Stable synchronized high-frequency signals from the main sensory and spinal nuclei of the pig activated by Aβ fibers of the maxillary nerve innervating the snout

Contributions of principal neocortical neurons to magnetoencephalography and electroencephalography signals

“…Assuming a rough value of 1 pA m for the dipole moment of a spike/cell, an ensemble of 10 000 synchronized neurons may produce a population Q of approximately 10 nA m. It has been assumed that sodium spikes do not contribute to MEG and EEG signals because the spikes produced by a population of pyramidal cells tend to cancel each other due to temporal jitter (De Munck et al 1992). However, recent studies indicate that the brain of many species is capable of producing spikes with an extremely high degree of synchronization having a temporal jitter of less than a millisecond (Jones et al 2000; Barth, 2003; Kato et al 2003). The temporal jitter is apparently sufficiently small for the detection of high‐frequency cortical signals (Curio et al 1994; Hashimoto et al 1996; Ikeda et al 2002, 2005).…”

Very Fast Oscillations Evoked by Median Nerve Stimulation in the Human Thalamus and Subthalamic Nucleus

“…Very-high-frequency oscillatory activity (Ͼ500 Hz) associated with sensory evoked potentials [very fast oscillations (VFOs)] can be recorded at many levels in the somatosensory system (Calvin and Loeser 1975;Curio et al 1994;Hashimoto et al 1996;Ikeda et al 2002;Kato et al 2003). Components with frequencies of 500 -700 Hz can be recorded from the human sensory cortex (S1) superimposed on the N20 wave (cortical potentials recorded from the scalp) (Curio 2000;Curio et al 1994;Hashimoto 2000;Hashimoto et al 1996).…”