Exploring light propagation through brain tissue with adaptive multiphoton microscopy for improving deep tissue functional imaging
Project ID: 2228cd1326 (You will need this ID for your application)
Research Theme: Physical Sciences
UCL Lead department: Division of Biosciences
Lead Supervisor: Angus Silver
Project Summary:
Scattering of light limits the depth at which neuronal structures and functional signals can be imaged in the brain. The deleterious effects of scattering can be partially compensated for with adaptive optic devices (e.g. spatial light modulators) that modulate the optical wavefront. However, the properties of light propagation through tissue are poorly understood. The aim of this PhD project is to extend the depth of multiphoton functional imaging by measuring the spatial variations of refractive index of brain tissue on the microscopic scale and developing models of light propagation linking brain structures such as cell bodies and vasculature to refractive index variations and scattering. Model predictions will be used to develop fast model-based optical wavefront correction for adaptive optics devices extending the depth of two and three photon microscopy.
The student will measure scattering and wavefront distortions as infrared light propagates through slices of living brain tissue. These measurements will be used to compute the spatial variations in refractive index across the tissue and develop models of light propagation. The student will then move on to working with a prototype adaptive two and three-photon microscope, applying the understanding gained from modelling to predict the aberrations generated by tissue from stacks of images obtained from the brains of mice. This will enable the fastest possible high resolution 3D imaging of neuronal activity deep within the brain. It will suit a student keen to combine experiments and modelling.
The student will work mainly in the Silver lab at UCL, which developed Acousto-Optic Lens 3D microscopy and is currently building a novel adaptive multiphoton 3D microscope that combines two and three-photon imaging. Professor Silver collaborates closely with Peter Munro, Professor of Computational Optics, who will co-supervise the project.