bioRxiv Science⌕ Search

Biology subjects

Madruga, B. A.

Publications and source records attributed to Madruga, B. A..

2 recordsLinked to original sources

Transverse Sheet Illumination Microscopy (TranSIM): A High-Speed Platform for Large-Scale Volumetric Imaging

Recording the neural activity of biological organisms is paramount in understanding how they process the world around them. Fluorescence microscopy has served as the standard in recording this neural activity due to its ability to capture large populations of neurons simultaneously. Recent efforts in fluorescence microscopy have been concentrated in imaging large scale volumes, however, most of these efforts have been limited by spatiotemporal and bandwidth constraints. We present a novel system called Transverse-Sheet Illumination Microscopy (TranSIM), which captures spatially separated planes onto multiple two-dimensional sCMOS sensors at near diffraction limited resolution with 1.0 {micro}m, 1.4 {micro}m, and 4.3 {micro}m (x, y, and z respectively). The parallel use of sensors reduces the bandwidth bottlenecks typically found in other systems. TranSIM allows for the capturing of data at large-scale volumetric field-of-views up to 748 x 278 x 100 {micro}m3 at 100 Hz. Moreover, we were able to capture smaller field-of-views of 374 x 278 x 100 {micro}m3 at a faster volumetric rate of 200 Hz. Additionally, we found that the systems versatile design allowed us the ability to change the vertical magnification programmatically rather than necessitating a change of objectives. With this system we were able to observe intricate communication between neuron populations separated by vast three-dimensional distances, raising the potential to answer complex questions in Neurobiology.

bioengineering↗

Open-source, high performance miniature multiphoton microscopy systems for freely behaving animals

Here we describe the development of the UCLA 2P Miniscope, an easily adopted, open-source miniature 2-photon microscope capable of recording calcium dynamics from neurons located in deep structures and in dendrites over a 445 m x 380 m field of view (FOV) during free behavior. The system weighs approximately 4g and utilizes two on-board silicon-based photon detectors for highly sensitive measurements. All hardware is designed for high performance and ease of assembly, while minimizing cost. To test the 2P miniature microscope, we recorded in three experimental conditions to highlight its capabilities during free behavior in mice. First, we recorded calcium dynamics from place cells in hippocampal area CA1. Next, we resolved calcium transients from dendrites in retrosplenial cortex during 30 minutes of free behavior. Last, we recorded dentate granule cell activity at a depth of over 620 m, through an intact hippocampal CA1 during an open field behavior. The dentate granule cell recordings, to our knowledge, are the first optical recordings from these neurons ever performed in the intact hippocampus during free behavior. The miniature microscope itself and all supporting equipment are open-source and all files needed for building the scope can be accessed through the UCLA Golshani Lab GitHub repository.

neuroscience↗