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Frequency-specific coupling in the cortico-cerebellar auditory system.

Pastor MA, Vidaurre C, Fernández-Seara MA, Villanueva A, Friston KJ - J. Neurophysiol. (2008)

Bottom Line: Using regional cerebral blood flow and positron emission tomography we previously confirmed frequency-selective cortical responses to 40-Hz tones in auditory primary cortices and concomitant bilateral activation of the cerebellar hemispheres.In this study, using functional magnetic resonance imaging (fMRI) we estimated the influence of 40-Hz auditory stimulation on the coupling between auditory cortex and superior temporal sulcus (STS) and Crus II, using a dynamic causal model of the interactions between medial geniculate nuclei, auditory superior temporal gyrus (STG)/STS, and the cerebellar Crus II auditory region.Our model comparison results suggest that input from auditory STG/STS to cerebellum is enhanced selectively at gamma-band frequencies around 40 Hz.

View Article: PubMed Central - PubMed

Affiliation: Centre for Applied Medical Research, Department of the Neurosciences, University of Navarra School of Medicine, CUN, 31080 Pamplona, Spain. mapastor@unav.es

ABSTRACT
Induced oscillatory activity in the auditory cortex peaks at around 40 Hz in humans. Using regional cerebral blood flow and positron emission tomography we previously confirmed frequency-selective cortical responses to 40-Hz tones in auditory primary cortices and concomitant bilateral activation of the cerebellar hemispheres. In this study, using functional magnetic resonance imaging (fMRI) we estimated the influence of 40-Hz auditory stimulation on the coupling between auditory cortex and superior temporal sulcus (STS) and Crus II, using a dynamic causal model of the interactions between medial geniculate nuclei, auditory superior temporal gyrus (STG)/STS, and the cerebellar Crus II auditory region. Specifically, we tested the hypothesis that 40-Hz-selective responses in the cerebellar Crus II auditory region could be explained by frequency-specific enabling of interactions in the auditory cortico-cerebellar-thalamic loop. Our model comparison results suggest that input from auditory STG/STS to cerebellum is enhanced selectively at gamma-band frequencies around 40 Hz.

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Left: depicts the frequency spectrum of echo planar imaging gradient waveforms. Right: a detailed look at the low-frequency spectrum, showing the relation with the auditory frequencies used in the experiment.
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f2: Left: depicts the frequency spectrum of echo planar imaging gradient waveforms. Right: a detailed look at the low-frequency spectrum, showing the relation with the auditory frequencies used in the experiment.

Mentions: Stimuli were trains of clicks delivered binaurally through headphones. The auditory stimuli were generated by Cogent 2000 software (Wellcome Trust Centre for Neuroimaging, London, UK). Stimulation comprised three types of click trains (three different frequencies: 40, 26, and 12 Hz) at 95-dB intensity. None of the frequencies included harmonics of the scanner noise (Fig. 2). Null events comprised only the scanner noise. To control attentional set, subjects were asked to make a motor response to white noise bursts. The trains (2-s duration) had the same sonority and the duration of every click was inversely correlated to frequency; clicks in the 40-Hz train were 1 ms; 26 Hz = 1.53 ms; and 12 Hz = 3.3 ms.


Frequency-specific coupling in the cortico-cerebellar auditory system.

Pastor MA, Vidaurre C, Fernández-Seara MA, Villanueva A, Friston KJ - J. Neurophysiol. (2008)

Left: depicts the frequency spectrum of echo planar imaging gradient waveforms. Right: a detailed look at the low-frequency spectrum, showing the relation with the auditory frequencies used in the experiment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2576217&req=5

f2: Left: depicts the frequency spectrum of echo planar imaging gradient waveforms. Right: a detailed look at the low-frequency spectrum, showing the relation with the auditory frequencies used in the experiment.
Mentions: Stimuli were trains of clicks delivered binaurally through headphones. The auditory stimuli were generated by Cogent 2000 software (Wellcome Trust Centre for Neuroimaging, London, UK). Stimulation comprised three types of click trains (three different frequencies: 40, 26, and 12 Hz) at 95-dB intensity. None of the frequencies included harmonics of the scanner noise (Fig. 2). Null events comprised only the scanner noise. To control attentional set, subjects were asked to make a motor response to white noise bursts. The trains (2-s duration) had the same sonority and the duration of every click was inversely correlated to frequency; clicks in the 40-Hz train were 1 ms; 26 Hz = 1.53 ms; and 12 Hz = 3.3 ms.

Bottom Line: Using regional cerebral blood flow and positron emission tomography we previously confirmed frequency-selective cortical responses to 40-Hz tones in auditory primary cortices and concomitant bilateral activation of the cerebellar hemispheres.In this study, using functional magnetic resonance imaging (fMRI) we estimated the influence of 40-Hz auditory stimulation on the coupling between auditory cortex and superior temporal sulcus (STS) and Crus II, using a dynamic causal model of the interactions between medial geniculate nuclei, auditory superior temporal gyrus (STG)/STS, and the cerebellar Crus II auditory region.Our model comparison results suggest that input from auditory STG/STS to cerebellum is enhanced selectively at gamma-band frequencies around 40 Hz.

View Article: PubMed Central - PubMed

Affiliation: Centre for Applied Medical Research, Department of the Neurosciences, University of Navarra School of Medicine, CUN, 31080 Pamplona, Spain. mapastor@unav.es

ABSTRACT
Induced oscillatory activity in the auditory cortex peaks at around 40 Hz in humans. Using regional cerebral blood flow and positron emission tomography we previously confirmed frequency-selective cortical responses to 40-Hz tones in auditory primary cortices and concomitant bilateral activation of the cerebellar hemispheres. In this study, using functional magnetic resonance imaging (fMRI) we estimated the influence of 40-Hz auditory stimulation on the coupling between auditory cortex and superior temporal sulcus (STS) and Crus II, using a dynamic causal model of the interactions between medial geniculate nuclei, auditory superior temporal gyrus (STG)/STS, and the cerebellar Crus II auditory region. Specifically, we tested the hypothesis that 40-Hz-selective responses in the cerebellar Crus II auditory region could be explained by frequency-specific enabling of interactions in the auditory cortico-cerebellar-thalamic loop. Our model comparison results suggest that input from auditory STG/STS to cerebellum is enhanced selectively at gamma-band frequencies around 40 Hz.

Show MeSH