While they play important roles in cerebellar function and high-frequency hearing and appear to serve structural functions at synapses, ligand-gated ion channel function has not been observed. However, we have previously shown that GluD2 can form functional ion channels when grafted with the ligand binding domain of a kainate receptor. In this study, we characterized this chimera as
well as additional rat delta receptor chimeras and point mutants in more detail. We found that the kainate receptor ligand binding domain renders GluD1 functional as well, and GluD2 becomes a functional ion channel also when provided with an AMPA receptor ligand binding domain. Point mutations indicate that the GluD2 ion pore operates similarly but not identically to that of AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic Selleck PD0325901 acid) and kainate receptors. GluD2 mutated at a conserved arginine within the linker region connecting the ligand binding domain to the ion pore domain displays spontaneous currents that occur in the absence of agonists and are inhibited by agonist application – a behavior reminiscent of that of the previously characterized lurcher mutant. Using our chimeric approach, we provide evidence that this inhibition of spontaneous currents by agonists may be caused Cabozantinib research buy by desensitization. Our results show that delta receptors have functional gating machineries and ion permeation pathways similar but not identical
to those of AMPA and kainate receptors, while the key differences seem to be located within the ligand binding domain. “
“The unique role of the EEG alpha rhythm in different states of cortical activity is still debated. The main theories regarding alpha function posit either sensory processing or attention allocation as the main processes governing its modulation. Closing and opening eyes, a well-known manipulation of the alpha rhythm, could be regarded as attention allocation from inward to outward focus though during light is also accompanied by visual change. To disentangle the effects of attention allocation and
sensory visual input on alpha modulation, 14 healthy subjects were asked to open and close their eyes during conditions of Celecoxib light and of complete darkness while simultaneous recordings of EEG and fMRI were acquired. Thus, during complete darkness the eyes-open condition is not related to visual input but only to attention allocation, allowing direct examination of its role in alpha modulation. A data-driven ridge regression classifier was applied to the EEG data in order to ascertain the contribution of the alpha rhythm to eyes-open/eyes-closed inference in both lighting conditions. Classifier results revealed significant alpha contribution during both light and dark conditions, suggesting that alpha rhythm modulation is closely linked to the change in the direction of attention regardless of the presence of visual sensory input.