Application of 3D printing technology in neuroscience: production of customized guide cannulas for intrahippocampal injections

For several decades, guide cannula implantation has been considered a gold standard to target specific brain areas. This allows investigating brain functions in vivo by using different approaches such as drug infusions associated with electrophysiological recordings or behavioral studies. Given the increasing need to personalize these implants at affordable costs, our aim was to produce customized guide cannulas for intrahippocampal injections taking advantage of the 3D printing technology. We used a “Prusa i3” 3D printer based on Fused Deposition Modeling technology with polylactic acid thermoplastic polymer as printing material, chosen for its biocompatibility and biodegradability. The 3D components were designed in SolidWorks, whereas the computer numerical control code was generated by Simplify3D. Head mounts were designed according to Paxinos coordinates to reach the CA1 area of the hippocampus. Spinal needles, as a source of surgical steel guides, were cut to a proper length by a linear motion apparatus designed and 3D printed in our laboratory. To assess the quality and precision of our customized infusion system, guide cannulas were implanted into the dorsal hippocampi of wild type mice. Methylene blue was infused and brains were removed to confirm the correct cannulas localization. In conclusion, 3D printing technology might be a useful tool in neuroscience research to produce eco-friendly customized equipment with high versatility profile at low costs.