Mitotically active cells that generate neurons and astrocytes are present in multiple regions of the adult mouse hippocampus

Abstract

Previous studies of the adult hippocampus of rodents and primates have reported neuro- and gliogenesis restricted to the region of the dentate gyrus. In the present study, by employing a prolonged bromodeoxyuridine (BrdU) labeling protocol that attempts to account for cytokinetic changes as an animal ages, we have identified mitotically active cells in multiple regions of the hippocampus, especially in Ammon's horn, of the adult mouse. Immediately following the labeling period, the BrdU-labeled cells did not express known markers for neurons and astrocytes. Subsequent analysis at 3-24 weeks after labeling demonstrated BrdU-labeled neurons and glia in these regions of the hippocampus. Although neuro- and gliogenesis in the adult mammalian hippocampus have been reported previously, these results demonstrate that the phenomenon is not limited to the region of the dentate gyrus, but rather extends into Ammon's horn. Furthermore, it suggests that ongoing cell production, albeit discrete and limited in nature, may be widespread in the adult mammalian central nervous system.

Adult Rodent Neurogenic Regions: The Ventricular Subependyma Contains Neural Stem Cells, But the Dentate Gyrus Contains Restricted Progenitors

“…Neuronal clones were not detected in isolates containing the hippocampal region CA3 or posterior lateral ventricle. However, a recent in vivo study detected a relatively small number of mitotically active neuronal cells in CA regions of the adult hippocampus (Rietze et al, 2000).…”

Segregated Expression of AMPA-Type Glutamate Receptors and Glutamate Transporters Defines Distinct Astrocyte Populations in the Mouse Hippocampus

“…Indeed, remaining GFP signal has been observed in glia-derived neurons in the embryonic cortex of Tg(GFAP/GFP) mice (Malatesta et al, 2000). The CA1 region of adult mouse hippocampus still contains mitotically active cells (Rietze et al, 2000). Future work has to reveal whether such GluR cells include the transient, astrocyte-derived cells that function as precursors in the formation of new hippocampal neurons (Seri et al, 2001).…”

Dopamine D3Receptor Agonist Delivery to a Model of Parkinson's Disease Restores the Nigrostriatal Pathway and Improves Locomotor Behavior

“…Although the adult CNS has only limited potential to generate new neurons, discrete regions do retain the capacity for neurogenesis, including the dentate gyrus of the hippocampus (Palmer et al, 1997;Rietze et al, 2000) and the subventricular zone (SVZ), lining the lateral ventricles (Luskin, 1993). More recently, restricted progenitor cells have been identified in various "quiescent" regions of the adult brain including the striatum (Palmer et al, 1995;Pencea et al, 2001) and the SN (Lie et al, 2002;Zhao et al, 2003;Shan et al, 2006).…”