Enriched environment and Mash1 transfection affect neural stem cell differentiation after transplantation into the adult somatosensory cortex.

Neural stem cell (NSC) transplantation is a promising therapeutic modality for various nervous-system disorders; however, poor survival and differentiation of the transplanted NSCs limit their therapeutic efficacy. This study elucidated the effect of additive rehabilitative therapy with enriched environment (EE) and of achaete-scute homolog 1 (Mash1) and neurogenin2 (Ngn2) transduction on the fate of NSCs (P28-P35) transplanted into the primary somatosensory cortex (PSC) of mice. NSCs transplanted into the PSC differentiated into neurons and astrocytes and exhibited typical excitatory and synaptic response in mice housed in standard cages or in the EE.

Role of neuropsin in formation and maturation of Schaffer-collateral L1cam-immunoreactive synaptic boutons.

We report that neuropsin is involved in the synaptogenesis/maturation of orphan and small synaptic boutons in the Schaffer-collateral pathway. Most non-synaptic orphan boutons and a number of immature small synaptic boutons expressed the cell adhesion molecule L1 in presynaptic Schaffer-collateral terminals, whereas mature large boutons on mushroom spines were devoid of L1. The number of L1-immunoreactive boutons was markedly higher in neuropsin-deficient mice than in wild-type mice, whereas there were far fewer mature large boutons.

Distribution of L1cam mRNA in the adult mouse brain: In situ hybridization and Northern blot analyses.

Previous immunohistochemical analysis revealed a wide distribution of L1cam-positive neural and nonneural structures in adult mouse brain. Although there were numerous punctate immunoreactive nerve terminals, only a few immunoreactive neuronal cell somata were present (Munakata et al. [2003] BMC Neurosci.