| Author/Editor | Musizza, Bojan; Stefanovska, Aneta; McClintock, Peter V; Paluš, Milan; Petrovčič, Janko; Ribarič, Samo; Bajrović, Fajko | |
| Title | Interactions between cardiac, respiratory, and EEG-delta oscillations in rats during anaesthesia | |
| Type | članek | |
| Source | J Physiol | |
| Vol. and No. | Letnik 580, št. 5 | |
| Publication year | 2007 | |
| Volume | str. 315-26 | |
| Language | eng | |
| Abstract | We hypothesised that, associated with the state of anaesthesia, there exist characteristic changes in both cardio-respiratory and cerebral oscillator parameters and couplings, perhaps varying with depth of anaesthesia. Electrocardiograms (ECGs), respiration and electroencephalograms (EEGs) were recorded from two groups of 10 rats during the entire course of anaesthesia following the administration of a single bolus of ketamine-xylazine (KX group) or pentobarbital (PB group). The phase dynamics approach was then used to extract the instantaneous frequencies of heart beat, respiration and slow delta-waves (within 0.5-3.5 Hz). The amplitudes of delta- and vartheta-waves were analysed by use of a time-frequency representation of the EEG signal within 0.5-7.5 Hz obtained by wavelet transformation, using the Morlet mother wavelet. For the KX group, where slow delta-waves constituted the dominant spectral component, the Hilbert transform was applied to obtain the instantaneous delta-frequency. The vartheta activity was spread over too wide a spectral range for its phase meaningfully to be defined. For both agents, we observed two distinct phases of anaesthesia, with a marked increase in vartheta-wave activity occurring on passage from a deeper phase of anaesthesia to a shallower one. In other respects, the effects of the two anaesthetics were very different. For KX anaesthesia, the two phases were separated by a marked change in all three instantaneous frequencies: stable, deep, anaesthesia with small frequency variability was followed by a sharp transition to shallow anaesthesia with large frequency variability, lasting until the animal awoke. The transition occurred 16-76 minutes after injection of the anaesthetic, with simultaneous reduction in the delta-wave amplitude. (Abstract truncated at 2000 characters) | |
| Descriptors | ANESTHESIA ELECTROCARDIOGRAPHY ELECTROENCEPHALOGRAPHY RESPIRATION KETAMINE XYLAZINE PENTOBARBITAL RATS, WISTAR |