{"id":576,"date":"2022-07-13T11:49:07","date_gmt":"2022-07-13T15:49:07","guid":{"rendered":"https:\/\/sites.bu.edu\/nil\/?page_id=576"},"modified":"2024-07-31T17:34:18","modified_gmt":"2024-07-31T21:34:18","slug":"news","status":"publish","type":"page","link":"https:\/\/sites.bu.edu\/nil\/news\/","title":{"rendered":"News"},"content":{"rendered":"

Open source mesoscope for imaging of two fluorophores and quantitative hemodynamics<\/h3>\n

\"\"Wide field microscopy of the entire dorsal part of the mouse cerebral cortex enables large-scale imaging of spontaneous and evoked neuronal activity. This type of microscopy is perfectly suited to study interactions between cortical regions, particularly when cellular resolution is not required. Thanks to recent advances in molecular engineering, we have an array of fluorescent probes reporting different aspects of neuronal activity including changes in neuronal intracellular calcium concentration and release of specific neurotransmitters such as acetylcholine (ACh). These probes have different spectral variants allowing color multiplexing. Neuronal activity in vivo is coupled with changes in blood volume and hemoglobin oxygenation. These \u201chemodynamic\u201d changes produce unwanted darkening of fluorescence signals due to light absorption by oxy- and deoxyhemoglobin (Hb and HbO), and simultaneous quantification of changes in hemoglobin concentration and oxygenation allows to correct this artifact. Furthermore, simultaneous imaging of neuronal activity and hemodynamics is needed for neurovascular studies. <\/span><\/p>\n

In this paper<\/a>, we describe an open-source instrument that allows concurrent imaging of red and green fluorescence as well as hemodynamic imaging and quantification of Hb\/HbO changes. The two-channel fluorescence imaging is performed in the epi-illumination mode. For absorption (hemodynamic) imaging, we use LEDs of two colors printed on a ring around the objective. During data acquisition, we strobe all four light sources for near-simultaneous acquisition of two fluorescence and two absorption time series. The LED ring serves as a wide base for a 3D-printed conical frustum that is placed in between the objective and a curved \u201ccrystal skull\u201d cranial window. This design avoids unwanted visual stimulation from the strobing lights and provides diffuse, reflection-free illumination of the curved glass for absorption imaging. A single CMOS detector is used for detection of fluorescence and absorbance. The acquisition is controlled by a Matlab code interfacing with a National Instruments DAQ device.<\/p>\n\n\n\n
Meet first author
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\nPatrick Doran<\/td>\n		Meet senior author
\n\"\"
\nDr. Martin Thunemann<\/td>\n		Widefield in vivo<\/em> imaging system with two fluorescence and two reflectance channels, a single sCMOS detector, and shielded illumination<\/strong><\/a><\/p>\n

Patrick R. Doran et al.<\/p>\n

Contact Patrick Doran<\/em><\/strong> at pdoran@bu.edu<\/a> or Dr. Martin Thunemann<\/em><\/strong> at martinth@bu.edu<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Sensing neuronal activity in transplanted cortical organoids<\/h3>\n

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