No abstract

Epidermal growth factor (EGF) receptor (ErbB1) signals regulate dopaminergic development and function and are implicated in schizophrenia. We evaluated genetic effects on neurobehavioral changes induced by neonatal EGF administration, using four mouse strains. Subcutaneous EGF administration increased phosphorylation of brain ErbB1 in all strains, although DBA/2 and C57BL/6 mice had lower basal phosphorylation. Neonatal EGF treatment differentially influenced physical and behavioral/cognitive development, depending on mouse strain. Prepulse inhibition was decreased in DBA/2 and C57BL/6 mice but not C3H/He and ddY mice. Locomotor activity was accelerated in DBA/2 mice, but reduced in ddY mice. EGF treatment enhanced fear-learning performance with a tone cue in DBA/2 mice, but decreased performance with tone and context cues in C3H/He and ddY mice, respectively. The strain-dependent behavioral sensitivity was correlated with basal ErbB1 phosphorylation. Genetic components regulating brain ErbB1 signaling strongly influence the direction and strength of behavioral responses stemming from the neonatal neurotrophic perturbation.

No abstract

We report the growth of dilute nitride GaNAs and GaInNAs core-multishell nanowires by plasma-assisted molecular beam epitaxy. Using constituent Ga-induced vapor-liquid-solid growth, these nanowires were grown on Si(111) and silicon on insulator (SOI) substrates. The GaNAs shell nominally contains 0%, 2%, and 3% nitrogen. We also report the growth of GaAs/GaInNAs/GaAs core-multishell nanowires nominally containing 30% In and 2% N. Axial cross-sectional scanning transmission electron microscopy measurements and energydispersive X-ray spectrometry confirm the formation of the core-multishell nanowire structure. We obtained high-quality GaNAs nanowires with nitrogen compositions up to 2%. On the other hand, GaNAs containing 3% nitrogen, and GaInNAs nanowires, show distorted structure; moreover, the optical emissions seem to be related to defects. Further optimisations of the growth conditions will improve these properties, promising future applications in nanoscale optoelectronics.

We propose native oxide AlGaOx outer protective layer for GaAs/AlGaAs coremultishell nanowires to provide yearly stable stronger optical and electrical confinement within the nanowire core. We prepared core-multishell NWs consisting of GaAs core, Al0.2Ga0.8As multi-layered barrier layer, and amorphous Al0.9Ga0.1Ox outer shell, which was obtained simply by growing Al-rich AlGaAs and exposing the NWs to the ambient air. Photoluminescence from the NWs reveals that the Al0.9Ga0.1Ox outer shell provides efficient optical confinement and creates a compressive strain in the interior of the NW that enhances and blueshifts the photoluminescence of the GaAs core.