Cheree James

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We have previously demonstrated that selective modulation of vestibular inputs, via sinusoidal galvanic vestibular stimulation (GVS) delivered at 0.5-0.8 Hz, can cause partial entrainment of muscle sympathetic nerve activity (MSNA). Given that we had seen interaction between the dynamic vestibular input and the normal cardiac-locked MSNA rhythm, we tested(More)
We have previously shown that sinusoidal galvanic vestibular stimulation (sGVS), a means of a selectively modulating vestibular afferent input without affecting other inputs, can cause partial entrainment of muscle sympathetic nerve activity (MSNA). Given that motion sickness causes sweating and pallor, we tested the hypothesis that sGVS also entrains skin(More)
We tested the hypothesis that vestibular and cardiac rhythms compete to modulate muscle sympathetic nerve activity (MSNA) in human subjects. Sinusoidal galvanic vestibular stimulation was applied across the mastoid processes at each subject's cardiac frequency and at ±0.1, ±0.2, ±0.3 and ±0.6 Hz. Cyclic modulation of MSNA was weakest at this central(More)
Blood pressure is controlled on a beat-to-beat basis through fluctuations in heart rate and the degree of sympathetically-mediated vasoconstriction in skeletal muscles. By recording muscle sympathetic nerve activity (MSNA) at the same time as performing functional magnetic resonance imaging (fMRI) of the brain, we aimed to identify cortical structures(More)
The sympathetic innervation of the skin primarily subserves thermoregulation, but the system has also been commandeered as a means of expressing emotion. While it is known that the level of skin sympathetic nerve activity (SSNA) is affected by anxiety, the majority of emotional studies have utilized the galvanic skin response as a means of inferring(More)
The sympathetic division of the nervous system is critical for maintaining both resting arterial pressure and for producing changes in regional perfusion required by behavioral state changes. A primary determinant of arterial pressure is the level of vasoconstriction within skeletal muscle. It is well established that there is a tight relationship between(More)
In thermoneutral conditions resting skin sympathetic nerve activity (SSNA) is related to the level of arousal and emotional state. The brain regions responsible for the generation of spontaneous SSNA are not known. In the present study we used concurrent recordings of SSNA and brain activity in awake humans to identify cortical and subcortical areas(More)
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