These experiments combine immunological and electrophysiological techniques to investigate the regulation of neuroendocrine activity in the central nervous system of the marine mollusc Aplysia. The neuroendocrine bag cells synthesize a family of peptides which, when released, initiate a series of stereotypic behaviors leading to egg deposition. Although the bag cell system has been studied intensively for years, and has contributed substantially to the way we think about fundamental neuroendocrine processes, a crucial question has never been answered: what is the physiological stimulus that activates the normally quiescent bag cells? This proposal addresses that question. We take advantage of recent observations that the atrial gland, an exocrine organ in the reproductive tract, contains at least three peptides that can activate the bag cells. The receptive sites for these peptides will be mapped electrophysiologically by selective lesioning and application of peptides to specific regions of the central nervous system while recording from the bag cells and identified central nerrons. We will also develop monoclonal antibodies agains these structurally related peptides and use them to localize neuronal sources of peptides that could regulate bag cell activity. Finally, we will use electrophysiological techniques to characterize the functional connection between the cells that synthesize (and release) the regulatory peptides and the cells that respond to them.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS022079-02
Application #
3404023
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1985-04-01
Project End
1988-03-31
Budget Start
1986-04-01
Budget End
1987-03-31
Support Year
2
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Texas Medical Br Galveston
Department
Type
Schools of Medicine
DUNS #
041367053
City
Galveston
State
TX
Country
United States
Zip Code
77555
Nagle, G T; de Jong-Brink, M; Painter, S D et al. (1990) Delta-bag cell peptide from the egg-laying hormone precursor of Aplysia. Processing, primary structure, and biological activity. J Biol Chem 265:22329-35
de Jong-Brink, M; Nagle, G T; Dictus, W J et al. (1990) A calfluxin-related peptide is present in the bag cells and atrial gland of Aplysia. Gen Comp Endocrinol 79:114-22
Brass, L M; Duterte, D L; Mohr, J P (1989) Anterior cerebral artery velocity changes in disease of the middle cerebral artery stem. Stroke 20:1737-40
Nagle, G T; Knock, S L; Painter, S D et al. (1989) Aplysia californica neurons R3-R14: primary structure of the myoactive histidine-rich basic peptide and peptide I. Peptides 10:849-57
Nagle, G T; Painter, S D; Blankenship, J E (1989) Post-translational processing in model neuroendocrine systems: precursors and products that coordinate reproductive activity in Aplysia and Lymnaea. J Neurosci Res 23:359-70
Painter, S D; Kalman, V K; Nagle, G T et al. (1989) Localization of immunoreactive alpha-bag-cell peptide in the central nervous system of Aplysia. J Comp Neurol 287:515-30
Painter, S D; Gustavson, A R; Kalman, V K et al. (1989) Induction of copulatory behavior in Aplysia: atrial gland factors mimic the excitatory effects of freshly deposited egg cordons. Behav Neural Biol 51:222-36
Nagle, G T; Painter, S D; Blankenship, J E et al. (1988) The bag cell egg-laying hormones of Aplysia brasiliana and Aplysia californica are identical. Peptides 9:867-72
Nagle, G T; Painter, S D; Blankenship, J E et al. (1988) Proteolytic processing of egg-laying hormone-related precursors in Aplysia. Identification of peptide regions critical for biological activity. J Biol Chem 263:9223-37
Painter, S D; Rock, M K; Nagle, G T et al. (1988) Peptide B induction of bag-cell activity in Aplysia: localization of sites of action to the cerebral and pleural ganglia. J Neurobiol 19:695-706

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