@article {69110, title = {Imaging neuronal voltage beyond the scattering limit}, journal = {Nat Methods}, year = {2025}, month = {2025 May 19}, abstract = {

Voltage imaging is a promising technique for high-speed recording of neuronal population activity. However, tissue scattering severely limits its application in dense neuronal populations. Here, we adopted the principle of localization microscopy, a technique that enables super-resolution imaging of single-molecules, to resolve dense neuronal activities\ in vivo. Leveraging the sparse activation of neurons during action potentials (APs), we precisely localize the fluorescence change associated with each AP, creating a super-resolution image of neuronal activities. This approach, termed\ Activity\ Localization\ Imaging (ALI), identifies overlapping neurons and separates their activities with over 10-fold greater precision than what tissue scattering permits. Using ALI, we simultaneously recorded over a hundred densely-labeled CA1 neurons, creating a map of hippocampal theta oscillation at single-cell and single-cycle resolution.

Preprint:\ https://doi.org/10.1101/2023.12.03.56840

}, doi = {10.1038/s41592-025-02692-5}, url = {https://doi.org/10.1038/s41592-025-02692-5}, author = {Tsai-Wen Chen and Xian-Bin Huang and Sarah E. Plutkis and Katie L. Holland and Luke D. Lavis and Bei-Jung Lin} } @article {69205, title = {Synchronous Ensembles of Hippocampal CA1 Pyramidal Neurons Associated with Theta but not Ripple Oscillations During Novel Exploration.}, journal = {eLife}, year = {2025}, month = {2025 Apr 1}, abstract = {

Synchronous neuronal ensembles play a pivotal role in the consolidation of long-term memory in the hippocampus. However, their organization during the acquisition of spatial memory remains less clear. In this study, we used neuronal population voltage imaging to investigate the synchronization patterns of CA1 pyramidal neuronal ensembles during the exploration of a new environment, a critical phase for spatial memory acquisition. We found synchronous ensembles comprising approximately 40\% of CA1 pyramidal neurons, firing simultaneously in brief windows (\~{}25ms) during immobility and locomotion in novel exploration. Notably, these synchronous ensembles were not associated with ripple oscillations but were instead phase-locked to local field potential theta waves. Specifically, the subthreshold membrane potentials of neurons exhibited coherent theta oscillations with a depolarizing peak at the moment of synchrony. Among newly formed place cells, pairs with more robust synchronization during locomotion displayed more distinct place-specific activities. These findings underscore the role of synchronous ensembles in coordinating place cells of different place fields.

}, doi = {10.7554/elife.96718.2}, url = {https://doi.org/10.7554/elife.96718.2}, author = {Bei-Jung Lin and Tsai-Wen Chen and En-Li Chen and Eric R. Schreiter} } @article {46307, title = {A motor cortex circuit for motor planning and movement}, journal = {Nature}, volume = {519}, year = {2015}, month = {2015 Feb 25}, pages = {51-6}, abstract = {

Activity in motor cortex predicts specific movements seconds before they occur, but how this preparatory activity relates to upcoming movements is obscure. We dissected the conversion of preparatory activity to movement within a structured motor cortex circuit. An anterior lateral region of the mouse cortex (a possible homologue of premotor cortex in primates) contains equal proportions of intermingled neurons predicting ipsi- or contralateral movements, yet unilateral inactivation of this cortical region during movement planning disrupts contralateral movements. Using cell-type-specific electrophysiology, cellular imaging and optogenetic perturbation, we show that layer 5 neurons projecting within the cortex have unbiased laterality. Activity with a contralateral population bias arises specifically in layer 5 neurons projecting to the brainstem, and only late during movement planning. These results reveal the transformation of distributed preparatory activity into movement commands within hierarchically organized cortical circuits.

}, doi = {10.1038/nature14178}, author = {Nuo Li and Tsai-Wen Chen and Zengcai V. Guo and Charles R. Gerfen and Karel Svoboda} }