PubMed Health⌕ Search

Biomedical subjects

Pierre Clement

Publications and source records attributed to Pierre Clement.

2 recordsLinked to original sources
PubMed2005

Nitric oxide and sleep.

Nitric oxide (NO) is a biological messenger synthesized by three main isoforms of NO synthase (NOS): neuronal (nNOS, constitutive calcium dependent), endothelial (eNOS, constitutive, calcium dependent) and inducible (iNOS, calcium independent). NOS is distributed in the brain either in circumscribed neuronal sets or in sparse interneurons. Within the laterodorsal tegmentum (LDT), pedunculopontine tegmentum and dorsal raphe nucleus, NOS-containing neurons overlap neurons grouped according to their contribution to sleep mechanisms. The main target for NO is the soluble guanylate cyclase that triggers an overproduction of cyclic guanosine monophosphate. NO in neurons of the pontine tegmentum facilitates sleep (particularly rapid-eye-movement sleep), and NO contained within the LDT intervenes in modulating the discharge of the neurons through an auto-inhibitory process involving the co-synthesized neurotransmitters. Moreover, NO synthesized within cholinergic neurons of the basal forebrain, while under control of the LDT, may modulate the spectral components of the EEG instead of the amounts of different sleep states. Finally, impairment of NO production (e.g. neurodegeneration, iNOS induction) has identifiable effects, including ageing, neuropathologies and parasitaemia.

Brain↗
PubMed2005

Neuroanatomy and physiology of ejaculation.

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 different peripheral anatomical structures (accessory sexual glands, ducti, and striated muscles) involved in ejaculation. The efferent pathways innervating these anatomical structures drive motor outputs originating from spinal thoracolumbar and lumbosacral nuclei. These spinal ejaculatory centers, the synchronized activation of which is likely carried out by a group of spinal cells, are under the control of both peripheral sensory afferents coming from genital areas and supraspinal information arising from specific brain regions.

Autonomic Nervous System↗