After one week of practicing with dr. Mike's tutorials, I was able to create 3D model of pyramidal neuron from 10gb CLSM (confocal laser scanning microscopy) Tiff slide. I almost burned my video card, but in the end I done it
First I used Fiji to convert .tiff slide to binary (Process/Binary/Make Binary). Then I used Dilate function to reduce the size (Process/Binary/Dilate) and I cropped one of the most promising neurons (Image/Crop). I saved my stack as a .tiff and I used 3D Slicer to create volume (Volume Rendering), to convert it to label map and to export it as .stl. Finally I used Meshmixer to remove the artifacts, to decrease my triangle budget and to add a mild smooth effect. The result is here. I hope my experience will help you in your future projects. I'll create video tutorial as soon as I can.