Gastrin-cholecystokinin-like and neuroparsin-like immunoreactivities in the brain and retrocerebral neuroendocrine complex of the cockroach Blattella germanica.

Using single and double labelling techniques respectively, brain-corpora cardiaca-corpora allata complexes of the cockroach Blattella germanica have been immunohistochemically investigated with antisera raised against either the vertebrate peptide gastrin-cholecystokinin (CCK-8(s] and/or the locust neurohormone neuroparsin (NPA). Single immunolabelling with anti-CCK-8(s) reveals immunoreactive perikarya and processes in median and lateral parts of protocerebrum, optic lobes, deutocerebrum and tritocerebrum. Some fibres originating in median and lateral protocerebrum are intrinsic to the brain, whereas others terminate in the nervous areas of the corpora cardiaca. Single immunolabelling with anti-NPA reveals immunoreactive cell bodies in the median part of the protocerebrum and their processes terminate both in the nervous area of the corpora cardiaca and between the intrinsic secretory cells of this neurohaemal organ. Double immunolabelling with anti-CCK-8(s) and anti-NPA enables a description of the anatomical relations between the processes and the endings of these two neurosecretory systems.