Synchronization Likelihood Based Functional Connectivity Features of θ Band Local Field Potentials During Working Memory Task in Rats

Zhang Yan; Tian Xin

Abstract：Objective To investigate θ band functional connectivity features on the prefrontal cortex multi-channel local field potentials (LFPs) during the working memory task in rats.Methods The 16-channel LFPs in frontal cortex were recorded in adult male SD rats during the Y-maze working memory task.Short time Fourier transform frequency analysis was applied to analyze dynamic power changes of the data.The working memory related to θ band was selected,and the synchronization likelihood was applied to calculate the 16 channel synchronization likelihood matrix value S,clustering coefficient C and characteristic path length L in the working memory task.Then the results were compared with those in the resting state.Results Based on the time frequency analysis,the distribution of the LFPs energy density concentrated on θ band which extended from the reference point before 1 s to the infrared reference point.During the working memory task,the synchronization likelihood value of LFPs θ band Sp =0.6593 ±0.0220,while in resting state Sp =0.5104 ±0.0516.The most significant difference in the functional connectivity between the working memory task and the resting state was found when T =0.76.The LFPs θ band Cp =0.2206 ± O.0263 during working memory was significantly higher than Cp =0.1065 ± O.0237 in the resting state (P ＜ 0.05).The LFPs θ Lp =1.3110 ± 0.1318 during working memory was significantly lower than Lp =2.9329 ± 0.2763 in the resting state (P ＜ 0.05).Conclusion LFPs characteristic band is θ in rats during working memory task,and the functional connectivity features in the working memory task is much stronger than that in the resting state.