The Local Field Potential In The Prefrontal Cortex And Striatum Encode The Reward Information And The Effective Connection Between Them

Prefrontal cortex and striatum are two major areas in the brain.Single-unit recording experiments have found that neurons in the prefrontal cortex and striatum can represent reward information,but it remains elusive whether and how local field potentials(LFPs)in the two areas encode reward information.To investigate these issues,we recorded LFPs simultaneously in the prefrontal cortex and striatum of two monkeys performing a reward prediction task(large reward vs small reward).Recorded LPF signals were transformed from the time domain to the time and frequency domain using the method of short-time Fourier transform(STFT).We calculated the power in each frequency and time,and examined whether they were different in the two reward conditions.The results showed that about 40%of the total recorded channels distinguished one reward condition from the other one.And the power in small reward trials was greater than the power in large reward trials.Furthermore,it was found that the LFPs better encoded reward information in the beta band(14-30 Hz)than other frequency bands.Our results suggested that the LFPs in the prefrontal cortex and striatum effectively represented reward information,which would help to further understand functional roles of LFPs in reward processing.Meanwhile,we calculate the connection coefficient of the prefrontal cortex to the striatum's and the striatum to the prefrontal cortex 's,using granger prediction's toolbox-Granger Causal Connectivity Analysis(GCCA),the result show that:no matter big or small reword condition,the connection strength are both increased,and the direction of the striatum to the prefrontal cortex increased more,this illustrate the striatum may provide more information.