The correlation of ULF waves and auroral intensity before, during and after substorm expansion phase onset

We present case studies of the evolution of magnetic wave amplitudes and auroral intensity through the late growth phase and the expansion phase of the substorm cycle. We present strong evidence that substorm-related auroral enhancements are clearly and demonstrably linked to ULF wave amplitudes observed at the same location. In most cases, we find that the highest correlations are observed when the magnetometer time series is advanced in time, indicating that the ULF wave amplitudes start to grow before measured auroral intensities, though interestingly this is not always the case. Further we discuss the four possible reasons that may be able to explain both the timing and the high correlations between these two phenomena, including: a simple coincidence, an artifact of instrumental effects, the response of the ionosphere to magnetic waves and auroral particle precipitation, and finally that ULF waves and auroral particle precipitation are physically linked. We discount coincidence and instrumental effects since in the studies presented here they are unlikely or in general will contribute negligible effects, and we find that the ionospheric response to waves and precipitation can explain some, but not all of the results contained within this paper. Specifically, ionospheric response to substorm waves and auroral precipitation cannot explain that the result that previous studies have shown, that onset of ULF wave activity and the onset of auroral particle precipitation occur at the same time and in the same location. This leaves the possibility that ULF waves and auroral particles are physically linked

The Mitochondria-Regulated Immune Pathway Activated in the C. elegans Intestine Is Neuroprotective

Immunological mediators that originate outside the nervous system can affect neuronal health. However, their roles in neurodegeneration remain largely unknown. Here, we show that the p38MAPK-mediated immune pathway activated in intestinal cells of Caenorhabditis elegans upon mitochondrial dysfunction protects neurons in a cell-non-autonomous fashion. Specifically, mitochondrial complex I dysfunction induced by rotenone activates the p38MAPK/CREB/ATF-7-dependent innate immune response pathway in intestinal cells of C. elegans. Activation of p38MAPK in the gut is neuroprotective. Enhancing the p38MAPK-mediated immune pathway in intestinal cells alone suppresses rotenone-induced dopaminergic neuron loss, while downregulating it in the intestine exacerbates neurodegeneration. The p38MAPK/ATF-7 immune pathway modulates autophagy and requires autophagy and the PTEN-induced putative kinase PINK-1 for conferring neuroprotection. Thus, mitochondrial damage induces the clearance of mitochondria by the immune pathway, protecting the organism from the toxic effects of mitochondrial dysfunction. We propose that mitochondria are subject to constant surveillance by innate immune mechanisms

Mesoscopic Neural Representations in Spatial Navigation

Recent evidence suggests that mesoscopic neural oscillations measured via intracranial electroencephalography exhibit spatial representations, which were previously only observed at the micro- and macroscopic level of brain organization. Specifically, theta (and gamma) oscillations correlate with movement, speed, distance, specific locations, and goal proximity to boundaries. In entorhinal cortex (EC), they exhibit hexadirectional modulation, which is putatively linked to grid cell activity. Understanding this mesoscopic neural code is crucial because information represented by oscillatory power and phase may complement the information content at other levels of brain organization. Mesoscopic neural oscillations help bridge the gap between single-neuron and macroscopic brain signals of spatial navigation and may provide a mechanistic basis for novel biomarkers and therapeutic targets to treat diseases causing spatial disorientation.</p