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Modulation of cell-cycle dynamics is required to regulate the number of cerebellar GABAergic interneurons and their rhythm of maturation
- Publication Year :
- 2011
-
Abstract
- The progenitors of cerebellar GABAergic interneurons proliferate up to postnatal development in the prospective white matter, where they give rise to different neuronal subtypes, in defined quantities and according to precise spatiotemporal sequences. To investigate the mechanisms that regulate the specification of distinct interneuron phenotypes, we examined mice lacking the G1 phase-active cyclin D2. It has been reported that these mice show severe reduction of stellate cells, the last generated interneuron subtype. We found that loss of cyclin D2 actually impairs the whole process of interneuron genesis. In the mutant cerebella, progenitors of the prospective white matter show reduced proliferation rates and enhanced tendency to leave the cycle, whereas young postmitotic interneurons undergo severe delay of their maturation and migration. As a consequence, the progenitor pool is precociously exhausted and the number of interneurons is significantly reduced, although molecular layer interneurons are more affected than those of granular layer or deep nuclei. The characteristic inside-out sequence of interneuron placement in the cortical layers is also reversed, so that later born cells occupy deeper positions than earlier generated ones. Transplantation experiments show that the abnormalities of cyclin D2–/– interneurons are largely caused by cell-autonomous mechanisms. Therefore, cyclin D2 is not required for the specification of particular interneuron subtypes. Loss of this protein, however, disrupts regulatory mechanisms of cell cycle dynamics that are required to determine the numbers of interneurons of different types and impairs their rhythm of maturation and integration in the cerebellar circuitry.
- Subjects :
- Cerebellum
genetic structures
Interneuron
cyclin D2
Biology
Mice
Cyclin D2
neuronal specification
neurogenesis in the cerebellum
Cell Movement
Interneurons
medicine
Animals
Molecular Biology
gamma-Aminobutyric Acid
Progenitor
Mice, Knockout
musculoskeletal, neural, and ocular physiology
Neurogenesis
Cell Cycle
Brain
Anatomy
Cell cycle
Transplantation
Mice, Inbred C57BL
medicine.anatomical_structure
nervous system
GABAergic
Neuroscience
Developmental Biology
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....43b3e080e5ac708413bc249063ca32dc