Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The development of substance P-like immunoreactivity (SPLI) was studied in the Xenopus embryonic nervous system in order to determine in which neuronal populations and at what developmental times SPLI is expressed. Although Rohon-Beard neurons initially were thought to be the only substance P-immunoreactive cells in the embryonic frog spinal cord, we have demonstrated that several neuronal phenotypes are immunoreactive. The earliest evidence of SPLI was seen at stage 28 (Nieuwkoop and Faber, '67), at which time only some trigeminal ganglion cells, their axons in the ophthalmic nerve, and axons in the lateral tracts of the hindbrain showed SPLI. In the embryonic brain at stages 29/30, 37/38, and 42, SPLI was seen in the hypothalamus, trigeminal ganglion cells and their peripheral axons, the sensory roots of cranial nerve IX/X, and axons in the hindbrain lateral tracts. At premetamorphic stages, SPLI was found in several populations that are immunoreactive in adult amphibia. In the embryonic spinal cord, Rohon-Beard neurons were labeled consistently with reaction product; there was a rostrocaudal time gradient of immunoreactivity with increasing development. The Rohon-Beard neurons were not immunoreactive at developmental stages in which axonal outgrowth was beginning (stage 21), but were strongly immunoreactive at stages in which target cells had been contacted (stage 29). Several types of interneurons in the spinal cord (as classified by Roberts and Clarke, '82) showed SPLI during embryonic stages. At premetamorphic stages the Rohon-Beard neurons began to disappear and the immunoreactive interneurons were distributed similarly to those reported in the adult. Dorsal root ganglia differentiated during these stages, and at this time some of the neurons belonging to these ganglia exhibited substance P-like immunoreactivity.
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PMID:Development of substance P-like immunoreactivity in Xenopus embryos. 244 Sep 13

Rohon-Beard neurones show substance P-like immunoactivity in their somas and in their centrally projecting axons. Peripherally, the morphology of their free nerve endings within the trunk skin has been shown using horseradish peroxidase staining. The excitation of Rohon-Beard neurones by natural and electrical stimulation of the skin has been examined using intracellular micro-electrodes in the late embryo of Xenopus laevis. Rohon-Beard cells are sensitive to transient, local indentation of the trunk skin, responding with one or a few impulses. They adapt rapidly to repeated stimulation. They can also be excited by a brief current pulse to the skin. They are not sensitive to slow indentation of the skin, nor are they excited by epithelial action potentials. The responses to skin stimulation are not abolished by a Ringer solution containing 12 mM-Mg2+ and only 0.5 mM-Ca2+. Intracellularly evoked action potentials in single Rohon-Beard cells are sometimes sufficient to evoke sustained episodes of fictive swimming. The results indicate that Rohon-Beard cells are responsible for detecting light touch stimuli to the embryo's body and for initiating swimming in response to this stimulus.
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PMID:Sensory physiology, anatomy and immunohistochemistry of Rohon-Beard neurones in embryos of Xenopus laevis. 620 12