1
|
Lu JT, Son YJ, Lee J, Jetton TL, Shiota M, Moscoso L, Niswender KD, Loewy AD, Magnuson MA, Sanes JR, Emeson RB. Mice lacking alpha-calcitonin gene-related peptide exhibit normal cardiovascular regulation and neuromuscular development. Mol Cell Neurosci 1999; 14:99-120. [PMID: 10532808 DOI: 10.1006/mcne.1999.0767] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
alpha-Calcitonin gene-related peptide (alphaCGRP) is a pleiotropic peptide neuromodulator that is widely expressed throughout the Central and peripheral nervous systems. CGRP has been implicated in a variety of physiological processes including peripheral vasodilation, cardiac acceleration nicotinic acetylcholine receptor (AChR) synthesis and function, testicular descent, nociception, carbohydrate metabolism, gastrointestinal motility, neurogenic inflammation, and gastric acid secretion. To provide a better understanding of the physiological role(s) mediated by this peptide neurotransmitter, we have generated alphaCGRP-null mice by targeted modification in embryonic stem cells. Mice lacking alpha CGRP expression demonstrate no obvious phenotypic differences from their wild-type littermates. Detailed analysis of systemic cardiovascular function revealed no differences between control and mutant mice regarding heart rate and blood pressure under basal or exercise-induced conditions and subsequent to pharmacological manipulation. Characterization of neuromuscular junction in morphology including nicotinic receptor localization, terminal sprouting in response to denervation, developmental regulation of AChR subunit expression, and synapse elimination also revealed no differences in alphaCGRP-deficient animals. These results suggest that alphaCGRP is not required for the systemic regulation of cardiovascular hemodynamics or development of the neuromuscular junction.
Collapse
Affiliation(s)
- J T Lu
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
2
|
Abstract
During neuromuscular synapse formation, motor axons induce clustering of acetylcholine receptors (AChRs) in the muscle fiber membrane. The protein agrin, originally isolated from the basal lamina of the synaptic cleft, is synthesized and secreted by motoneurons and triggers formation of AChR clusters on cultured myotubes. We show here postsynaptic AChR aggregates are markedly reduced in number, size, and density in muscles of agrin-deficient mutant mice. These results support the hypothesis that agrin is a critical organizer of postsynaptic differentiation does occur in the mutant, suggesting the existence of a second-nerve-derived synaptic organizing signal. In addition, we show that intramuscular nerve branching and presynaptic differentiation are abnormal in the mutant, phenotypes which may reflect either a distinct effect of agrin or impaired retrograde signaling from a defective postsynaptic apparatus.
Collapse
Affiliation(s)
- M Gautam
- Department of Anatomy and Neurobiology, Washington University Medical School St. Louis, Missouri 63110, USA
| | | | | | | | | | | | | |
Collapse
|
3
|
Beaulieu JP, Lamers HJGLM, Grison P, Julien R, Lanciaux C, Ferlet R, Vidal-Madjar A, Bertin E, Maurice E, Prevot L, Gry C, Guibert J, Moreau O, Tajhmady F, Aubourg E, Bareyre P, Gros M, Laurent B, Lachieze-Rey M, Lesquoy E, Magneville C, Milsztajn A, Moscoso L, Queinnec F, Renault C, Rich J, Spiro M, Vigroux L, Zylberajch S, Ansari R, Cavalier F, Moniez M. Pre-Main-Sequence Star Candidates in the Bar of the Large Magellanic Cloud. Science 1996; 272:995-7. [PMID: 8662586 DOI: 10.1126/science.272.5264.995] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Candidate pre-main-sequence stars were observed in the bar of the Large Magellanic Cloud during the search for dark matter in the galactic halo. Seven blue stars of apparent visual magnitude 15 to 17 had irregular photometric variations and hydrogen emission lines in their optical spectra, which suggested that these stars are pre-main-sequence stars of about 10 solar masses. These stars are slightly more massive and definitely more luminous than are Herbig AeBe pre-main-sequence stars in our own galaxy. Continued observations of these very young stars from another galaxy, which are probably at the pre-hydrogen-burning stage, should provide important clues about early stages of star formation.
