Biology subjects

Manita, S.

Publications and source records attributed to Manita, S..

3 recordsLinked to original sources

bioRxiv2024

Isotonic and minimally invasive optical clearing media for live cell imaging ex vivo and in vivo

Tissue clearing has been widely used for fluorescence imaging of fixed tissues, but not for live tissues due to its toxicity. Here we develop minimally invasive optical clearing media for fluorescence imaging of live mammalian tissues. Light scattering is minimized by adding spherical polymers with low osmolarity to the extracellular medium. A clearing medium containing bovine serum albumin (SeeDB-Live) is minimally invasive to live cells, allowing for structural and functional imaging of live tissues, such as spheroids, organoids, acute brain slices, and the mouse brain in vivo. SeeDB-Live minimally affects the electrophysiological properties and sensory responses of neurons. We demonstrate its utility for widefield imaging of subcellular voltage dynamics, such as backpropagating action potentials, in acute brain slices. We also utilize SeeDB-Live for widefield voltage imaging of dozens of dendrites in vivo, demonstrating population dynamics. Thus, SeeDB-Live expands the scale and modalities of fluorescence imaging of live mammalian tissues.

neuroscience↗

bioRxiv2023

A multicolor suite for deciphering population coding in calcium and cAMP in vivo

cAMP is a pivotal second messenger regulated by various upstream pathways including Ca2+ and G protein-coupled receptors (GPCRs). To decipher in vivo cAMP dynamics, we rationally designed cAMPinG1, an ultrasensitive genetically encoded green cAMP indicator that outperformed its predecessors in both dynamic range and cAMP affinity. Two-photon cAMPinG1 imaging detected cAMP transients in the somata and dendritic spines of neurons in the mouse visual cortex on the order of tens of seconds. In addition, multicolor imaging with a highly sensitive new red Ca2+ indicator RCaMP3 allowed simultaneous measurement of population patterns in Ca2+ and cAMP in hundreds of neurons. We identified Ca2+-induced cAMP responses that represented specific information, such as direction selectivity in vision and locomotion, as well as GPCR-induced cAMP responses. Overall, our multicolor suite revealed that information encoded in Ca2+ and GPCRs signaling is integrated and stored as cAMP transients for longer periods in vivo. HighlightsO_LIDeveloping an ultrasensitive cAMP indicator, cAMPinG1, for visualizing cAMP transients in somata and dendritic spines in vivo. C_LIO_LIDeveloping a highly sensitive red Ca2+ indicator, RCaMP3, for visualizing Ca2+ transients in large neuronal population. C_LIO_LIDual-color Ca2+ and cAMP imaging for dissecting Ca2+-induced and GPCR-induced cAMP responses. C_LIO_LISingle-cell, single-timepoint cAMP imaging for GRCR biology and drug screening. C_LI

neuroscience↗

bioRxiv2022

Cerebellar climbing fibers convey behavioral information of multiplex modalities and form functional modules

Cerebellar climbing fibers (CFs) convey sensorimotor information and their errors, which are used for motor control and learning. Furthermore, they represent reward-related information. Despite such functional diversity of CF signals, it is still unclear whether each CF conveys the information of single or multiple modalities and how the CFs conveying different information are distributed over the cerebellar cortex. We performed two-photon calcium imaging from cerebellar Purkinje cells (PCs) in mice engaged in a voluntary forelimb lever-pull task and demonstrated that CF responses in 93% of PCs could be explained by the combination of multiple behavioral variables, such as lever movement, licking, and reward delivery. Neighboring PCs exhibited similar CF response properties, formed functional clusters, and shared noise fluctuations of responses. Taken together, individual CFs convey behavioral information on multiplex variables and are spatially organized into the functional modules of the cerebellar cortex.

neuroscience↗