Biophys Physicobiol
September 2017
It is established knowledge that the action potential event of nerves is formed by the combination of a phasic inward Na current and a following outward K current which increases gradually. These changes in current are commonly referred to as conductance changes of channels for Na and K with time. On the other hand, electric requirements for action potential generation in phenomena such as anode break excitation, hyperpolarizing break stimulation and accommodation, strongly suggest an existence of an inductance factor in the plasma membrane of nerves.
View Article and Find Full Text PDFA surface electromyogram (EMG), especially when recorded near the neuromuscular junction, is expected to contain the endplate potential (EPP) component which can be extracted with an appropriate signal filter. Two factors are important: the EMG must be recorded in monopolar fashion, and the recording must be done so the low frequency signal corresponding the EPP is not eliminated. This report explains how to extract the EPP component from the EMG of the masseter muscle in a human subject.
View Article and Find Full Text PDFTemporomandibular disorders (TMD) represent a group of chronic painful conditions in the masticatory musculature and temporomandibular joint. To examine possible changes in cortical machinery in TMD patients, we compared neuromagnetic signals evoked by cortical neurons between healthy subjects and TMD patients while they were carefully observing the video frames of jaw-opening movements performed by another person. During the movement observation task in the healthy subjects, we found cortical activation in the following sequence with left hemisphere dominance: (1) the occipitotemporal region near the inferior temporal sulcus (human homologue of MT/V5 in monkeys), (2) the inferior parietal cortex (IPC), and (3) the anterior part of the inferior-lateral precentral gyrus (PrCG).
View Article and Find Full Text PDFThe position of the neuromuscular junction of the human masseter muscle has estimated from the low frequency component of the surface electromyogram. Monopolar surface electromyograms were recorded in response to clenching from eight sites with the reference electrode placed on the tip of the nose in six healthy male subjects. Component of the slow wave was separated from the raw recordings using digital filter, and the difference of the polarity and magnitude with the sites was examined.
View Article and Find Full Text PDFThe feasibility of precise mapping was investigated noninvasively on the face component in predominantly unilateral primary somatosensory cortices (SI) in six healthy subjects. We recorded somatosensory evoked magnetic fields (SEFs) from the SI and secondary somatosensory cortices (SII) following the electrical stimulation of six skin sites: the infraorbital foramen, the angle of mouth, the upper lip, the lower lip, the mental foramen, and the mandibular angle. The median nerve at the wrist was stimulated as a standard of the map.
View Article and Find Full Text PDFPrevious studies have indicated that the geniohyoid (GH) muscle is innervated by efferent axons from both the hypoglossal nerve (CN XII) and ansa cervicalis. To clarify the physiological significance of this dual innervation of the GH muscle, we examined properties of efferent innervations in rat GH muscle using electrophysiological, horseradish peroxidase (HRP) tracing and immunohistochemical techniques. Recordings from the branch of the XII nerve that innervates the GH (GH.
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