Imaging developing neural morphology using optical coherence tomography

Abstract

Imaging technologies offer numerous possibilities to investigate the processes involved in neural development. The optical coherence tomography (OCT) technology is analogous to ultrasound backscatter microscopy except reflections of light are detected rather than sound. The OCT technology combines high-resolution in vivo imaging in a diode-based benchtop instrument capable of micron-scale resolution in transparent and non-transparent biological specimens. In this paper, we examine the potential of using OCT for the investigation of developing neural morphology. To demonstrate the capabilities of this technique in assessing neural development, we have chosen to image early normal and abnormal neural morphology in a common developmental biology model, Xenopus laevis. In vivo images clearly identify gross and subtle differences in neural structure and may offer an alternative to the costly and time-consuming process of repeated histological preparation for neural developmental studies. Because imaging can be performed rapidly and repeatedly, the morphological changes of single specimens can be followed throughout development. To illustrate the future potential of this technique, a state-of-the-art Cr4+:forsterite modelocked laser is used as a broad bandwidth light source to image individual cells in a developing specimen.