Search results for "nucleus"
showing 10 items of 1803 documents
Localization of parvalbumin, calretinin, and calbindin D-28k in identified extraocular motoneurons and internuclear neurons of the cat
1998
Calcium-binding proteins have been shown to be excellent markers of specific neuronal populations. We aimed to characterize the expression of calcium-binding proteins in identified populations of the cat extraocular motor nuclei by means of immunohistochemistry against parvalbumin, calretinin, and calbindin D-28k. Abducens, medial rectus, and trochlear motoneurons were retrogradely labeled with horseradish peroxidase from their corresponding muscles. Oculomotor and abducens internuclear neurons were retrogradely labeled after horseradish peroxidase injection into either the abducens or the oculomotor nucleus, respectively. Parvalbumin staining produced the highest density of immunoreactive …
Search for magnetically-induced signatures in the arrival directions of ultra-high-energy cosmic rays measured at the Pierre Auger Observatory
2020
We search for signals of magnetically-induced effects in the arrival directions of ultra-high-energy cosmic rays detected at the Pierre Auger Observatory. We apply two different methods. One is a search for sets of events that show a correlation between their arrival direction and the inverse of their energy, which would be expected if they come from the same point-like source, they have the same electric charge and their deflection is relatively small and coherent. We refer to these sets of events as "multiplets". The second method, called "thrust", is a principal axis analysis aimed to detect the elongated patterns in a region of interest. We study the sensitivity of both methods using a …
NuSTEC White Paper: Status and challenges of neutrino–nucleus scattering
2018
International audience; The precise measurement of neutrino properties is among the highest priorities in fundamental particle physics, involving many experiments worldwide. Since the experiments rely on the interactions of neutrinos with bound nucleons inside atomic nuclei, the planned advances in the scope and precision of these experiments require a commensurate effort in the understanding and modeling of the hadronic and nuclear physics of these interactions, which is incorporated as a nuclear model in neutrino event generators. This model is essential to every phase of experimental analyses and its theoretical uncertainties play an important role in interpreting every result.In this Wh…
Improved calculations of beta decay backgrounds to new physics in liquid xenon detectors
2020
We present high-precision theoretical predictions for the electron energy spectra for the ground-state to ground-state $\beta$ decays of $^{214}$Pb, $^{212}$Pb, and $^{85}$Kr most relevant to the background of liquid xenon dark matter detectors. The effects of nuclear structure on the spectral shapes are taken into account using large-scale shell model calculations. Final spectra also include atomic screening and exchange effects. The impact of nuclear structure effects on the $^{214}$Pb and $^{212}$Pb spectra below $\approx100$ keV, pertinent for several searches for new physics, are found to be comparatively larger than those from the atomic effects alone. We find that the full calculatio…
Electroweak processes in nucleons and nuclei at intermediate energies
2014
263 páginas. Tesis Doctoral del Departamento de Física Teórica de la Universidad de Valencia y del Instituto de Física Corpuscular (IFIC).
Topography of somatostatin gene expression relative to molecular progenitor domains during ontogeny of the mouse hypothalamus
2010
The hypothalamus comprises alar, basal, and floor plate developmental compartments. Recent molecular data support a rostrocaudal subdivision into rostral (terminal) and caudal (peduncular) halves. In this context, the distribution of neuronal populations expressing somatostatin (Sst) mRNA was analyzed in the developing mouse hypothalamus, comparing with the expression pattern of the genes Orthopedia (Otp), Distal-less 5 (Dlx5), Sonic Hedgehog (Shh), and Nk2 homeobox 1 (Nkx2.1). At embryonic day 10.5 (E10.5), Sst mRNA was first detectable in the anterobasal nucleus, a Nkx2.1-, Shh-, and Otp-positive basal domain. By E13.5, nascent Sst expression was also related to two additional Otp-positiv…
Nuclear calcium signaling by inositol trisphosphate in GH3 pituitary cells
2008
It has been proposed that nuclear and cytosolic Ca2+ ([Ca2+]N and [Ca2+]C) may be regulated independently. We address here the issue of whether inositol trisphosphate (IP3) can, bypassing changes of [Ca2+]C, produce direct release of Ca2+ into the nucleoplasm. We have used targeted aequorins to selectively measure and compare the changes in [Ca2+]C and [Ca2+]N induced by IP3 in GH3 pituitary cells. Heparin, an IP3 inhibitor that does not permeate the nuclear pores, abolished the [Ca2+]C peaks but inhibited only partly the [Ca2+]N peaks. The permeant inhibitor 2-aminoethoxy-diphenyl-borate (2-APB) blocked both responses. Removal of ATP also inhibited more strongly the [Ca2+]C than [Ca2+]N pe…
Heterogeneous responses of nucleus incertus neurons to corticotrophin-releasing factor and coherent activity with hippocampal theta rhythm in the rat
2013
The nucleus incertus (NI) of the rat hindbrain is a putative node in the ascending control of the septohippocampal system and hippocampal theta rhythm and is stress and arousal responsive. NI contains GABA neurons that express multiple neuropeptides, including relaxin-3 (RLN3) and neuropeptide receptors, including corticotrophin-releasing factor receptor-1 (CRF-R1), but the precise anatomical and physiological characteristics of NI neurons are unclear. Therefore, we examined the firing properties of NI neurons and their responses to CRF, the correlation of these responses with occurrence of relaxin-3, and NI neuron morphology in the rat. Most NI neurons excited by intracerebroventricular CR…
Extensive nuclear gyration and pervasive non-genic transcription during primordial germ cell development in zebrafish.
2020
ABSTRACT Primordial germ cells (PGCs) are the precursors of germ cells, which migrate to the genital ridge during early development. Relatively little is known about PGCs after their migration. We studied this post-migratory stage using microscopy and sequencing techniques, and found that many PGC-specific genes, including genes known to induce PGC fate in the mouse, are only activated several days after migration. At this same time point, PGC nuclei become extremely gyrated, displaying general broad opening of chromatin and high levels of intergenic transcription. This is accompanied by changes in nuage morphology, expression of large loci (PGC-expressed non-coding RNA loci, PERLs) that ar…
Unique clockwork in photoreceptor of rat
2010
In mammals, the retina contains a clock system that oscillates independently of the master clock in the suprachiasmatic nucleus and allows the retina to anticipate and to adapt to the sustained daily changes in ambient illumination. Using a combination of laser capture micro-dissection and quantitative PCR in the present study, the clockwork of mammalian photoreceptors has been recorded. The transcript amounts of the core clock genes Clock, Bmal1, Period1 (Per1), Per3, Cryptochrome2, and Casein kinase Ie in photoreceptors of rat retina have been found to undergo daily changes. Clock and Bmal1 peak with Per1 and Per3 around dark onset, whereas Casein kinase Ie and Cryptochrome2 peak at night…