title: Olfactory projection neuron pathways in two species of marine Isopoda (Peracarida, Malacostraca, Crustacea).
abstract: The neuroanatomy of the olfactory pathway has been intensely studied in many representatives of Malacostraca. Nevertheless, the knowledge about bilateral olfactory integration pathways is mainly based on Decapoda. Here, we investigated the olfactory projection neuron pathway of two marine isopod species, Saduria entomon and Idotea emarginata, by lipophilic dye injections into the olfactory neuropil. We show that both arms of the olfactory globular tract form a chiasm in the center of the brain, as known from several other crustaceans. Furthermore, the olfactory projection neurons innervate both the medulla terminalis and the hemiellipsoid body of the ipsi- and the contralateral hemisphere. Both protocerebral neuropils are innervated to a comparable extent. This is reminiscent of the situation in the basal decapod taxon Dendrobranchiata. Thus, we propose that an innervation by the olfactory globular tract of both the medulla terminalis and the hemiellipsoid body is characteristic of the decapod ground pattern, but also of the ground pattern of Caridoida.
authors: Division of Cell Biology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors: Torben
authors: T
authors: Stemme
authors: Division of Cell Biology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors: René
authors: R
authors: Eickhoff
authors: Division of Cell Biology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany. Electronic address: gerd.bicker@tiho-hannover.de.
authors: Gerd
authors: G
authors: Bicker
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000648:ultrastructure*; D001921:Brain / Q000648:ultrastructure; D017952:Ganglia, Invertebrate / Q000648:ultrastructure*; D033321:Isopoda / Q000648:ultrastructure; D009474:Neurons / Q000648:ultrastructure*; D009833:Olfactory Pathways / Q000648:ultrastructure*
keywords: Evolution; Hemiellipsoid body; Lateral protocerebrum; Medulla terminalis; Olfactory globular tract; Olfactory neuropil