Biomaterial Database

The K-complex: its slow (<1-Hz) rhythmicity and relation to delta waves. 1997

F Amzica, and M Steriade

Laboratoire de Neurophysiologie, Faculté de Médecine, Université Laval, Quebec, PQ, Canada.

The K-complex is a major graphoelement of sleep EEG. This report demonstrates that K-complexes emerge from a cortically generated slow (<1-Hz) oscillation. Human EEG as well as cat cellular and field potential recordings converge into demonstrating that the K-complex results from a synchronized cortical network that imposes periodic excitatory and inhibitory actions on cortical neurons. We additionally show the correspondence between neuronal activities and the shape of the K-complex. Spectral analysis confirms the periodic recurrence of human K-complexes, with main peaks at 0.5 to 0.7 Hz. It is also shown that the spectral content in the delta band (1 to 4 Hz) is partially due to the shape and duration of the K-complex.

UI	MeSH Term	Description	Entries
D007649	Ketamine	A cyclohexanone derivative used for induction of anesthesia. Its mechanism of action is not well understood, but ketamine can block NMDA receptors (RECEPTORS, N-METHYL-D-ASPARTATE) and may interact with sigma receptors.	2-(2-Chlorophenyl)-2-(methylamino)cyclohexanone,CI-581,Calipsol,Calypsol,Kalipsol,Ketalar,Ketamine Hydrochloride,Ketanest,Ketaset,CI 581,CI581
D010507	Periodicity	The tendency of a phenomenon to recur at regular intervals; in biological systems, the recurrence of certain activities (including hormonal, cellular, neural) may be annual, seasonal, monthly, daily, or more frequently (ultradian).	Cyclicity,Rhythmicity,Biological Rhythms,Bioperiodicity,Biorhythms,Biological Rhythm,Bioperiodicities,Biorhythm,Cyclicities,Periodicities,Rhythm, Biological,Rhythmicities,Rhythms, Biological
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D003700	Delta Rhythm	Brain waves seen on EEG characterized by a high amplitude and a frequency of 4 Hz and below. They are considered the "deep sleep waves" observed during sleep in dreamless states, infancy, and in some brain disorders.	Delta Rhythms,Rhythm, Delta,Rhythms, Delta
D004569	Electroencephalography	Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.	EEG,Electroencephalogram,Electroencephalograms
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000778	Anesthetics, Dissociative	Intravenous anesthetics that induce a state of sedation, immobility, amnesia, and marked analgesia. Subjects may experience a strong feeling of dissociation from the environment. The condition produced is similar to NEUROLEPTANALGESIA, but is brought about by the administration of a single drug. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed)	Dissociative Anesthetics