title: EEG effect of orexin A in freely moving rats.
abstract: Orexin A and orexin B are neuropeptides produced by a group of neurons located in the lateral hypothalamus which send widespread projections virtually to the whole neuraxis. Several studies indicated that orexins play a crucial role in the sleep-wake regulation and in the pathomechanism of the sleep disorder narcolepsy. As no data are available related to the EEG effects of orexin A in healthy, freely moving rats, the aim of the present experiments was to analyze EEG power changes in the generally used frequency bands after intracerebroventricular orexin A administration.Orexin A administration (0.84 and 2.8 nM/rat) differently affected fronto-occipital EEG waves in the different frequency bands recorded for 24 hours. Delta (1-4 Hz) and alpha (10-16 Hz) power decreased, while theta (4-10 Hz) and beta (16-48 Hz) power increased. Decrease of the delta power was followed by a rebound in case of the higher orexin A dose. This complex picture might be explained by the activation of several systems by the orexin A administration. Among these systems, cortical and thalamic circuits as well as the role of the neurons containing corticotrophin-releasing factor might be of significant importance.
authors.affiliation: Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary. etn@freemail.hu
authors.forename: A
authors.initials: A
authors.lastname: Toth
authors.forename: B
authors.initials: B
authors.lastname: Balatoni
authors.forename: T
authors.initials: T
authors.lastname: Hajnik
authors.forename: L
authors.initials: L
authors.lastname: Detari
mesh_terms: D000513:Alpha Rhythm / Q000187:drug effects; D000818:Animals; D001611:Beta Rhythm / Q000187:drug effects; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology; D002940:Circadian Rhythm / Q000187:drug effects*; D003700:Delta Rhythm / Q000187:drug effects; D004569:Electroencephalography / Q000187:drug effects*; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology; D007276:Injections, Intraventricular; D047908:Intracellular Signaling Peptides and Proteins / Q000494:pharmacology* / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009479:Neuropeptides / Q000494:pharmacology* / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000494:pharmacology* / Q000502:physiology; D000068797:Orexins; D051381:Rats; D017207:Rats, Sprague-Dawley; D012890:Sleep / Q000187:drug effects; D013788:Thalamus / Q000187:drug effects / Q000502:physiology; D013826:Theta Rhythm / Q000187:drug effects
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D000068797:Orexins