| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 3045710 | Clinical Neurophysiology | 2011 | 16 Pages |
A brief review of previous studies is presented on high frequency oscillations (HFOs)>300 Hz overlying the cortical response in the somatosensory evoked potential (SEP) or magnetic field (SEF) in humans as well as other mammals. The characteristics of somatosensory HFOs are described about reproducibility and origin (area 3b and 1) of the HFOs, changes during a wake-sleep cycle, effects of stimulus rate or tactile interference, and pharmacological effects. Also, several hypotheses on the neural mechanisms of the HFOs are reconsidered; the early HFO burst is probably generated from action potentials of thalamocortical fibers at the time when they arrive at the area 3b (and 1), since this component is resistant to higher stimulus rate >10 Hz, general anesthesia, or application of glutamatergic receptor antagonist: by contrast, the late HFO burst is sensitive to higher stimulus rate and eliminated after application of glutamatergic receptor antagonist, reflecting activities of a postsynaptic neural network in areas 3b and 1 of the somatosensory cortex. In view of physiological features of the somatosensory HFOs and their pathological or pharmacological changes, possible mechanisms of the late HFO burst genesis are discussed: a fast-spiking interneuron hypothesis, a fast pyramidal cell IPSP hypothesis and a chattering cell hypothesis.
► A brief history of somatosensory 600 Hz HFOs and their characteristics in humans and experimental animals are surveyed. ► The neural mechanisms of the HFOs are discussed in relation to their physiological and pathological features. ► Late HFOs can be useful in various CNS diseases for testing inhibitory function in somatosensory information processing.
