DNA synthesis experimentally induced in neurons: Tetraploidy or hyperdiploidy?

Abstract

DNA synthesis triggered in Auerbach's plexus neurons by hypertrophy of muscular territory is related to a condition of hyperdiploidy.

Postnatal histogenesis in the peripheral nervous system

“…not followed by cell division) occurs in some myenteric neurons from the hypertrophic loops. In fact, while autoradiography after 3 H-thymidine administration and PCNA immuno-staining showed the presence DNA neosynthesis in myenteric neurons (Giacobini-Robecchi et al, 1985, 1988Poncino et al, 1991;Corvetti et al, 2001) cytophotometry after Feulgen staining suggested that this neosynthesis not associated with cell division but with a hyperdiploid DNA content (Giacobini-Robecchi et al, 1988;Poncino et al, 1991). In addition, electrophoretic analysis of the total genomic DNA extracted from myenteric ganglia isolated from hypertrophic loops have shown the presence of extra-bands migrating below the high molecular weight DNA, suggesting that DNA amplification can be the mechanism of the observed unscheduled DNA synthesis (Giacobini-Robecchi et al, 1995).…”

DNA Replication and Related Cellular Processes

“…In a series of studies, Giacobini-Robecchi and coworkers showed the presence of DNA replication (by autoradiography after 3H-thymidine administration and PCNA immuno-staining) in myenteric neurons from the small intestine loops upstream from a partial stenosis (Corvetti et al 2001;Poncino et al 1990;Giacobini Robecchi et al 1988). However, cytophotometry after Feulgen staining showed that myenteric neuron DNA replication might not be due to a tetraploid DNA content related to cell division, but instead to unscheduled DNA synthesis that leads to a hyper diploid DNA content (Poncino et al 1990;Giacobini Robecchi et al 1988). Electrophoretic analysis of total genomic DNA has also suggested that unscheduled DNA synthesis can be due to DNA amplification (Giacobini Robecchi et al 1995).…”

The Enteric Nervous System in Intestinal Inflammation

“…HUMAN STUDIES The original observation of increased ganglion cells in the ENS in IBD not only established a neural involvement in these diseases but also initiated a controversy: how can there be more enteric neurons if they are postmitotic? This has not been resolved, but evidence suggests that adult enteric neurons (at least in animals) have a remarkable plasticity of form and the capacity for growth and active DNA synthesis (46,47). Although cell division in adult neurons seems unlikely, it cannot be completely excluded as a possibility; a study in humans found that the number of centrioles in neurons of the submucous plexus was increased in patients with Crohn's disease (48), which may indicate mitosis.…”