Couplings Of Local Field Potential Signals In NCL And Hp Of Pigeon In Goal-directed Behavior

Different frequency signals in the brain are closely related to different behavioral activities,while the coupling of signals in different frequency bands is related to higher order brain activities.The hippocampus(Hp)of pigeon is responsible for memory storage in goal-directed behavior,and the nidopallium caudolaterale(NCL)has the ability to perceive and integrate information.However,it is not clear in the current study how the nerve signals between the two brain areas are transmitted and affected.In order to solve this problem,this paper takes the local field potential(LFP)signals from pigeon Hp area and NCL area in the goal-directed behavior as the research object,and use phase to amplitude coupling,phase transfer entropy method and so on to analyze the coupling characteristics of different frequency bands in single brain region and double brain regions between Hp and NCL,explore the relationship between cross-frequency coupling and goal-directed behavior,and inquire the information exchange and transfer mechanism between Hp and NCL.The specific research results are summarized as follows:(1)The coupling characteristics of low and high-frequency in the LFP signals from Hp region and NCL region single brain region are extracted by the phase-amplitude coupling method,and the specific relationship between the characteristics and turning behavior is analyzed.On the basis of determining that theta and gamma are related to turning behavior,the theta and gamma coupling phenomenon of in each brain region during each phase of the behavior is analyzed by using the phase-amplitude coupling method.It is found that not only the low and high frequency coupling processes of Hp region and NCL region are different,but also the distribution pattern of the gamma amplitude of each brain region in the theta rhythm cycle is obviously different.The theta-gamma coupling in NCL region is the strongest in turning and is directly related to selecting direction behavior,and the theta-gamma coupling in Hp region contains location information.(2)Through the analysis of the low and high-frequency coupling phenomenon across the two brain circuits,it is found that the low and high-frequency coupling is related to the overall and local information transmission and integration.Based on the analysis of the cross-frequency coupling characteristics of the cross-brain region of Hp-NCL during the whole behavior by using the phase-amplitude coupling method,and supported by the existing literature,an explanation was made for the formation of the cross-frequency coupling of the cross-brain region of Hp-NCL: the oscillations of 2-12 Hz theta band of between Hp and NCL are used as the network medium for cross-brain communication.High frequency such as gamma oscillations,which is related to specific brain activity or behavior,completes the process of local information integration into the overall network by coupling with low frequency theta,so as to realize the information interaction between Hp and NCL.Then the phase coherence method was used to analyze the phase synchronization between the Hp region and the NCL region,and it was determined that the 2-12 Hz theta band was at a higher level than other bands in the whole behavior process.Finally,the information flow direction between Hp-NCL is analyzed by the phase transfer entropy method.The rationality of the explanation is proved by combining the information flow characteristics of each stage.The information interaction mechanism between Hp-NCL is preliminarily revealed.