Nervous system

About: Nervous system is a research topic. Over the lifetime, 16729 publications have been published within this topic receiving 847181 citations.

Tissue distribution and quantitation of the mRNAs for three rat tachykinin receptors

Abstract: The family of mammalian tachykinin receptors consists of substance P receptor (SPR), neuromedin K receptor (NKR) and substance K receptor (SKR). In this investigation, tissue and regional distributions of the mRNAs for the three rat tachykinin receptors were investigated by blot-hybridization and RNase-protection analyses using the previously cloned receptor cDNAs. SPR mRNA is widely distributed in both the nervous system and peripheral tissues and is expressed abundantly in the hypothalamus and olfactory bulb, as well as in the urinary bladder, salivary glands and small and large intestines. In contrast, NKR mRNA is predominantly expressed in the nervous system, particularly in the cortex, hypothalamus and cerebellum, whereas SKR mRNA expression is restricted to the peripheral tissues, being abundant in the urinary bladder, large intestine, stomach and adrenal gland. Thus, the mRNAs for the three tachykinin receptors show distinct patterns of expression between the nervous system and peripheral tissues. Blot-hybridization analysis in combination with S1 nuclease protection and primer-extension analyses revealed that there are two large forms of SKR mRNA expressed commonly in the peripheral tissues, and two additional small forms of the mRNA expressed specifically in the adrenal gland and eye. These analyses also showed that the multiple forms of SKR mRNA differ in the lengths of the 5' mRNA portions, and that the two small forms of the mRNA, if translated, encode a truncated SKR polypeptide lacking the first two transmembrane domains. This investigation thus provides the comprehensive analysis of the distribution and mode of expression of the mRNAs for the multiple peptide receptors and offers a new basis on which to interpret the diverse functions of multiple tachykinin peptides in the CNS and peripheral tissues.

Regulated expression of the neural cell adhesion molecule L1 by specific patterns of neural impulses

Abstract: Development of the mammalian nervous system is regulated by neural impulse activity, but the molecular mechanisms are not well understood. If cell recognition molecules [for example, L1 and the neural cell adhesion molecule (NCAM)] were influenced by specific patterns of impulse activity, cell-cell interactions controlling nervous system structure could be regulated by nervous system function at critical stages of development. Low-frequency electrical pulses delivered to mouse sensory neurons in culture (0.1 hertz for 5 days) down-regulated expression of L1 messenger RNA and protein (but not NCAM). Fasciculation of neurites, adhesion of neuroblastoma cells, and the number of Schwann cells on neurites was reduced after 0.1-hertz stimulation, but higher frequencies or stimulation after synaptogenesis were without effect.

S100 protein is present in cultured human malignant melanomas

Abstract: S100 protein, so called because of its solubility in 100% saturated ammonium sulphate1, is an acidic cytoplasmic protein specific for the nervous system2,3. It is localized primarily to glial elements of the brain, Schwann cells in the peripheral nervous system and satellite cells in sympathetic ganglia4,5. This brain-specific protein shows a close immunological relationship among a wide variety of vertebrates, as measured by a quantitative complement fixation technique6. Although strict serological conservation and tissue localization have been maintained among different species, no function for S100 protein has been determined. However, the appearance of S100 protein in brain is correlated with maturation of the nervous system in both rat and man7,8. Previous in vitro studies on the production and regulation of S100 protein in the C6 cell line derived from a rat astrocytoma indicated that cell contact and cessation of division induced S100 protein9. Neuroblastoma cell lines lack this protein10,11 although it is found in other astrocyte cell lines. We are unaware of any reports of cell lines, other than those of glial origin, which produce S100 protein. Melanocytes are derived from neuroectodermal elements, and this common origin of glial cells and melanocytes prompted us to study whether S100 protein might be present in cell lines from human malignant melanomas. We now report the presence of S100 protein in five of seven continuous cell lines of human malignant melanoma.

Synthesis by a clonal line of rat glial cells of a protein unique to the nervous system.

Abstract: The synthesis of a protein unique to the nervous system, the “S100-protein,” has been studied in a clonal line of rat glial cells. It has been shown that these cells do not begin to accumulate “S100-protein” until the cultures enter a phase of density-dependent inhibition of cell proliferation. Further experiments indicate that the regulation of “S100-protein” accumulation resides at least in part in an interaction involving the cell surface.