For each session a tetrode, consisting of four platinum/tungsten core channels embedded in a quartzite probe

with a triangular/center configuration (Thomas Recording imped: 500 KΩ–1.4 MΩ) was inserted through a stainless steel guide tube positioned in a grid system (Crist Instruments) within the recording chamber. The recording tip of the tetrode was physiologically monitored as it was driven down to target by a microdrive (Nan Drives, Israel). Continuous LFP recordings were drawn from one of four tetrode channels. Signals were preamplified with unity gain (Plexon headstage), and then amplified PD0332991 manufacturer (5,000–20,000 X), and bandpassed (0.7 Hz–170 Hz) using the Plexon Muti-channel Acquisition Processor (MAP) system. Signals were digitized at 1 KHz, and saved to disk for offline analysis. Offline analyses were conducted using MATLAB scripts developed

for the current project, and incorporated the Chronux toolbox (P. Mitra at Cold Spring Harbor Laboratories). The LFP signals for each session were separated into 4 s sweeps coinciding with the trial onsets and offsets. Individual LFP sweeps were inspected for noise and artifacts that saturated the amplifiers, with the sweeps that violated these criteria being removed from further analyses. Sixty hertz line noise was digitally removed using Butterworth filters (MATLAB signal processing toolbox). Each sweep was converted LBH589 price into an individual spectra of frequency and power across the 4 s duration, using five discrete prolate spheroidal sequence (DPSS) data

tapers applied to a 300 ms sliding window, stepped at 50 ms intervals, giving a 10 Hz aggregate resolution. Specific trial type comparisons of the LFP spectra were made for the nonoverlapping spectra bandwidths of gamma (30–100 Hz) and beta (10–25 Hz) across predetermined epochs based on the previous single unit findings of Wirth et al., 2003 and Wirth et al., 2009. Human BOLD fMRI data were pooled from two studies that employed the same conditional-motor-associative learning task for a total of 31 subjects (Kirwan et al., 2007 and Law et al., 2005). Subjects were solicited from the John Hopkins community and paid for Org 27569 their participation. Thirteen of the subjects were male, 18 were female, and all subjects were right handed with a mean age of 26.7 years (range 18–33). Imaging data were collected using a Phillips 3.0 Tesla scanner (Best, The Netherlands) equipped with a SENSE (sensitivity encoding) head coil. Functional echoplanar images were collected via a high-speed single-shot pulse sequence with an 80 × 80 acquisition matrix size, a 30 ms echo time, a 70° flip angle, a SENSE factor of 2, and a 3 × 3 mm in-plane acquisition resolution. Two acquisitions per trial for 132 trials per run made for a total of 264 whole-brain three-dimensional volumes that were acquired with a repetition time (TR) of 1.5 s for each run.