The Study On The Antennal Nerves Pathway And The3D Reconstruction Of Antennal Lobe Glomeruli In Gryllus Bimaculatus

Objective:Investigate the projective morphology and distribution of endings of antennal receptor afferent nerve fibers in cerebral ganglion in Gryllus bimaculatus, and the shape, size, number and position of antennal lobe glomeruli. Reveal the neural structure and function of the primary olfactory pathway of Gryllus bimaculatus. Provide principle on tissue anatomical structure for olfactory learning and memory of insect.Methods:(1) The nickel chloride neuronal tracing technique was used to mark afferent nerve fibers of antennal receptor in Gryllus Bimaculatus. The regularity on morphology and distribution of antennal afferent nerve terminals in the brain was observed.(2) The3D structure of antennal lobe glomeruli in Gryllus bimaculatus was reconstructed after paraffin, silver stain, organization structure observation by microscopy and the computer3D reconstruction. The shape, size, number and position of antennal lobe glomeruli were determined.Results:The antennal afferent nerves in30crickets were marked. And we get22whole morphological clear visual specimens. Each specimen was observed by microscopic and drawn. The results showed that plenty of nerve endings of antennal receptor afferent nerve fibers, projecting into deutocerebrum in Gryllus Bimaculatus, terminated in the ipsilateral antennal lobe and the ipsilateral antennal mechanosensory and motor center, a part of fibers projected into protocerebrum extending forward, also, a part of fibers projected into the suboesophageal ganglion extending downward through the ipsilateral nerve cord;11specimens of brain in Gryllus bimaculatus were reconstructed the three-dimensional using Amira5.4.0software base on Windows7operating system environment.52glomeruli were identified through the computer3D reconstruction. There were six glomeruli in the anteroventral of antennal lobe, six glomeruli in the anterolateral of antennal lobe, four glomeruli in the anterocenter of antennal lobe, three glomeruli in the anteromedial of antennal lobe, six glomeruli in the anterodorsal of antennal lobe, six glomeruli in the centeromedial of antennal lobe, six glomeruli in the posteroventral of antennal lobe, five glomeruli in the posterolateral of antennal lobe, three glomeruli in the posteromedial of antennal lobe, three glomeruli in the posterocenter of antennal lobe and four glomeruli in theposterodorsal of antennal lobe. Each glomeruli was named according to its position.Conclusion: Most of antennal afferent nerve fibers projected into the antennal lobeand the antennal mechanosensory and motor center, a few antennal afferent nervefibers projected into the protocerebrum and the suboesophageal ganglion. The modeof multiple projections may play an important role on the olfactory informationintegration, antennal movement adjusting, taste and feeding activity. There were52glomeruli in the antennal lobe in Gryllus bimaculatus according to the results ofthree-dimensional reconstruction.