Search Results (7)

The current opinion paper puts into perspective how altered microbiota transplanted from Alzheimer’s patients initiates the impairment of the microbiota–gut–brain axis of a healthy recipient, leading to impaired cognition primarily arising from the hippocampus, dysfunctional adult hippocampal neurogenesis, dysregulated systemic inflammation, long-term spatial memory impairment, or chronic pain with hippocampal involvement. This altered microbiota may induce acquired Piezo2 channelopathy on enterochromaffin cells, which, in turn, impairs the ultrafast long-range proton-based oscillatory synchronization to the hippocampus. Therefore, an intact microbiota–gut–brain axis could be responsible for the synchronization of ultradian and circadian rhythms, with the assistance of rhythmic bacteria within microbiota, to circadian regulation, and hippocampal learning and memory formation. Hippocampal ultradian clock encoding is proposed to be through a Piezo2-initiated proton-signaled manner via VGLUT3 allosteric transmission at a distance. Furthermore, this paper posits that these unaccounted-for ultrafast proton-based long-range oscillatory synchronizing ultradian axes may exist not only within the brain but also between the periphery and the brain in an analogous way, like in the case of this depicted microbiota–gut–brain axis. Accordingly, the irreversible Piezo2 channelopathy-induced loss of the Piezo2-initiated ultradian prefrontal–hippocampal axis leads to Alzheimer’s disease pathophysiology onset. Moreover, the same irreversible microdamage-induced loss of the Piezo2-initiated ultradian muscle spindle–hippocampal and cerebellum–hippocampal axes may lead to amyotrophic lateral sclerosis and Parkinson’s disease initiation, respectively. Full article

Unaccustomed and/or strenuous eccentric contractions are known to cause delayed-onset muscle soreness. In spite of this fact, their exact cause and mechanism have been unknown for more than 120 years. The exploration of the diverse functionality of the Piezo2 ion channel, as the principal proprioceptive component, and its autonomously acquired channelopathy may bring light to this apparently simple but mysterious pain condition. Correspondingly, the neurocentric non-contact acute compression axonopathy theory of delayed-onset muscle soreness suggests two damage phases affecting two muscle compartments, including the intrafusal (within the muscle spindle) and the extrafusal (outside the muscle spindle) ones. The secondary damage phase in the extrafusal muscle space is relatively well explored. However, the suggested primary damage phase within the muscle spindle is far from being entirely known. The current manuscript describes how the proposed autonomously acquired Piezo2 channelopathy-induced primary damage could be the initiating transient neural switch in the unfolding of delayed-onset muscle soreness. This primary damage results in a transient proprioceptive neural switch and in a switch from quantum mechanical free energy-stimulated ultrafast proton-coupled signaling to rapid glutamate-based signaling along the muscle–brain axis. In addition, it induces a transient metabolic switch or, even more importantly, an energy generation switch in Type Ia proprioceptive terminals that eventually leads to a transient glutaminolysis deficit and mitochondrial deficiency, not to mention a force generation switch. In summary, the primary damage or switch is likely an inward unidirectional proton pathway reversal between Piezo2 and its auxiliary ligands, leading to acquired Piezo2 channelopathy. Full article

The current opinion manuscript posits that not only Piezo2 voltage block, but also proton affinity and availability in relation to Piezo2, a mechanically gated ion channel, may count in the mediation of pain and its sensitivity. Moreover, this paper argues that autonomously acquired Piezo2 channelopathy on somatosensory terminals is likely the initiating peripheral impaired input source that drives the central sensitization of spinal nociceptive neurons on the chronic path as being the autonomous pain generator. In parallel, impaired proprioception and the resultant progressive deficit in neuromuscular junctions of motoneurons might be initiated on the chronic path by the impairment of the proton-based ultrafast proprioceptive feedback to motoneurons due to disconnection through vesicular glutamate transporter 1. The irreversible form of this autonomously acquired Piezo2 ion channel microdamage, in association with genetic predisposition and/or environmental risk factors, is suggested to lead to progressive motoneuron death in addition to loss of pain sensation in amyotrophic lateral sclerosis. Furthermore, the impairment of the proton-based ultrafast long-range oscillatory synchronization to the hippocampus through vesicular glutamate transporter 2 may gain further importance in pain modulation and formation on the chronic path. Overall, this novel, unaccounted Piezo2-initiated protonic extrafast signaling, including both the protonic ultrafast proprioceptive and the rapid nociceptive ones, within the nervous system seems to be essential in order to maintain life. Hence, its microdamage promotes neurodegeneration and accelerates aging, while the complete loss of it is incompatible with life sustainment, as is proposed in amyotrophic lateral sclerosis. Full article

