Collaborative coding rats working memory via mutual information on multi-channel θ band LFPs-Spikes / 国际生物医学工程杂志

ABSTRACT

Objective This paper aimed to investigate the collaborative coding of two different modes of neural signals including local field potentials and spiking activity (multi-unit activity) which recorded in medial prefrontal cortex of sprague-dawley (SD) rats in Y maze working memory (WM) task,to provide computing support for neural coding mechanism of WM.Methods 1.Experiment data was multi-channel neural signals (local field potentials (LFPs)-Spikes) recorded from prefrontal cortex of 4 SD rats during WM process and resting state,provided by the lab of Neuro-engineering,Tianjin Medical University.2.LFPs preprocessing included baseline drift removing and power-line noise eliminating.3.Physiology window width 500 ms,step 125 ms were selected and average rate per channel was calculated to turn the discrete point signal spikes to continuous signal.4.LFPs characteristic frequency band was obtained by using short time Fourier transform and signals of the characteristic frequency band were extracted by band pass filter.5.Mutual information (MI) of LFPs-spikes was computed to get the distribution of multi-channel MI values.Results 1.LFPs distribution demonstrated that the power focused at θ band (4-12 Hz)during the WM tasks.2.The average MI value of θ band LFPs and spikes (4 rats,over 10 trials) were 0.49±0.04,0.39±0.03,0.41±0.03,0.48±0.02,respectively,which were significantly larger than those in the resting state (t test,P＜0.05).Conclusions These findings indicate that θ band LFPs represents behavior correlated to WM and its synergy with spiking activity plays an important role in encoding WM task.