TY - JOUR
T1 - Neurogenesis of cephalic sensory organs of Aplysia californica.
AU - Wollesen, Tim
AU - Wanninger, Andreas
AU - Klussmann-Kolb, Annette
N1 - Keywords: Afferent Pathways; Animals; Aplysia; Cell Differentiation; Epithelial Cells; FMRFamide; Ganglia, Invertebrate; Immunohistochemistry; Microscopy, Confocal; Microscopy, Electron, Scanning; Nervous System; Neurons, Afferent; Peripheral Nerves; Serotonin
PY - 2007
Y1 - 2007
N2 - The opisthobranch gastropod Aplysia californica serves as a model organism in experimental neurobiology because of its simple and well-known nervous system. However, its nervous periphery has been less intensely studied. We have reconstructed the ontogeny of the cephalic sensory organs (labial tentacles, rhinophores, and lip) of planktonic, metamorphic, and juvenile developmental stages. FMRFamide and serotonergic expression patterns have been examined by immunocytochemistry in conjunction with epifluorescence and confocal laser scanning microscopy. We have also applied scanning electron microscopy to analyze the ciliary distribution of these sensory epithelia. Labial tentacles and the lip develop during metamorphosis, whereas rhinophores appear significantly later, in stage 10 juveniles. Our study has revealed immunoreactivity against FMRFamides and serotonin in all major nerves. The common labial nerve develops first, followed by the labial tentacle base nerve, oral nerve, and rhinophoral nerve. We have also identified previously undescribed neuronal pathways and other FMRFamide-like-immunoreactive neuronal elements, such as peripheral ganglia and glomerulus-like structures, and two groups of conspicuous transient FMRFamide-like cell somata. We have further found two distinct populations of FMRFamide-positive cell somata located both subepidermally and in the inner regions of the cephalic sensory organs in juveniles. The latter population partly consists of sensory cells, suggesting an involvement of FMRFamide-like peptides in the modulation of peripheral sensory processes. This study is the first concerning the neurogenesis of cephalic sensory organs in A. californica and may serve as a basis for future studies of neuronal elements in gastropod molluscs.
AB - The opisthobranch gastropod Aplysia californica serves as a model organism in experimental neurobiology because of its simple and well-known nervous system. However, its nervous periphery has been less intensely studied. We have reconstructed the ontogeny of the cephalic sensory organs (labial tentacles, rhinophores, and lip) of planktonic, metamorphic, and juvenile developmental stages. FMRFamide and serotonergic expression patterns have been examined by immunocytochemistry in conjunction with epifluorescence and confocal laser scanning microscopy. We have also applied scanning electron microscopy to analyze the ciliary distribution of these sensory epithelia. Labial tentacles and the lip develop during metamorphosis, whereas rhinophores appear significantly later, in stage 10 juveniles. Our study has revealed immunoreactivity against FMRFamides and serotonin in all major nerves. The common labial nerve develops first, followed by the labial tentacle base nerve, oral nerve, and rhinophoral nerve. We have also identified previously undescribed neuronal pathways and other FMRFamide-like-immunoreactive neuronal elements, such as peripheral ganglia and glomerulus-like structures, and two groups of conspicuous transient FMRFamide-like cell somata. We have further found two distinct populations of FMRFamide-positive cell somata located both subepidermally and in the inner regions of the cephalic sensory organs in juveniles. The latter population partly consists of sensory cells, suggesting an involvement of FMRFamide-like peptides in the modulation of peripheral sensory processes. This study is the first concerning the neurogenesis of cephalic sensory organs in A. californica and may serve as a basis for future studies of neuronal elements in gastropod molluscs.
U2 - 10.1007/s00441-007-0460-0
DO - 10.1007/s00441-007-0460-0
M3 - Journal article
C2 - 17710438
SN - 0302-766X
VL - 330
SP - 361
EP - 379
JO - Cell and Tissue Research
JF - Cell and Tissue Research
IS - 2
ER -