《in bag cell neurons of Aplysia》.pdfVIP

Proc. Natl. Acad. Sci. USA Vol. 80, pp. 5753-5757, September 1983 Neurobiology Primary structure and neuronal effects of a-bag cell peptide, a second candidate neurotransmitter encoded by a single gene in bag cell neurons of Aplysia (high pressure liquid chromatography/autotransmitter/egg-laying behavior/co-transmitter/long-term inhibition) BARRY S. ROTHMAN*, EARL MAYERI*t, RICHARD 0. BROWN*, PAU-MIAU YUANt, AND JOHN E. SHIVELY: *Deparment of Physiology, School of Medicine, University of California, San Francisco, California 94143; tDepartment of Basic Sciences, California College of Podiatric Medicine, San Francisco, California 94115; and tDepartment of Immunology, City of Hope Research Institute, Duarte, California 91010 Communicated by Eric R. Kandel, May 13, 1983 ABSTRACT A discharge of impulse activity in a group of neu- neurons, cells L2-L4, L6, which are normally inhibited by bag roendocrine cells, the bag cells, produces several types of pro- cell discharge (10, 11). This indicates that ELH does not di- longed responses in various identified neurons of the abdominal rectly or indirectly inhibit these cells and suggests that there ganglion of Aplysia. Two excitatory responses are almost certainly is a second neurotransmitter that mediates bag cell-induced in- mediated by egg-laying hormone, but this peptide cannot account hibition (10-12). Recent molecular genetic analysis shows that for other responses, such as inhibition of left upper quadrant neu- a bag cell-specific gene encodes a precursor protein that con- rons. We report here the isolation from bag cell clusters of three tains the sequences of ELH and several other potential cleav- structurally similar peptides, seven, eight, and nine residues long, age products (13, 14). We report here the characterization of that are candidate transmitters for mediating bag