no such effects on proliferation of EGL cells has been demonstrated (Messer et al. 1984, 1985), although effects on the number of glial cells were found. However, it is not clear whether proliferation of EGL cells occurs at sufficient levels in these cultures to show effects even if they were present. Thus, this issue must await further clarification. Also there is some question as to whether all postnatal germinal zones respond to thyroid hormones in the same way (Seress, 1977, 1978). However, the presence of specific nuclear receptors for thyroid hormones during brain development, (see Chapter by DeNayer) is consistent with the possibility that effects of thyroid hormones on cell proliferation, where they do exist, could occur by direct interactions with the genome. 

Fujita, S. (1967) Quantitative analysis of cell proliferation and differentiation in the cortex of the postnatal mouse cerebellum. J. Cell. Biol. 32, 277-287. 

In other brain regions such as the cerebellum, there are cells simultaneously undergoing proliferation, differentiation, migration, and apoptosis. Thus, the contribution of these basic cellular processes to organ development can vary temporally across organ regions and in relation to each other. 

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