Pierre Clément

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Changes in sleep-wake states and nitric oxide release were examined in aged rats versus young-adult ones. Sleep-wake recordings and nitric oxide measurements were taken from animals chronically equipped with polygraphic and voltametric electrodes. Animals were examined in baseline conditions and in response to a 24-hour paradoxical sleep deprivation. In(More)
In this review, original observations on rotifer cilia and muscles are used to explain the mechanism of their movements. The following topics are discussed: (1) cilia and infraciliature of the cingulum, (2) muscle insertions into the infraciliature, (3) innervation of the muscles and non-innervation of the ciliated cells, (4) recent data on the location of(More)
INTRODUCTION Premature ejaculation (PE), whose pathophysiology is still not clearly identified, is the most common male sexual dysfunction, yet it remains underdiagnosed and undertreated. The aims of this paper are to provide a scientific and pharmacologic rationale, and to discuss to what extent selective serotonin reuptake inhibitors (SSRIs) can help(More)
INTRODUCTION Dopamine (DA) plays a key role in different aspects of the male sexual response, including sexual motivation and arousal, penile erection, and ejaculation. The modalities of action of DA are however unclear, although the various DA receptors may differentially mediate the activity of DA in different aspects of the male sexual response. AIM To(More)
The skeletal muscles of rotifers are monocellular or occasionally bicellular. They display great diversity of cytological features correlated to their functional differentiation. The cross-striated fibers of some retractors are fast contracting and relaxing, with A-band lengths of 0.7 µm to 1.6 µm, abundant sarcoplasmic reticulum and dyads. Other retractors(More)
Ejaculation is the final stage of coitus in the mammalian male and results in the expulsion of sperm out of the urethral meatus. Two successive phases, emission and expulsion, can be distinguished during ejaculatory response. Normal anterograde ejaculation requires close coordination of sympathetic, parasympathetic, and somatic components commanding the(More)
BACKGROUND AND PURPOSE The involvement of the neuropeptide oxytocin in the control of male sexual responses is documented although its exact mechanisms of action, and especially the site(s) of action, are not fully delineated. In order to clarify this issue, we tested the effects of a peptide oxytocin antagonist delivered through different routes on sexual(More)
The dynamics of bacterial populations in annual sea ice were measured throughout the vernal bloom of ice algae near Resolute in the Canadian Arctic. The maximum concentration of bacteria was 6.0·1011 cells·m−2 (about 2.0·1010 cells·l−1) and average cell volume was 0.473 μm3 in the lower 4 cm of the ice sheet. On average, 37% of the bacteria were epiphytic(More)
The first chapter summarizes the state of the disagreements about the phylogeny of rotifers and lower metazoa in 1963. The only arguments were morphological, and the only problem was the definition of homologies. There are today more diversified approaches of the evolution: electron microscopy, ethology, genetics and ecology. The second chapter shows, using(More)
1. Cette revue présente l'état actuel de nos connaissances sur les comportements des Rotifères. II s'agit soit de réponses immédiates, reflexes, a des stimulus, soit de séquences codées dont le déclenchement et la succession sont a base sensorielle: comportement alimentaire, reproducteur, ou qui suit la ponte chez N. copeus ... La perception de stimulations(More)