Serial optical coherence scanner for large-scale brain imaging at microscopic resolution

Abstract

We describe a serial optical coherence scanner (SOCS) for high resolution imaging of ex-vivo brain. SOCS integrates a multi-contrast optical coherence tomography and a vibratome slicer to establish comprehensive brain anatomy and fiber pathways in three-dimensional space. Rat brain images are demonstrated by utilizing intrinsic optical contrasts including back-scattering, birefringence and optic axis orientation, which are simultaneously generated from the same dataset. Volumetric images from serial scans are combined to realize large scale brain maps. Nerve fiber tracts are globally described in 3D by retardance, and delicately delineated by cross-polarization at the resolution of 15×15×5.5μm(3). In-plane orientations of the tracts are quantified by optic axis orientation. SOCS offers a new solution for complete reconstructions of macroscopic tissues such as primate and human brains at microscopic resolution. The technique also opens up varieties of opportunities for connectome studies and systematic investigations on neurological diseases and brain disorders.

Keywords: Brain anatomy; Connectivity; Fiber pathways; Nerve fiber orientation; Optical coherence tomography; Polarization.