Spectral analysis of cortical and subthalamic local field potentials.

<p>Representative examples (A) of oscillatory activity in the raw local field potentials (LFP) recorded from STN (upper row) and frontal ECoG (lower row) of controls (left column) and 6-OHDA treated parkinsonian rats (right column). Time-frequency plots (B) of spectral power during 180 s of quiet rest from all PD animals included in gene expression analyses. Power spectra (C) calculated from frontal ECoG and STN-LFP data of parkinsonian rats (light gray lines/shadings) and controls (dark gray lines/shadings): (i) low-frequency range (1–45 Hz) and (ii) high-frequency range (45–80 Hz) of ECoG-power spectra pooled across all hemispheres (n = 6). (iii) Low-frequency power spectrum of STN-LFP ipsilateral to the side of HFS and (iv) contralateral to the side of HFS (n = 3 each). (v) High-frequency power spectrum of STN-LFP pooled across all hemispheres. Asterisks indicate significantly different frequency bands. Note the dampening at 50 Hz that resulted from bandpass filtering of line noise. LFP, local field potential; STN, subthalamic nucleus; ECoG, electrocorticogram; 6-OHDA, 6-hydroxydopamine, HFS, high-frequency stimulation.