Neuroscience
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Non-synaptic transmission is pervasive throughout the nervous system. It appears especially prevalent in peripheral ganglia, where non-synaptic interactions between neighboring cell bodies have been described in both physiological and pathological conditions, a phenomenon referred to as cross-depolarization (CD) and thought to play a role in sensory processing and chronic pain. CD has been proposed to be mediated by a chemical agent, but its identity has remained elusive. ⋯ Furthermore, we show that DRG glial cells also play a cell-type specific role in CD regulation. Fluorocitrate-induced glial inactivation had no effect on A-cells but enhanced CD in C-cells. These findings shed light on the mechanism of CD in the DRG and pave the way for further analysis of non-synaptic neuronal communication in sensory ganglia.
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Schwann cells (SCs) combined with acellular nerve allografts (ANAs) effectively promote the regeneration and repair of peripheral nerves, but the exact mechanism has not been fully elucidated. However, the disadvantages of SCs include their limited source and slow rate of expansion in vitro. Previous studies have found that adipose-derived stem cells have the ability to differentiate into Schwann-like cells. ⋯ The results showed that adipose-derived Schwann-like cells combined with ANAs markedly promoted sciatic nerve regeneration and repair. These findings also demonstrated that the expression of neurotrophic factors (NFs) was increased, and the expression of Janus activated kinase2 (JAK2)/P-JAK2, signal transducer and activator of transcription-3 (STAT3)/P-STAT3 was decreased in the spinal cord after SNI. Therefore, these results suggested that highly expressed NFs in the spinal cord could promote nerve regeneration and repair by inhibiting activation of the JAK2/STAT3 signaling pathway.
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Microglia activation plays a key role in regulating inflammatory and immune reaction during cerebral ischemia and it exerts pro-inflammatory or anti-inflammatory effect depending on M1/M2 polarization phenotype. Cysteinyl leukotriene 2 receptor (CysLT2R) is a potent inflammatory mediator receptor, and involved in cerebral ischemic injury, but the mechanism of CysLT2R regulating inflammation and neuron damage remains unclear. Here, we found that LPS and CysLT2R agonist NMLTC4 significantly increased microglia proliferation and phagocytosis, up-regulated the mRNA expression of M1 polarization markers (IL-1β, TNF-α, IFN-γ, CD86 and iNOS), down-regulated the expression of M2 polarization markers (Arg-1, CD206, TGF-β, IL-10, Ym-1) and increased the release of IL-1β and TNF-α. ⋯ The conditional medium of BV-2 cells contained HAMI3379 could inhibit SH-SY5Y cells apoptosis induced by LPS and NMLTC4. These results were further confirmed in primary microglia. The findings indicate that CysLT2R was involved in inflammation and neuronal damage by inducing the activation of microglia M1 polarization and NF-κB pathway, inhibiting microglia M1 polarization and promoting microglia polarization toward M2 phenotype which may exerts neuroprotective effects, and targeting CysLT2R may be a new therapeutic strategy against cerebral ischemia stroke.
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Although the neural basis underlying visuospatial reasoning has been widely explored by neuroimaging techniques, the brain activation patterns during naturalistic visuospatial reasoning such as tangram remains unclear. In this study, the directional functional connectivity of fronto-parietal networks during the tangram task was carefully inspected by using combined functional near-infrared spectroscopy (fNIRS) and conditional Granger causality analysis (GCA). Meanwhile, the causal networks during the traditional spatial reasoning task were also characterized to exhibit the differences with those during the tangram task. ⋯ Further correlation analyses showed that the behavioral performance in the spatial reasoning rather than the tangram task manifested the relationship with the connectivity between the frontal and parietal cortex. Our findings demonstrate that the tangram task measures a different aspect of the visuospatial reasoning ability which requires more trial-and-error strategies and creative thinking rather than inductive reasoning. In particular, the frontal cortex is mostly involved in tangram puzzle-solving, whereas the interaction between frontal and parietal cortices is regulated by the hands-on experience during the tangram task.