Neuromorphic computing aims to emulate the computing processes of the brain by replicating the functions of biological neural networks using electronic counterparts. One promising approach is dendritic computing, which takes inspiration from the multi-dendritic branch structure of neurons to enhance the processing capability of artificial neural networks. While there has been a recent surge of interest in implementing dendritic computing using emerging devices, achieving artificial dendrites with throughputs and energy efficiency comparable to those of the human brain has proven challenging. In this study, we report on the development of a compact and low-power neurotransistor based on a vertical dual-gate electrolyte-gated transistor (EGT) with short-term memory characteristics, a 30 nm channel length, a record-low read power of ~3.16 fW and a biology-comparable read energy of ~30 fJ. Leveraging this neurotransistor, we demonstrate dendrite integration as well as digital and analog dendritic computing for coincidence detection. We also showcase the potential of neurotransistors in realizing advanced brain-like functions by developing a hardware neural network and demonstrating bio-inspired sound localization. Our results suggest that the neurotransistor-based approach may pave the way for next-generation neuromorphic computing with energy efficiency on par with those of the brain.
Abstract In Southeast Asia, emerging subduction zones often appear to begin at the corners of small oceanic basins, which have a triangular‐indenter continent–ocean boundary geometry. To investigate the influence of a triangular corner on subduction initiation, we performed a series of three‐dimensional numerical simulations with varying corner angles and base lengths. The results show that the apex of the corner constitutes the initial location of subduction, irrespective of the angle or the extent of the corner. Smaller angle corners are more likely to facilitate subduction initiation. At the same time, wide acute angle corners are difficult to form. Our findings suggest that triangular corner structures may facilitate subduction initiation in smaller basins; however, the role such corners in subduction initiation is limited in larger basins. Our results emphasize the importance of accounting for the three‐dimensional geometry of a subduction zone when examining its subduction dynamics and geological features.
The voltage- and Ca2+-activated, large conductance K+ channel (BK, maxi-K) is expressed in the collecting duct system of kidney where it underlies flow- and Ca2+-dependent K+ excretion. To determine if other Ca2+-activated K+ channels (KCa) may participate in this process, mouse kidney and the K+-secreting mouse cortical collecting duct (CCD) cell line, mCCDcl1, were assessed for TRPV4 and KCa channel expression and cross-talk. qPCR mRNA analysis and immunocytochemical staining demonstrated TRPV4 and KCa expression in mCCDcl1 cells and kidney connecting tubule (CNT) and CCD. Three subfamilies of KCa channels were revealed: the high Ca2+-binding affinity small-conductance SK channels, SK1and SK3, the intermediate conductance channel, IK1, and the low Ca2+-binding affinity, BK channel (BKα subunit). Apparent expression levels varied in CNT/CCD where analysis of CCD principal cells (PC) and intercalated cells (IC) demonstrated differential staining: SK1:PCIC, IK1:PC>IC, BKα:PC = IC, and TRPV4:PC>IC. Patch clamp analysis and fluorescence Ca2+ imaging of mCCDcl1 cells demonstrated potent TRPV4-mediated Ca2+ entry and strong functional cross-talk between TRPV4 and KCa channels. TRPV4-mediated Ca2+ influx activated each KCa channel, as evidenced by selective inhibition of KCa channels, with each active KCa channel enhancing Ca2+ entry (due to membrane hyperpolarization). Transepithelial electrical resistance (TEER) analysis of confluent mCCDcl1 cells grown on permeable supports further demonstrated this cross-talk where TRPV4 activation induce a decrease in TEER which was partially restored upon selective inhibition of each KCa channel. It is concluded that SK1/SK3 and IK1 are highly expressed along with BKα in CNT and CCD and are closely coupled to TRPV4 activation as observed in mCCDcl1 cells. The data support a model in CNT/CCD segments where strong cross talk between TRPV4-mediated Ca2+ influx and each KCa channel leads to enhance Ca2+ entry which will support activation of the low Ca2+-binding affinity BK channel to promote BK-mediated K+ secretion.
Abstract One question in lymphocyte homing is how integrins are rapidly activated to enable immediate arrest of fast rolling lymphocytes upon encountering chemokines at target vascular beds given the slow chemokine-induced integrin inside-out activation. Herein we demonstrate that chemokine CCL25-triggered Ca 2+ influx induces T cell membrane-proximal external Ca 2+ concentration ([Ca 2+ ] ex ) drop in 6 s from physiological concentration 1.2 mM to 0.3 mM, a critical extracellular Ca 2+ threshold for inducing αLβ2 activation, triggering rapid αLβ2 activation and T cell arrest before occurrence of αLβ2 inside-out activation. Talin knockdown inhibits the slow inside-out activation of αLβ2 but not [Ca 2+ ] ex drop-triggered αLβ2 quick activation. Blocking Ca 2+ influx significantly suppresses T cell rolling-to-arrest transition and homing to skin lesions in a mouse psoriasis model, thus alleviating skin inflammation. [Ca 2+ ] ex decrease-triggered rapid integrin activation bridges the gap between initial chemokine stimulation and slow integrin inside-out activation, ensuring immediate lymphocyte arrest and subsequent diapedesis on the right location.