Serotonin-immunoreactive neurones in the visual system of the praying mantis: an immunohistochemical, confocal laser scanning and electron microscopic study.
The distribution, number, and morphology of serotonin-immunoreactive (5-HTi) neurones in the optic lobe of the praying mantis Tenodera sinensis were studied using conventional microscopy and confocal laser scanning microscopy. Five or six 5-HTi neurones connect the lobula complex with the medulla, and at least 50 5-HTi neurones appear to be confined to the medulla. In addition, a few large 5-HTi processes from the protocerebrum supply the lobula complex, and two large 5-HTi processes from the protocerebrum ramify in the medulla and lamina, where they show wide field arborisations. In order to provide a basis for understanding the action of serotonin in the lamina, the ultrastructure of its 5-HTi terminals was examined by conventional and immunohistochemical electron microscopy. The 5-HTi profiles were filled with dense core vesicles and made synapses. Output synapses from 5-HTi profiles outnumbered inputs by about 3 to 1. The terminals of the 5-HTi neurones were in close contact with cells of various types, including large monopolar cells, but close apposition to photoreceptor terminals was rare, and no synapses were found between 5-HTi terminals and photoreceptor terminals.
Leitinger
G
G
Institut für Histologie und Embryologie, Karl Franzens-Universität Graz, Harrachgasse 21, A-8010, Graz, Austria. gerd.leitinger@newcastle.ac.uk
Pabst
M A
MA
Kral
K
K
D000716:Anatomy, Artistic; D000818:Animals; D007150:Immunohistochemistry; D020050:Mantodea / Q000033:anatomy & histology / Q000502:physiology*; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D009474:Neurons / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D012701:Serotonin / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology* / Q000648:ultrastructure
D012701:Serotonin