Please join us for this week's NCA Group meeting with guest speaker, Jason Moore (NYU Langone), who will be presenting"Segmentation and Signal Extraction for Dense Dendritic Datasets." Abstract below!
ABSTRACT: 2-photon calcium imaging allows the simultaneous recording of neural activity across a wide field of view. To date, software suites and analysis methods dealing with such data are optimized for either sparsely expressing samples or for fields of view populated by largely non-overlapping cell bodies. Our experiments in Jayeeta Basu's lab allow us to simultaneously visualize the activity of both soma and apical and basal dendrites in hippocampal area CA3, an important area for spatial representation and pattern completion. But the dense nature of expression brings new challenges for analyzing this data. First, due to heterogeneity of shapes, regions of interest defining individual soma and dendrites are typically hand drawn. I will describe efforts to automate the process of identifying this process using simple flood-filling strategies. Second, proper signal extraction from overlapping dendritic segments is crucial to understanding soma-dendrite correlations. I will demonstrate instances in which de-mixing via CNMF does not match expectations, and describe efforts to address this using a modified objective function - minimizing the L1, rather than L2, norm - and using supplementary "eligibility" traces. These problems are not solved, and I welcome and encourage discussion about different approaches.
Please feel free to convene in the 7th Floor Classroom if you are onsite, and if tuning in remotely, please use the zoom credentials below.