Mapping the Information Trace in Local Field Potentials by a Computational Method of Two-Dimensional Time-Shifting Synchronization Likelihood Based on Graphic Processing Unit Acceleration

Abstract

The local field potential (LFP) is a signal reflecting the electrical activity of neurons surrounding the electrode tip. Synchronization between LFP signals provides important details about how neural networks are organized. Synchronization between two distant brain regions is hard to detect using linear synchronization algorithms like correlation and coherence. Synchronization likelihood (SL) is a non-linear synchronization-detecting algorithm widely used in studies of neural signals from two distant brain areas. One drawback of non-linear algorithms is the heavy computational burden. In the present study, we proposed a graphic processing unit (GPU)-accelerated implementation of an SL algorithm with optional 2-dimensional time-shifting. We tested the algorithm with both artificial data and raw LFP data. The results showed that this method revealed detailed information from original data with the synchronization values of two temporal axes, delay time and onset time, and thus can be used to reconstruct the temporal structure of a neural network. Our results suggest that this GPU-accelerated method can be extended to other algorithms for processing time-series signals (like EEG and fMRI) using similar recording techniques.

Dependence of Generation of Hippocampal CA1 Slow Oscillations on Electrical Synapses

“…Three major types of neuronal oscillation occur in the in vivo hippocampus, as commonly demonstrated by LFP recording [11,32,33]: theta rhythms (*5 Hz-10 Hz, also suggested to have a broader range of 3 Hz-12 Hz), gamma rhythms (*30 Hz-80 Hz), and sharp wave-ripples (*110 Hz-250 Hz). In the completely isolated hippocampus, we found spontaneous CA1 oscillations (in both LFPs and V m changes) at 0.5 Hz-1.5 Hz, considerably slower than those found in vivo (e.g., compared with theta bands).…”