Heterogeneity in Neuronal Calcium Spike Trains based on Empirical Distance

Abstract

Statistical similarities between neuronal spike trains could reveal significant information on complex underlying processing. In general, the similarity between synchronous spike trains is somewhat easy to identify. However, the similar patterns also potentially appear in an asynchronous manner. However, existing methods for their identification tend to converge slowly, and cannot be applied to short sequences. In response, we propose Hellinger distance measure based on empirical probabilities, which we show to be as accurate as existing techniques, yet faster to converge for synthetic as well as experimental spike trains. Further, we cluster pairs of neuronal spike trains based on statistical similarities and found two non-overlapping classes, which could indicate functional similarities in neurons. Significantly, our technique detected functional heterogeneity in pairs of neuronal responses with the same performance as existing techniques, while exhibiting faster convergence. We expect the proposed method to facilitate large-scale studies of functional clustering, especially involving short sequences, which would in turn identify signatures of various diseases in terms of clustering patterns.

Correlation in Neuronal Calcium Spiking: Quantification based on Empirical Mutual Information Rate

“…However, these methods have slow convergence i.e., they need large length spike trains for estimation, with out identifying the fact that the neuronal information changes in short time windows [7]. In this backdrop, we propose a fast yet accurate empirical method to estimate the mutual information rate by exploiting memory structures in calcium 1 Indian Institute of Technology Hyderabad, Telangana, India 2 The University of Toledo, Ohio, USA spike trains [8], [9]. Our method has shown superiority over existing LZ algorithms with example Markov processes and with heterogeneous calcium responses, recorded from hippocampal region of the brain, where memory and learning tasks performed.…”