Chloroquine Affects Presynaptic Membrane Retrieval in Diaphragm Neuromuscular Junctions of Old Mice.

Aging disrupts multiple homeostatic processes, including autophagy, a cellular process for the recycling and degradation of defective cytoplasmic structures. Acute treatment with the autophagy inhibitor chloroquine blunts the maximal forces generated by the diaphragm muscle, but the mechanisms underlying neuromuscular dysfunction in old age remain poorly understood. We hypothesized that chloroquine treatment increases the presynaptic retention of the styryl dye FM 4-64 following high-frequency nerve stimulation, consistent with the accumulation of unprocessed bulk endosomes.

Search for Soft Unclustered Energy Patterns in Proton-Proton Collisions at 13 TeV.

The first search for soft unclustered energy patterns (SUEPs) is performed using an integrated luminosity of 138  fb^{-1} of proton-proton collision data at sqrt[s]=13  TeV, collected in 2016-2018 by the CMS detector at the LHC. Such SUEPs are predicted by hidden valley models with a new, confining force with a large 't Hooft coupling. In events with boosted topologies, selected by high-threshold hadronic triggers, the multiplicity and sphericity of clustered tracks are used to reject the background from standard model quantum chromodynamics.

Inhibition of TrkB kinase activity impairs autophagy in cervical motor neurons of young but not old mice.

Ageing-related neuromuscular dysfunction is associated with reduced tropomyosin-related kinase receptor subtype B (TrkB) signalling and accumulation of damaged cytoplasmic aggregates in motor neurons. Autophagy functions to remove these damaged aggregates, and we previously reported increased cervical motor neuron expression of LC3 and p62 in old age. We hypothesized that inhibition of TrkB kinase activity results in an increase in the relative expression of both LC3 and p62 in cervical motor neurons, consistent with impaired progression of autophagy.

Hypercapnia impacts neural drive and timing of diaphragm neuromotor control.

The neuromotor control of the diaphragm muscle (DIAm) involves motor unit recruitment, sustained activity (incrementing and decrementing), and motor unit derecruitment, phases that may be modified to maintain ventilation across conditions. The primary goal of the present study was to investigate the effects of hypercapnia, which increases respiratory rate and tidal volume, on DIAm neuromotor control in awake rats. We recorded DIAm electromyography (EMG) with implanted chronic fine-wire electrodes in nine Sprague-Dawley rats during normocapnia and hypercapnia (7% CO).