Monoamine-containing neurons and their projections in the brain (supraoesophageal ganglion) of cockroaches. AN aldehyde fluorescence study.

Fluorogenic monoamines were studied in the brain of three cockroach species by use of aldehyde-fluorescence techniques. All three optic ganglia contain fluorogenic monoamines. The lamina contains fibres with an indolylalkylamine-fluorophore. The medulla is innervated by local CA neurons which contribute to four fluorescent strata. The lobula receives both CA- and 5-HT-fibres, predominantly of central origin. CA occur in almost all areas of the brain. The areas are interconnected by a CA-fibre system. All parts of the mushroom body are innervated by CA-fibres from the surrounding neuropil. The CA innervation in the mushroom body divides it into a fronto-ventral part (alpha-lobe, beta-lobe, anterio-ventral peduncle) and a dorso-caudal part (caudo-dorsal peduncle, calices) leaving a fluorescence-free central part of the peduncle in between. CA-fibres run between the mushroom bodies of both hemispheres and also between the mushroom body and the lobula. The central body complex contains CA. The pons aggregates indolylalkylamine-containing fibres. The olfactory glomeruli are surrounded by CA-fibres originating from deutocerebral cell bodies. CA-fibres are further linked to the protocerebral neuropil. CA-fibre tracts pass from the brain to the suboesophageal ganglion and the stomatogastric nervous system. The cell bodies of the frontal ganglion are of indolylalkylamine type. Non-fluorescent neuropils (n. ocellaris, tractus olfactorio-globularis, lobus glomerulatus) are innervated by the CA-fibre system.