Abstract
The issue of whether interactions between central neurons and the targets they innervate are involved in establishing segment-specific phenotypic differences in the central nervous system was evaluated by studying the effect of naturally occurring ectopic targets on individual identified neurons of the leech Hirudo medicinalis. The specimens studied were found to have additional sex organs located in segments adjacent to those containing the normal structures. We report our observations on neuronal morphology, the presence or absence of specific neurons, and total ganglionic cell number and discuss some of the possible ways in which the observed changes might have arisen.
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- COGGESHALL R. E., FAWCETT D. W. THE FINE STRUCTURE OF THE CENTRAL NERVOUS SYSTEM OF THE LEECH, HIRUDO MEDICINALIS. J Neurophysiol. 1964 Mar;27:229–289. doi: 10.1152/jn.1964.27.2.229. [DOI] [PubMed] [Google Scholar]
- Fernandez J. Structure of the leech nerve cord: distribution of neurons and organization of fiber pathways. J Comp Neurol. 1978 Jul 1;180(1):165–191. doi: 10.1002/cne.901800110. [DOI] [PubMed] [Google Scholar]
- Fernández J., Stent G. S. Embryonic development of the hirudinid leech Hirudo medicinalis: structure, development and segmentation of the germinal plate. J Embryol Exp Morphol. 1982 Dec;72:71–96. [PubMed] [Google Scholar]
- GRAY E. G., GUILLERY R. W. AN ELECTRON MICROSCOPICAL STUDY OF THE VENTRAL NERVE CORD OF THE LEECH. Z Zellforsch Mikrosk Anat. 1963 Sep 18;60:826–849. doi: 10.1007/BF00339095. [DOI] [PubMed] [Google Scholar]
- Johansen J., Hockfield S., McKay R. D. Distribution and morphology of nociceptive cells in the CNS of three species of leeches. J Comp Neurol. 1984 Jun 20;226(2):263–273. doi: 10.1002/cne.902260210. [DOI] [PubMed] [Google Scholar]
- Kramer A. P., Weisblat D. A. Developmental neural kinship groups in the leech. J Neurosci. 1985 Feb;5(2):388–407. doi: 10.1523/JNEUROSCI.05-02-00388.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lewis E. B. A gene complex controlling segmentation in Drosophila. Nature. 1978 Dec 7;276(5688):565–570. doi: 10.1038/276565a0. [DOI] [PubMed] [Google Scholar]
- Macagno E. R. Number and distribution of neurons in leech segmental ganglia. J Comp Neurol. 1980 Mar 15;190(2):283–302. doi: 10.1002/cne.901900206. [DOI] [PubMed] [Google Scholar]
- Macagno E. R., Stewart R. R., Zipser B. The expression of antigens by embryonic neurons and glia in segmental ganglia of the leech Haemopis marmorata. J Neurosci. 1983 Sep;3(9):1746–1759. doi: 10.1523/JNEUROSCI.03-09-01746.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nicholls J. G., Baylor D. A. Specific modalities and receptive fields of sensory neurons in CNS of the leech. J Neurophysiol. 1968 Sep;31(5):740–756. doi: 10.1152/jn.1968.31.5.740. [DOI] [PubMed] [Google Scholar]
- Shafer M. R., Calabrese R. L. Similarities and differences in the structure of segmentally homologous neurons that control the hearts of the leech, Hirudo medicinalis. Cell Tissue Res. 1981;214(1):137–153. doi: 10.1007/BF00235152. [DOI] [PubMed] [Google Scholar]
- Weisblat D. A., Harper G., Stent G. S., Sawyer R. T. Embryonic cell lineages in the nervous system of the glossiphoniid leech Helobdella triserialis. Dev Biol. 1980 Apr;76(1):58–78. doi: 10.1016/0012-1606(80)90362-0. [DOI] [PubMed] [Google Scholar]
- Weisblat D. A., Kim S. Y., Stent G. S. Embryonic origins of cells in the leech Helobdella triserialis. Dev Biol. 1984 Jul;104(1):65–85. doi: 10.1016/0012-1606(84)90037-x. [DOI] [PubMed] [Google Scholar]
- Zipser B. Complete distribution patterns of neurons with characteristic antigens in the leech central nervous system. J Neurosci. 1982 Oct;2(10):1453–1464. doi: 10.1523/JNEUROSCI.02-10-01453.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]