Peering into the 3D world of rat brain tissue with digital holographic microscopy

Mapping the human brain’s microscopic architecture requires advanced imaging techniques. Conventional microscopy measures transmitted light intensity through thin brain sections, while digital holographic microscopy captures both transmitted amplitude and phase, encoding 3D structural information in a hologram. Despite its promise, applying holography to brain tissue has been hindered by biological complexity. In this study, we integrate in-line holography with bright-field microscopy to capture the first holograms of rat brain tissue to our knowledge. Using Double Side Band (DSB) filtering with a Spatial Light Modulator (SLM), we effectively achieve high-contrast amplitude and phase maps with 2.5μm lateral resolution. By solving the diffraction equation, we reconstruct 3D tissue volumes with submicron axial precision. This method, offering amplitude and phase modalities alongside conventional imaging, holds promise for advancing volumetric brain mapping at microscopic scales.