Neural coordination of bilateral hand movements: evidence for an involvement of brainstem motor centres
J Physiol. 2024 Jan 4. doi: 10.1113/JP285403. Online ahead of print.ABSTRACTBilateral hand movements are assumed to be coordinated by a neural coupling mechanism. Neural coupling is experimentally reflected in complex electromyographic (EMG) responses in the forearm muscles of both sides to unilateral electrical arm nerve stimulation (ES). The aim of this study was to examine a potential involvement of the reticulospinal system in neural coupling by the application of loud acoustic stimuli (LAS) known to activate neurons of this system. LAS, ES and combined LAS/ES were applied to healthy subjects during visually guided bil...
Source: The Journal of Physiology - January 5, 2024 Category: Physiology Authors: Volker Dietz Nicole Sarah Holliger Andrin Christen Marina Geissmann Linard Filli Source Type: research
Intense exercise at high altitude causes platelet loss across the brain in humans
We examined platelet concentration across the brain in exercising humans at sea level (340 m) and high altitude (6-8 days at 3800 m; a stimulus known to modify platelet function). During intense exercise at sea level, platelet concentration increased similarly by 27 ± 17% in the arterial and internal jugular venous circulations (exercise: P < 0.001, interaction: P = 0.262), indicating no uptake or release of platelets into/from the brain. At high altitude, resting platelet concentrations were similar to sea level values in both the arterial and jugular venous circulations (P = 0.590); however, intense exercise at high ...
Source: The Journal of Physiology - January 5, 2024 Category: Physiology Authors: Travis Dylan Gibbons Hannah G Caldwell Hashim Islam Jennifer Duffy David B MacLeod Philip N Ainslie Source Type: research
Identifying peristaltic pacemaker cells in the upper urinary tract
J Physiol. 2024 Jan 5. doi: 10.1113/JP284754. Online ahead of print.ABSTRACTUrine expulsion from the upper urinary tract is a necessary process that eliminates waste, promotes renal filtration and prevents nephron damage. To facilitate the movement of urine boluses throughout the upper urinary tract, smooth muscle cells that line the renal pelvis contract in a coordinated effort to form peristaltic waves. Resident pacemaker cells in the renal pelvis are critical to this process and spontaneously evoke transient depolarizations that initiate each peristaltic wave and establish rhythmic contractions. Renal pacemakers have be...
Source: The Journal of Physiology - January 5, 2024 Category: Physiology Authors: Nathan Grainger Source Type: research
Mutation protocols share with sexual reproduction the physiological role of producing genetic variation within 'constraints that deconstrain'
J Physiol. 2024 Jan 4. doi: 10.1113/JP285478. Online ahead of print.ABSTRACTBecause the universe of possible DNA sequences is inconceivably vast, organisms have evolved mechanisms for exploring DNA sequence space while substantially reducing the hazard that would otherwise accrue to any process of random, accidental mutation. One such mechanism is meiotic recombination. Although sexual reproduction imposes a seemingly paradoxical 50% cost to fitness, sex evidently prevails because this cost is outweighed by the advantage of equipping offspring with genetic variation to accommodate environmental vicissitudes. The potential ...
Source: The Journal of Physiology - January 5, 2024 Category: Physiology Authors: David G King Source Type: research
Neural coordination of bilateral hand movements: evidence for an involvement of brainstem motor centres
J Physiol. 2024 Jan 4. doi: 10.1113/JP285403. Online ahead of print.ABSTRACTBilateral hand movements are assumed to be coordinated by a neural coupling mechanism. Neural coupling is experimentally reflected in complex electromyographic (EMG) responses in the forearm muscles of both sides to unilateral electrical arm nerve stimulation (ES). The aim of this study was to examine a potential involvement of the reticulospinal system in neural coupling by the application of loud acoustic stimuli (LAS) known to activate neurons of this system. LAS, ES and combined LAS/ES were applied to healthy subjects during visually guided bil...
Source: The Journal of Physiology - January 5, 2024 Category: Physiology Authors: Volker Dietz Nicole Sarah Holliger Andrin Christen Marina Geissmann Linard Filli Source Type: research