Collapse
Affiliation(s)
- JP Beaulieu
- The EROS (Experience de Recherche d'Objets Sombres) collaboration: J. P. Beaulieu, P. Grison, R. Julien, C. Lanciaux, R. Ferlet, A. Vidal-Madjar, Institut d'Astrophysique de Paris, 98bis Boulevard, Arago, 75014 Paris, France. H. J. G. L. M. Lamers, Astronomical Institute, Princetonplein 5, NL-3584 CC Utrecht, Netherlands, and SRON Laboratory for Space Research, Sorbonnelaan 2, NL-3584 CA Utrecht, Netherlands. E. Bertin, Institut d'Astrophysique de Paris, 98bis Boulevard, Arago, 75014 Paris, France, and ESO La Silla, casilla 19001, Santiago 19, Chile. E. Maurice and L. Prevot, Observatoire de Marseille, 2 place Le Verrier, 13248 Marseille 04, France. C. Gry, Laboratoire d'Astronomie Spatiale CNRS, Traversee du siphon, les trois lucs, 13120 Marseille, France. J. Guibert, O. Moreau, F. Tajhmady, Centre d'Analyse des Images de l'Institut National des Sciences de l'Univers, CNRS Observatoire de Paris, 61 Avenue de l'Observatoire, 75014 Paris, France. E. Aubourg, P. Bareyre, J. de Kat, M. Gros, B. Laurent, M. Lachieze-Rey, E. Lesquoy, C. Magneville, A. Milsztajn, L. Moscoso, F. Queinnec, C. Renault, J. Rich, M. Spiro, L. Vigroux, S. Zylberajch, CEA, DSM/DAPNIA, Centre d'etudes de Saclay, 91191 Gif-sur-Yvette, France. R. Ansari, F. Cavalier, M. Moniez, Laboratoire de l'Accelerateur Lineaire IN2P3, Centre d'Orsay, 91405 Orsay, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Berger C, Fr�hlich M, M�nch H, Nisius R, Raupach F, Schleper P, Benadjal Y, Blum D, Bourdarios C, Dudelzak B, Eschstruth P, Jullian S, Lalanne D, Laplanche F, Longuemare C, Paulot C, Perdereau O, Roy P, Szklarz G, Behr L, Degrange B, Nguyen-Khac U, Tisserant S, Arpesella C, Bareyre P, Barloutaud R, Borg A, Chardin G, Ernwein J, Glicenstein JF, Mosca L, Moscoso L, Becker J, Becker KH, Daum HJ, Jacobi B, Kuznik B, L�ffler J, Meyer H, M�ller R, Schubnell M, Wei Y, Wintgen P. Results from the Fr�jus experiment on nucleon decay modes with charged leptons. ACTA ACUST UNITED AC 1991. [DOI: 10.1007/bf01551450] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
5
|
Berger C, Fröhlich M, Mönch H, Nisius R, Raupach F, Schleper P, Benadjal Y, Blum D, Bourdarios C, Dudelzak B, Eschstruth P, Jullian S, Lalanne D, Laplanche F, Longuemare C, Paulot C, Perdereau O, Roy P, Szklarz G, Behr L, Degrange B, Minet Y, Nguyen-Khac U, Serri P, Tisserant S, Tripp RD, Arpesella C, Bareyre P, Barloutaud R, Borg A, Chardin G, Ernwein J, Glicenstein JF, Mosca L, Moscoso L, Becker J, Becker KH, Daum HJ, Demski S, Jacobi B, Kuznik B, Mayer R, Meyer H, Möller R, Schubnell M, Seyffert B, Wei Y, Wintgen P. Experimental study of muon bundles observed in the Fréjus detector. Phys Rev D Part Fields 1989; 40:2163-2171. [PMID: 10012055 DOI: 10.1103/physrevd.40.2163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|