, 2004; Lörincz et al., 2008), and thalamic lesions have been reported to suppress cortical alpha activity (Ohmoto et al., 1978). We have recently demonstrated that the pulvinar regulates the degree of alpha-band synchrony between visual cortical areas based on behavioral demands (Saalmann et al., 2012). This suggests that the thalamus may be a vital node for supporting resting-state networks. Previous studies have indicated that spontaneous BOLD connectivity best correlates with slow (<0.1 Hz) cortical potentials (Nir et al., 2008). Consistent with these previous cortico-cortical studies, we showed Src inhibitor the highest correlations between power time series on a slow timescale

(<0.1 Hz) in our thalamo-cortical network. Such slow changes in LFP power match the main frequencies (<0.1 Hz) contributing to the BOLD signal. However, we also showed significant coherence between “raw” time series on a fast timescale. Both of these effects on slow and fast

timescales were associated with the same range of low-frequency oscillations (e.g., alpha power on a slow timescale and alpha coherence on a fast timescale). Computational modeling studies have proposed that interareal coupling on slow timescales can emerge from neural synchrony on fast timescales (Cabral et al., 2011; Honey et al., 2007). Our study provides an empirical demonstration that slow power fluctuations Doxorubicin chemical structure could reflect the faster coherent oscillations, linking the fMRI measure to neural interactions occurring on a timescale better suited to more detailed

information processing. In summary, our findings suggest that the following neural processes support BOLD connectivity: (1) phase-locking of low-frequency oscillations for effective information transmission between remote brain areas; (2) low-frequency oscillations modulating the higher-frequency activity of local information processing; and (3) the slow fluctuations in oscillatory power changes correlating with BOLD connectivity across distinct brain areas. Anesthesia Condition. Macaque monkeys (BU, BS, CA, HO, MC, and PH) were anesthetized with Telazol (tiletamine/zolazepam, 10 mg/kg, i.m., administered at regular intervals as needed to maintain anesthesia) and held securely in an all-plastic MR-compatible stereotaxic apparatus. Two to four PAK6 fMRI time series (1,125 measurements in each series) were acquired from each monkey during anesthesia (two sessions collected from monkey BU). The monkey’s eyes were closed, and the experiments were performed in darkness. We monitored respiration rate and pulse rate during scan sessions using an MR-compatible respiratory belt and a pulse oximeter (Siemens). fMRI data were acquired from monkey CA prior to implantation of the recording chamber. Resting State. Monkeys BU and BS each participated in three scan sessions, in which there were no behavioral requirements and they were free to move their eyes.