New view on cerebellar cortical background activity in rat: simulation

The aim of this study was to reveal the nature and meaning of interspike background activity (RBA) recorded in Prukinje cell layer of rat cerebellum. We compared Fourier amtplitude spectra of recorded, extracted and averaged simple spike(s)—SS and complex spike(s)—CS with the mean amplitude spectrum of the remaining interspike RBA. A much greater similarity of spectral characteristics was noticed between SS and RBA, than between CS and RBA. Then, we simulated background activity (SBA), by superimposing averaged SS with randomized amplitudes and time delays. There was a significant correlation (p<0.005) between linearly transformed simulated and recorded amplitude spectra. Mean amplitude spectra of SBA were positively correlated with the number of superimposed SS. We propose to use this fact as a qualitative indication about the direction of change in the mean activity of surrounding neuronal population.