Amyotrophic lateral sclerosis (ALS) is a mysterious lethal multisystem neurodegenerative disease that gradually leads to the progressive loss of motor neurons. A recent non-contact dying-back injury mechanism theory for ALS proposed that the primary damage is an acquired irreversible intrafusal proprioceptive terminal Piezo2 channelopathy with underlying genetic and environmental risk factors. Underpinning this is the theory that excessively prolonged proprioceptive mechanotransduction under allostasis may induce dysfunctionality in mitochondria, leading to Piezo2 channelopathy. This microinjury is suggested to provide one gateway from physiology to pathophysiology. The chronic, but not irreversible, form of this Piezo2 channelopathy is implicated in many diseases with unknown etiology. Dry eye disease is one of them where replenishing synthetic proteoglycans promote nerve regeneration. Syndecans, especially syndecan-3, are proposed as the first critical link in this hierarchical ordered depletory pathomechanism as proton-collecting/distributing antennas; hence, they may play a role in ALS pathomechanism onset. Even more importantly, the shedding or charge-altering variants of Syndecan-3 may contribute to the Piezo2 channelopathy-induced disruption of the Piezo2-initiated proton-based ultrafast long-range signaling through VGLUT1 and VGLUT2. Thus, these alterations may not only cause disruption to ultrafast signaling to the hippocampus in conscious proprioception, but could disrupt the ultrafast proprioceptive signaling feedback to the motoneurons. Correspondingly, an inert Piezo2-initiated proton-based ultrafast signaled proprioceptive skeletal system is coming to light that is suggested to be progressively lost in ALS. In addition, the lost functional link of the MyoD family of inhibitor proteins, as auxiliary subunits of Piezo2, may not only contribute to the theorized acquired Piezo2 channelopathy, but may explain how these microinjured ion channels evolve to be principal transcription activators. Full article

Phytochromes are bistable red/far-red light-responsive photoreceptor proteins found in plants, fungi, and bacteria. Light-activation of the prototypical phytochrome Cph1 from the cyanobacterium Synechocystis sp. PCC 6803 allows photoisomerization of the bilin chromophore in the photosensory module and a subsequent series of intermediate states leading from the red absorbing Pr to the far-red-absorbing Pfr state. We show here via osmotic and hydrostatic pressure-based measurements that hydration of the photoreceptor modulates the photoconversion kinetics in a controlled manner. While small osmolytes like sucrose accelerate Pfr formation, large polymer osmolytes like PEG 4000 delay the formation of Pfr. Thus, we hypothesize that an influx of mobile water into the photosensory domain is necessary for proceeding to the Pfr state. We suggest that protein hydration changes are a molecular event that occurs during photoconversion to Pfr, in addition to light activation, ultrafast electric field changes, photoisomerization, proton release and uptake, and the major conformational change leading to signal transmission, or simultaneously with one of these events. Moreover, we discuss this finding in light of the use of Cph1-PGP as a hydration sensor, e.g., for the characterization of novel hydrogel biomaterials. Full article

The new proton timing stations of the Totem experiment are based on UltraFast Silicon Detectors installed in Roman Pots at 220 m from the interaction point 5 at LHC. The sensors have shown in beam test a timing resolution in the range 30–100 ps, depending on the pixel size. The readout is performed through a fast sampler chip: the SAMPIC. The best timing resolution can indeed be obtained only by recording the full waveform of the detector signal. The challenges to integrate the chip and the detector in the Totem-CMS DAQ and control systems will be discussed, together with the solutions adopted. The system has been successfully operated in LHC during some commissioning runs and during the special run in July 2018. Full article

Bacteriorhodopsin protein (bR)-based systems are one of the simplest known biological energy converters. The robust chemical, thermal and electrochemical properties of bR have made it an attractive material for photoelectric devices. This study demonstrates the photoelectric response of a dry bR layer deposited on a nitrocellulose membrane with indium tin oxide (ITO) electrodes. Light-induced electrical current as well as potential and impedance changes of dried bR film were recorded as the function of illumination. We have also tested bR in solution and found that the electrical properties are strongly dependent on light intensity changing locally proton concentration and thus pH of the solution. Experimental data support the assumption that bR protein on a positively charged nitrocellulose membrane (PNM) can be used as highly sensitive photo- and pH detector. Here the bR layer facilitates proton translocation and acts as an ultrafast optoelectric signal transducer. It is therefore useful in applications related to bioelectronics, biosensors, bio-optics devices and current carrying junction devices. Full article