It is a 3D view of a "V"-shaped cut of a fruit fly brain; such a segmentation was done using a deformable curve method (Lam, et al, Methods, 2010). The segmentation method, as well as both the 3D image visualization and 3D surface mesh generation, are all provided in V3D.

Ref: Shing Chun Benny Lam, Zongcai Ruan, Ting Zhao, Fuhui Long, Arnim Jenett, Julie Simpson, Eugene Myers, Hanchuan Peng, "Segmentation of center brains and optic lobes in 3D confocal images of adult fruit fly brains," Methods, Vol.50, No.2, pp.63-69, 2010. [ PDF: http://penglab.janelia.org/papersall/doc... ]