A 3D-printed interface holding chamber for rodent brain slice electrophysiology

Abstract

Ex vivo rodent brain slices are used extensively in biomedical research to study neurophysiological processes such as synaptic transmission, seizures, and spreading depolarization. These experiments require holding chambers to maintain brain tissue health between preparation and experimentation. Interface holding chambers, in which rodent slices rest at the solution interface rather than fully submerged, outperform submersion holding chambers at preserving brain slice health and connectivity, particularly over extended periods of time. Commercial interface holding chamber designs are available but costly, and custom versions require functionally rigid materials or specialized fabrication equipment. Although 3D-printed submersion holding chamber models have been reported, no fused deposition modeling (FDM) interface holding chamber design has been published to date. Moreover, existing FDM submersion designs rely on an external beaker for solution containment, resulting in large solution volumes and limited customizability. Here, we present an affordable FDM interface holding chamber, fabricated from PETG or PLA and sealed with MAX CLR epoxy, that independently holds solution and overcomes limitations of previous FDM submersion chamber designs. Moreover, the interface functionality, greater stability, and reduced solution volume support preserved network activity in rodent slices. At a cost of less than ten dollars, this design delivers quality performance with the accessibility and flexibility of FDM fabrication.