Spike — LFP encoding working memory in rat

Working memory (WM) refers to the short-term maintenance of information with higher cognitive functions. Recent researches show that local field potentials (LFPs) and spikes as different modes of neural signals encode WM respectively. There is a growing interest in how these two signals encode WM in coordination. The aim of this study is to investigate spike-LFP coupling coding WM via joint entropy analysis. The experimental data were multi-channels Spikes and LFPs obtained at prefrontal cortex with implanted microelectrode array in SD rats during WM tasks in Y-maze. The short-time Fourier transform (STFT) was applied to find the principle frequency range in the LFPs during WM. The joint entropy indexes (JEIs) between spikes and the principle components of LFPs were calculated for each pair of spike and LFP during WM. The results show that theta was the principle band in LFP for WM. The JEIs between Spikes and theta components of LFPs encode WM effectively. These findings could lead to improved understanding the mechanism of WM from the view of Spike-LFP joint encoding.