Fig. 3. Putative neurohaemal release zone on the surface of the circumoesophageal connective (coc) and the post-oesophageal commissure (poc). (A) Drawing of allatostatin-like immunoreactivity on the surface of the cocs and the poc found only in Cherax destructor. Similar staining was found with antibodies generated against crustacean cardioactive peptide and proctolin. Other stained structures, including axons in the coc and cell bodies and neuropile in the commissural ganglia (CoGs) were not drawn. ion, inferior oesophageal nerve; son, superior oesophageal nerve. (B) Transmission electron micrograph of a cross section through the poc showing a large profile in the perineural sheath that contains dense-core vesicles (arrowheads) and electron-dense granules (arrows) close to a glial cell (g) process. The profile is separated from the haemolymph space (h) only by a thin extracellular matrix (em) representing a basal lamina. m, mitochondrion. Scale bar, 0.5µm. A is modified from Skiebe, 1999; B is modified from Skiebe et al., 1999.