Key Messages 1. Chronic steroid therapy causes disturbance in cell proliferation of the hippocampus and the subventricular zone. This may be the underlying cause of altered memory and cognitive function. 2. Co-administration of paroxetine (a class of antidepressants) during steroid therapy could counteract the destruction. Modification of the current steroid therapy regimen may be required.

Basal radial glia (bRG) is a recently identified major type of neural stem cell in fetal primate, notably human, neocortex. In this issue of Neuron, Betizeau et al. (2013) now demonstrate that four morphologically distinct bRG subtypes exist in the outer subventricular zone of fetal macaque neocortex, and reveal an unexpected complexity of lineages generating neurons.

The subventricular zone (SVZ) continuously supplies new interneurons that incorporate into pre-existing olfactory bulb circuitry. Khodosevich et al. (2013) show that connective tissue growth factor (CTGF) regulates a multicellular signaling cascade determining the number of postnatally born inhibitory interneurons in odor-activated glomeruli.

Subventricular zone neurogenesis occurs throughout life from rodents to primates, but the existence of a rostral migratory stream of immature neurons in postnatal human brains is controversial. A recent report in Nature (Sanai et al., 2011) identifies two neuronal migratory streams in infant human brains targeting the olfactory bulb and prefrontal cortex.

SIR, in the recent paper by Gudziol et al. (2009), treatment of chronic rhinosinusitis lead to an increase of the olfactory bulb volume over a 3-month period, and they concluded that this was due to the restoration of olfactory function. In this letter, we point out another factor that may affect olfactory bulb volume: neuroinflammation regulated neurogenesis. The olfactory bulb volume is great...

Endogenous neural stem cells become "activated" after neuronal injury, but the activation sequence and fate of endogenous neural stem cells in focal cerebral ischemia model are little known. We evaluated the relationships between neural stem cells and hypoxia-inducible factor-1α and vascular endothelial growth factor expression in a photothromobotic rat stroke model using immunohistochemistry a...

BACKGROUND AND PURPOSE Status epilepticus and cerebral ischemia stimulate persistent neurogenesis in the adult brain, but both conditions cause neuronal damage. We determined whether spreading depression, a common epiphenomenon of these conditions, stimulates persistent neurogenesis. METHODS We analyzed the effect of KCl-induced spreading depression on persistent neurogenesis and the spatio-t...

Corticogenesis is underpinned by a complex process of subcortical neuroproliferation, followed by highly orchestrated cellular migration. A greater appreciation of the processes involved in human fetal corticogenesis is vital to gaining an understanding of how developmental disturbances originating in gestation could establish a variety of complex neuropathology manifesting in childhood, or eve...