@article {65321, title = {Rapid mesoscale volumetric imaging of neural activity with synaptic resolution.}, journal = {Nature Methods}, volume = {17}, year = {2020}, month = {2020 Mar 02}, pages = {291-4}, abstract = {

Imaging neurons and neural circuits over large volumes at high speed and subcellular resolution is a difficult task. Incorporating a Bessel focus module into a two-photon fluorescence mesoscope, we achieved rapid volumetric imaging of neural activity over the mesoscale with synaptic resolution. We applied the technology to calcium imaging of entire dendritic spans of neurons as well as neural ensembles within multiple cortical regions over two hemispheres of the awake mouse brain.

}, issn = {1548-7105}, doi = {10.1038/s41592-020-0760-9}, author = {Lu, Rongwen and Liang, Yajie and Meng, Guanghan and Zhou, Pengcheng and Svoboda, Karel and Paninski, Liam and Ji, Na} } @article {49597, title = {High-throughput synapse-resolving two-photon fluorescence microendoscopy for deep-brain volumetric imaging .}, journal = {eLife}, volume = {8}, year = {2019}, month = {2019 Jan 03}, abstract = {

Optical imaging has become a powerful tool for studying brains . The opacity of adult brains makes microendoscopy, with an optical probe such as a gradient index (GRIN) lens embedded into brain tissue to provide optical relay, the method of choice for imaging neurons and neural activity in deeply buried brain structures. Incorporating a Bessel focus scanning module into two-photon fluorescence microendoscopy, we extended the excitation focus axially and improved its lateral resolution. Scanning the Bessel focus in 2D, we imaged volumes of neurons at high-throughput while resolving fine structures such as synaptic terminals. We applied this approach to the volumetric anatomical imaging of dendritic spines and axonal boutons in the mouse hippocampus, and functional imaging of GABAergic neurons in the mouse lateral hypothalamus .

}, issn = {2050-084X}, doi = {10.7554/eLife.40805}, author = {Meng, Guanghan and Liang, Yajie and Sarsfield, Sarah and Jiang, Wan-Chen and Lu, Rongwen and Dudman, Joshua Tate and Aponte, Yeka and Ji, Na} } @article {49367, title = {In vivo measurement of afferent activity with axon-specific calcium imaging.}, journal = {Nature Neuroscience}, year = {2018}, month = {2018 Aug 20}, abstract = {

In vivo calcium imaging from axons provides direct interrogation of afferent neural activity, informing the neural representations that a local circuit receives. Unlike in somata and dendrites, axonal recording of neural activity-both electrically and optically-has been difficult to achieve, thus preventing comprehensive understanding of neuronal circuit function. Here we developed an active transportation strategy to enrich GCaMP6, a genetically encoded calcium indicator, uniformly in axons with sufficient brightness, signal-to-noise ratio, and photostability to allow robust, structure-specific imaging of presynaptic activity in awake mice. Axon-targeted GCaMP6 enables frame-to-frame correlation for motion correction in axons and permits subcellular-resolution recording of axonal activity in previously inaccessible deep-brain areas. We used axon-targeted GCaMP6 to record layer-specific local afferents without contamination from somata or from intermingled dendrites in the cortex. We expect that axon-targeted GCaMP6 will facilitate new applications in investigating afferent signals relayed by genetically defined neuronal populations within and across specific brain regions.

}, issn = {1546-1726}, doi = {10.1038/s41593-018-0211-4}, author = {Broussard, Gerard Joey and Liang, Yajie and Fridman, Marina and Unger, Elizabeth K and Meng, Guanghan and Xiao, Xian and Ji, Na and Petreanu, Leopoldo and Tian, Lin} }