Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
, 74 (6), 868-74

Constitutive Expression of p21H-Ras(Val12) in Neurons Induces Increased Axonal Size and Dendritic Microtubule Density in Vivo

Affiliations
Comparative Study

Constitutive Expression of p21H-Ras(Val12) in Neurons Induces Increased Axonal Size and Dendritic Microtubule Density in Vivo

Gudrun Seeger et al. J Neurosci Res.

Abstract

The small G protein p21Ras is a key signal transducer mediating cellular growth and proliferation responses to extracellular stimuli. We investigated by electron microscopy the effects of augmented p21Ras activity on neuronal processes and microtubule arrangement in vivo. We used transgenic mice with a neuron-specific overexpression of p21H-RasVal12, which starts postnatally around Day 15. Axonal and dendritic diameters and the numerical density of dendritic microtubules were analyzed at postnatal Day 12 before the onset of transgene expression and in adult mice. In adult transgenic mice, calibers of both axons (corpus callosum) and dendrites (layers II/III of somatosensory cortex) were enlarged by about 57% and 79%, respectively. The increase in dendritic calibers was associated with an increment in the amount of microtubules. Even in dendrites of equivalent diameters, the number of microtubules was higher in transgenic mice compared to that in wild-type mice suggesting an elevated microtubule density. Changes in process diameters or microtubule density were not observed at postnatal Day 12 before relevant transcription of transgenic p21H-RasVal12. The present results extend previous findings on neuronal hypertrophy as a consequence of p21H-RasVal12 expression and suggest a profound influence on the dendritic microtubule network.

Similar articles

See all similar articles

Cited by 1 PubMed Central articles

  • Neurodevelopmental Aspects of RASopathies
    YE Kim et al. Mol Cells 42 (6), 441-447. PMID 31250618. - Review
    RAS gene mutations are frequently found in one third of human cancers. Affecting approximately 1 in 1,000 newborns, germline and somatic gain-of-function mutations …

Publication types

MeSH terms

LinkOut - more resources

Feedback