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PubMed1988

Objective characterization and differentiation of sleep states in healthy newborns and newborns-at-risk by spectral analysis of heart rate and respiration rhythms.

Best parameters of power and coherence spectra of heart rate fluctuations (HR) and respiration rhythms (RR) were established to differentiate sleep states in healthy newborns and newborns-at-risk by means of multivariate variance and discriminant analysis. Nine healthy newborns and 20 newborns with low risk features were examined polygraphically. Long-term-variability of both HR and RR and coherence between HR and RR in the frequency range of 0.26-0.97 Hz, corresponding to Respiratory Sinus Arrhythmia, allow the best differentiation of neonatal sleep states S 1 and S2. Differentiation of healthy newborns and newborns-at-risk by these parameters was not possible. Thus, in studies dealing with low risk features in newborns sleep states must be previously classified. State 1 and 2 represent different autonomic organisations. State 1 is a neuro-vegetative, relatively stable state. State 2 shows cyclic increases of coherence between HR and RR within the frequency range of Respiratory Sinus Arrhythmia. These properties are related to autonomic brain stem functions and were absent in 6 out of the 20 newborns-at-risk.

Heart Rate↗
PubMed1987

Spectral analysis of respiratory parameters in defensive respiratory reflexes.

A detailed analysis of respiratory signals in normal breathing and defensive respiratory reflexes was performed to obtain maximum information that can be used for modelling of respiratory processes. Physiological interpretation of the problem is difficult and requires further measurements to achieve convincing conclusions. We suggest therefore that the search for appropriate methodological backgrounds should contribute to further clarification of the problems concerned with reciprocal linkage of the respiratory signals. Appropriate attention must be paid to investigations aimed at explaining the regulatory mechanisms of breathing.

Animals↗
PubMedDate not supplied

ECoG spectral analysis of apamin effects on the rat brain with pretrigeminal or high spinal transection of the central nervous system.

Rats were injected into one lateral ventricle (icv) with apamin (50 and 100 ng per animal). The resulting desynchronization pattern in the electro-corticogram (ECoG) and the symptoms of apaminism (uncoordinated hypermotility and jerks) were monitored. The results of presented experiments contributed additional data concerning the topography of apamin effects. When injected into the ventricle of intact rats, generalized apaminism and massive desynchronization (reduction of total power and increase in beta waves band) of the cortical ECoG emerged. Transection of the spinal cord at the C1-C2 level (encéphalé isolé preparation) displayed apaminism of the head together with significant decrease in the total and relative power connected with a significant decrease in both beta and theta waves. Pretrigeminal transsection of the brain stem abolished the desynchronization in ECoG, whereas the generalized apaminism persisted, however it occurred after a longer latency than in intact animals. Morphine (10 mg/kg, sc) reversed the ECoG effects of apamin in intact rats but remained without effect on the motility changes. Our data indicate that apamin acts primarily on the brain stem and spinal cord, i.e. the structures possessing a sensory input, and by that way indirectly on the higher integrating systems.

Anesthesia↗