Measuring neural coupling from non-Gaussian power spectra of voltage traces taken from awake, behaving animals

Brains consist of complex networks of neurons possessing highly non-linear interactions, suggesting that neural systems will show cooperative dynamics. Previous studies of the non-Gaussian statistics of 1/f noise in spin glasses and amorphous semiconductors have revealed important information concerning interaction kinetics not available through other techniques. Five male Brown-Norway-Cross rats were chronically implanted with arrays of microwire electrodes from which local field potentials (LFPs) were recorded from the dorsocentral striatum as the animals performed complex navigational tasks. The power spectra displayed a frequency dependence significantly different from 1/f. The correlation coefficients of the Fourier transform of the LFPs from striatum showed significant non-zero correlations between frequencies separated by less than three octaves. This novel technique may be useful in measuring functional interactions in neural systems.