ISSN:
1432-0878
Keywords:
HRP injection
;
Lymnaea Stagnalis
;
Neurohaemal areas
;
Neurosecretory cell
;
Ultrastructure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The paired, electrotonically coupled neurosecretory Canopy Cells (CC) of the pond snail Lymnaea stagnalis were microiontophoretically injected with horseradish peroxidase (HRP). Whole mount preparations and ultrathin sections of injected CC were studied to describe in detail the morphology of the CC, their axon tracts and neurohaemal areas. The CC release their secretory product at three different sites, viz. from the soma and from axon terminals in the intercerebral commissure and in the median lip nerve. Neural control over the CC occurs by few synapses found exclusively on the CC axon, not on the cell body. One type of “en passant” synapse was identified. Two morphologically distinct types of synapselike structures (SLS) are numerous. The site of electrotonic coupling between the two CC is most probably located in the cerebral commissure. Serial sectioning showed that the axons contact each other over more than 130 μm. The contact is very intimate and the axon membranes interdigitate in a complex manner. Gap junctions, which are often described as the sites of electrotonic coupling, were not found.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00233656
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