Dopamine-beta-hydroxylase-like immunoreactive neurons in two insect species, Calliphora erythrocephala and Periplaneta americana.

The localization of dopamine-beta-hydroxylase in the cephalic central nervous system of the blowfly (Calliphora erythrocephala) and the cockroach (Periplaneta americana) was investigated. Immunoreactive neurons were demonstrated in both species. The results were compared with the known distribution of catecholamines in the brain of both species. In certain cell groups and neuropilar regions of both species D beta H-immunoreactivity coincides with the presence of catecholamines. Additionally D beta H immunoreactivity was found in several cell bodies and neuropilar regions in which no catecholamines could be detected. A correlation between the presence of octopamine and anti-D beta H labelling was not found. Thus it seems that the D beta H-immunoreactivity neither indicates the presence of octopamine nor is it limited to noradrenaline-containing neurons. Parallel findings in vertebrates are discussed.