Abstract

Research will be continued on the in vitro crab sinus gland neurosecretory system. The biophysical bases of electrical responses recorded intracellularly from the peptide neurohormone secreting terminals will be studied, and changes of electrical responses resulting from all other manipulations to be employed monitored. Fine-structural changes in terminals will also be monitored in parallel electron-microscope studies. Stimulus-secretion coupling is to be studied with improved time resolution to correlate intracellular changes during repetitive stimulation with 'facilitation' of erythrophore concentrating hormone (ECH) release. The rapid, semi-quantitative crab leg segment assay, sensitive to 5 times 10 to the minus 12th power molar synthetic ECH, will be used to determine ECH released into the perfusate. Involvement of metabolically dependent processes in acute release and in subsequent replenishment of hormone in terminals will be examined. Organ culture of the sinus gland system will be undertaken for studies employing isotopically labelled ECH precursor amino acids. Selective application of amino acids or drugs to somata or terminals is possible and will be exploited to localize processes involved in replenishment of hormone released from the terminals. The localization and time course of isotope distribution will be followed, not only by counting of perfusate collected during stimulation, but also by autoradiography of whole mounts, and of light and electron microscope sections. Experiments will test the effect on replenishment processes of secretory activity and seek the mechanism by which stimulation of these processes occurs. Electron-microscope examination of the terminals marked with Procion rubine injected through the intracellular recording electrode will permit correlation of electrophysiological characteristics of individual terminals with the type of neurosecretory granules each contains. Identification of the terminal type releasing ECH will be attempted.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS015453-07
Application #
3396267
Study Section
(SSS)
Project Start
1979-07-01
Project End
1989-04-30
Budget Start
1987-05-01
Budget End
1988-04-30
Support Year
7
Fiscal Year
1987
Total Cost
Indirect Cost

  Institution

Name
University of Hawaii
Department
Type
Organized Research Units
DUNS #
121911077
City
Honolulu
State
HI
Country
United States
Zip Code
96822

  Publications

Duan, S; Cooke, I M (2000) Glutamate and GABA activate different receptors and Cl(-) conductances in crab peptide-secretory neurons. J Neurophysiol 83:31-7
Duan, S; Cooke, I M (1999) Selective inhibition of transient K+ current by La3+ in crab peptide-secretory neurons. J Neurophysiol 81:1848-55
Meyers, D E; Cooke, I M (1997) Comparison of Ca2+ currents of peptidergic neurons developing differing morphology with time in culture. J Exp Biol 200:723-33
Richmond, J E; Penner, R; Keller, R et al. (1996) Characterization of the Ca2+ current in isolated terminals of crustacean peptidergic neurons. J Exp Biol 199:2053-9
Richmond, J E; Codignola, A; Cooke, I M et al. (1996) Calcium- and barium-dependent exocytosis from the rat insulinoma cell line RINm5F assayed using membrane capacitance measurements and serotonin release. Pflugers Arch 432:258-69
Sher, E; Codignola, A; Rogers, M et al. (1996) Noradrenaline inhibition of Ca2+ channels and secretion in single patch-clamped insulinoma cells. FEBS Lett 385:176-80
Richmond, J E; Sher, E; Keller, R et al. (1995) Regulation of calcium currents and secretion by magnesium in crustacean peptidergic neurons. Invert Neurosci 1:215-21
Richmond, J E; Sher, E; Cooke, I M (1995) Characterization of the Ca2+ current in freshly dissociated crustacean peptidergic neuronal somata. J Neurophysiol 73:2357-68
Keller, R; Grau, S; Cooke, I M (1995) Quantitation of peptide hormone in single cultured secretory neurons of the crab, Cardisoma carnifex. Cell Tissue Res 281:525-32
Graf, R A; Cooke, I M (1994) Outgrowth morphology and intracellular calcium of crustacean neurons displaying distinct morphologies in primary culture. J Neurobiol 25:1558-69

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