Health & Environmental Research Online (HERO)


Print Feedback Export to File
3087642 
Journal Article 
Ultrastructure of the stomatogastric ganglion neuropil of the crab, Cancer borealis 
Kilman, VL; Marder, E 
1996 
Yes 
Journal of Comparative Neurology
ISSN: 0021-9967
EISSN: 1096-9861 
374 
3 
362-375 
English 
8906505 
The stomatogastric ganglion (STG) of the crab, Cancer borealis, contains the neural networks responsible for rhythmic pattern generation of the foregut. Neuron counts indicate that the STG of C. borealis has 25-26 neurons, 4-5 fewer than that found in lobsters. We describe the ultrastructural features of the ganglion by focusing on those that may be involved in storage, release, or range of action of peptide modulators, including a lacunar system and multiple types of intercellular junctions. In the neuropil, we identify five synaptic profile classes that contain the invertebrate presynaptic apparatus (dense bars, small clear vesicles), two of which also contain dense core (modulator-containing) vesicles. These latter two are comprised of multiple immunocytochemical classes that are not easily distinguished by structural criteria. In addition, we find neurohemal-like profiles that contain primarily dense core vesicles. Our finding that multiple profile types in the STG possess modulator-containing vesicles coincides with immunocytochemical results better than do previous ultrastructural studies that report only one such profile type. We show that a single modulatory input, stomatogastric nerve axon 1, makes only classical synapses and not neurohemal-like profiles, although some modulators are found in both these profile types. These data provide the groundwork for understanding the architecture of modulatory input-target interactions and suggest ways that the specificity of modulatory effects within a complex neuropil may be attained.