Our findings suggested that BDNF contributed to neuronal growth and proliferation and differentiation of NSCs in vitro by stimulating PI3K/AKT/GSK3β/β-catenin pathways.

Brain-derived neurotrophic factor (BDNF) plays important roles in neural stem cell (NSC) growth. In this study, we investigated whether BDNF exerts its neurotrophic effects through the Wnt/β-catenin signaling pathway in human embryonic spinal cord NSCs (hESC-NSCs) in vitro. We found an increase in hESC-NSC growth by BDNF overexpression. Furthermore, expression of Wnt1, Frizzled1 and Dsh was upregulated, whereas GSK-3β expression was downregulated. In contrast, hESC-NSC growth was decreased by BDNF RNA interference. BDNF, Wnt1 and β-catenin components were all downregulated, whereas GSK-3β was upregulated. Next, we treated hESC-NSCs with 6-bromoindirubin-3'-oxime (BIO), a small molecule inhibitor of GSK-3β. BIO reduced the effects of BDNF upregulation/downregulation on the cell number, soma size and differentiation, and suppressed the effect of BDNF modulation on the Wnt signaling pathway. Our findings suggest that BDNF promotes hESC-NSC growth in vitro through crosstalk with the Wnt/β-catenin signaling pathway, and that this interaction may be mediated by GSK-3β.

Chronic alcohol exposure induced the region-specific expression of BDNF and proBDNF and their respective receptors in the brain. These results suggest that BDNF and proBDNF signaling pathways may play major roles in alcohol preference and addiction.

Interaction‐free measurement (IFM)‐based single‐photon interference is developed as a powerful platform for revealing object information in quantum metrology, where the presence of a sample is identified without photon “touching” in an interferometer. Herein, a method of obtaining the spectroscopic properties with interaction‐free quantum spectroscopy (IFQS) based on the spectrum‐correlated photon pairs by the spontaneous parametric down‐conversion (SPDC) is proposed and implemented. Infrared signal photons around 1557 nm from the SPDC pairs are sent to a Mach–Zehnder interferometer (MZI), which contains a semitransparent sample in one of the arms. The transmission spectrum of the sample is characterized by recording the coincidence detection of the spectrum‐correlated near‐infrared heralding photons around 808 nm from the SPDC. The IFQS can not only distinguish the existence of the sample but also recognize the sample by its transmission spectrum without interaction. The approach unlocks the potential to facilitate the applications of correlation‐based quantum spectroscopy and reduce the power‐induced optical damage of fragile materials.

In conclusion, these results demonstrate that NGR1 promotes growth of cultured cortical neurons from the neonatal rat, possibly via the Wnt/β-catenin signaling pathway.