Track topics on Twitter Track topics that are important to you
Human sperm show a variety of different behaviours (types of motility) that have different functional roles. Previous reports suggest that sperm may reversibly switch between these behaviours. We have recorded and analysed the behaviour of individual human sperm (180 cells in total), each cell monitored continuously for 3-3.5 min either under control conditions or in the presence of Ca2+-mobilising stimuli. Switching between different behaviours was assessed visually (1 s bins using 4 behaviour categories), and was verified by fractal dimension analysis of sperm head tracks. In the absence of stimuli, approximately 90% of cells showed at least one behavioural transition (mean rate under control conditions = 6.4 ± 0.8 transitions.min-1). Type 1 behaviour (progressive, activated-like motility) was most common but the majority of cells (>70%) displayed at least three behaviour types. Treatment of sperm with Ca2+-mobilising agonists had negligible effects on the rate of switching but increased the time spent in type 2 and type 3 (hyperactivation-like) behaviours (P < 2*10-8; chi square). Treatment with 4-aminopyridine under alkaline conditions (pHo = 8.5), a highly-potent Ca2+-mobilising stimulus, was the most effective in increasing the proportion of type 3 behaviour, biasing switching away from type 1 (P < 0.005) and dramatically extending the duration of type 3 events (P < 10-16). Other stimuli, including 300 nM progesterone and 1% human follicular fluid, had qualitatively similar effects but were less potent. We conclude that human sperm observed in vitro constitutively display a range of behaviours and regulation of motility by [Ca2+]i, at the level of the single cell, is achieved not by causing cells to adopt a 'new' behaviour but by changing the relative contributions of those behaviours.
This article was published in the following journal.
Name: Molecular human reproduction
Metformin is a leading antidiabetic drug that is used worldwide in the treatment of diabetes mellitus. This biguanide exerts metabolic and pleiotropic effects in somatic cells, although its in vitro...
Photosensitizers (PSs) with stimuli responsive reversible switchable of intersystem crossing (ISC) is highly promising for smart photodynamic therapy (PDT), but achieving this goal remains a tremendou...
Motile flagella are crucial for human fertility and embryonic development. The distal tip of the flagellum is where growth and intra-flagellar transport are coordinated. In most, but not all, model or...
Task switching refers to the demanding cognitive control process that allows us to flexibly switch between different task contexts. It is a seminal observation that task switching comes with a perform...
Human spermatozoa can fertilize an oocyte only after post-testicular maturation and capacitation. These processes involve dynamic modification and reorganization of the sperm plasma membrane, which al...
This is a cross-sectional observational study aiming to examine and compare the impact of incretin based therapies i.e. dipeptidyl peptidase-4 (DPP4) inhibitors and glucagon-like peptide-1...
The purpose of this research project is to determine whether or not the directional movement of spermatozoa is influenced by a pH gradient by examining spermatozoa in vitro.
The study aims to investigate the effects of 3.0 mg of liraglutide on reward brain circuits in human obesity and to better understand its effects on weight loss (in patients without diabet...
The purpose of this study is to seek the presence of ZIKV in semen, to determine its localization and to assess the efficiency of spermatozoa processing methods to obtain virus free sperma...
Despite evidence of high rates of concurrent substance use and anger problems among problem gamblers, until recently there have been no empirically evaluated treatments for these co-morbid...
Gene rearrangement of the B-lymphocyte which results in a substitution in the type of heavy-chain constant region that is expressed. This allows the effector response to change while the antigen binding specificity (variable region) remains the same. The majority of class switching occurs by a DNA recombination event but it also can take place at the level of RNA processing.
Chemical substances which inhibit the process of spermatozoa formation at either the first stage, in which spermatogonia develop into spermatocytes and then into spermatids, or the second stage, in which spermatids transform into spermatozoa.
Specialized afferent neurons capable of transducing sensory stimuli into NERVE IMPULSES to be transmitted to the CENTRAL NERVOUS SYSTEM. Sometimes sensory receptors for external stimuli are called exteroceptors; for internal stimuli are called interoceptors and proprioceptors.
A genus of the family PICORNAVIRIDAE whose members preferentially inhabit the intestinal tract of a variety of hosts. The genus contains many species. Newly described members of human enteroviruses are assigned continuous numbers with the species designated "human enterovirus".
Continuous sequential changes which occur in the physiological and psychological functions during the life-time of an individual.