Application Of 3D Printer To Print The Model Of Brain In Adult Helicoverpa Armigera(Hübner)

To make an insect brain model could provide a useful tool for the study on the structure and function of brain,as well as for the teaching in the field of insect science.In this study,we investigated the anatomical structure of the brain of adult Helicoverpa armigera and then printed a brain model.Immunohistochemical staining with synaptic protein antibody was used to label the neuropil structure of the brain.A confocal laser scanning microscope was used to obtain digital images of the brain.Then the digital images of brain were analyzed by using the image processing softwares,AMIRA5.3 and Adobe photoshop Elements 9.The anatomical structures of brain in adult H.armigera were identified and the three-dimentional models were reconstructed,and finally,the digital models were printed by using a 3D printer.The main results of this study were summarized as follows:(1)Based on the synapsin staining,the neuropils of the brain,such as the optic lobes,the mushroom bodies,the central complex,the anterior optic tubercles and the antennal lobes were identified and reconstructed.The volumes of these neuropils of the brain were measured and the relative sizes were calculated.In addition,the other neuropils of the brain,plus the subesophageal ganglion,was reconstructed and categorized as the midbrain.The optic lobes,the mushroom bodies,the anterior optic tubercles and the antennal lobes are paired structures located in both sides of brain.However,the central complex is an unpaired structure.(2)The brain and subesophageal ganglia of adult H.armigera are fused together,but with a hole in the middle,resulted from the passing of the esophagus.The brain is composed of protocerebrum,deutocerebrum,and tritocerebrum.The protocerebrum consists of the optic lobes,the mushroom bodies,the central complex and the anterior optic tubercles.The volume of protocerebrum is larger than that of deutocerebrum and tritocerebrum.The deutocerebrum mainly contains a pair of antennal lobes.The tritocerebrum is adjacent to subesophageal ganglia.No substructure was identified inthe tritocerebrum.(3)The digital three-dimensional model can be transferred into a 3D printer and printed with the material of PLA.The printed brain model is 15 cm long,5.3 cm wide,and 7.8 cm high.In addition,the optic lobes,the antennal lobes,the mushroom body lobes,the mushroom body calyx,the anterior optic tubercles,and the central body were printed with PLA in different colours.All these printed models of brain structures and connected in magnetism between and were assembled into a brain model.The midbrain can be separated into two equal parts.The mushroom body lobes were inset in the midbrain and the central body was in the center of the brain midline.In this study,the anatomical structures of brain of adult H.armigera were identified,the three-dimensional structures were reconstructed,and the digital models were printed by a 3D printer.These results provide knowledge that is essential for understanding the brain developing and behavioral regulation.The printed brain model provides a useful tool for teaching as well.