Reelin regulates the migration of late-born hippocampal CA1 neurons via cofilin phosphorylation

Regulatory mechanism of Reelin activity: a platform for exploiting Reelin as a therapeutic agent

Reelin is a secreted glycoprotein that was initially investigated in the field of neuronal development. However, in recent decades, its role in the adult brain has become increasingly important, and it is now clear that diminished Reelin function is involved in the pathogenesis and progression of neuropsychiatric and neurodegenerative disorders, including schizophrenia and Alzheimer's disease (AD). Reelin activity is regulated at multiple steps, including synthesis, posttranslational modification, secretion, oligomerization, proteolytic processing, and interactions with extracellular molecules. Moreover, the differential use of two canonical receptors and the presence of non-canonical receptors and co-receptors add to the functional diversity of Reelin. In this review, I summarize recent findings on the molecular mechanisms of Reelin activity. I also discuss possible strategies to enhance Reelin's function. A complete understanding of Reelin function and its regulatory mechanisms in the adult central nervous system could help ameliorate neuropsychiatric and neurodegenerative disorders.

Herbal Formula Extract Ameliorates Anxiety and Cognitive Impairment via Regulation of the Reelin/Dab-1 Pathway in a Murine Model of Post-Traumatic Stress Disorder

We investigated the effects of epigenetic modifications on post-traumatic stress disorder (PTSD) using a novel combination of herbal medicines from Panax ginseng, Astragalus membranaceus, Atractylodes macrocephala, and Glycyrrhiza uralensis. The herbal formula extract (HFE) (250 mg/kg) was administered orally once daily for 14 days to determine its effects on PTSD in mice by combining prolonged stress and foot shock. The open field and Y-maze tests determined the effect of HFE on PTSD-induced anxiety and cognition. Hippocampal neuronal plastic changes and molecular mechanism were verified. Treatment with HFE decreased anxiety-like behavior and enhanced cognition. Moreover, it reduced the number of PTSD-related hilar ectopic granule cells in the dentate gyrus (DG). PTSD mice showed reduced neuronal plasticity of doublecortin+ cells in the DG, which was restored by HFE treatment. HFE reversed PTSD-induced inhibition of the Reelin/Dab1 pathway, a critical signaling cascade involved in brain development, and regulated Reelin methylation. Furthermore, DNA methylation, methyl-CpG binding protein 2, and DNA methyltransferase 1, which were elevated in the hippocampus of PTSD mice, were restored following HFE treatment. HFE increased the expression of synaptic plasticity-related factors in the hippocampus of PTSD mice. Our findings suggest that HFE can facilitate PTSD treatment by alleviating behavioral abnormalities through the restoration of hippocampal dysfunction via regulation of the Reelin/Dab-1 pathway and DNA methylation in the hippocampus.

The Plasma Membrane Polarity Is Higher in the Neuronal Growth Cone than in the Cell Body of Hippocampal and Cerebellar Granule Neurons

The polarity of the biological membrane, or lipid order, regulates many cellular events. It is generally believed that the plasma membrane polarity is regulated according to cell type and function, sometimes even within a cell. Neurons have a variety of functionally specialized subregions, each of which bears distinct proteins and lipids, and the membrane polarity of the subregions may differ accordingly. However, no direct experimental evidence of it has been presented to date. In the present study, we used a cell-impermeable solvatochromic membrane probe NR12A to investigate the local polarity of the plasma membrane of neurons. Both in hippocampal and cerebellar granule neurons, growth cones have higher membrane polarity than the cell body. In addition, the overall variation in the polarity value of each pixel was greater in the growth cone than in cell bodies, suggesting that the lateral diffusion and/or dynamics of the growth cone membrane are greater than other parts of the neuron. These tendencies were much less notably observed in the lamellipodia of a non-neuronal cell. Our results suggest that the membrane polarity of neuronal growth cones is unique and this characteristic may be important for its structure and function.