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Biomedical subjects

C C Turbes

Publications and source records attributed to C C Turbes.

At least 37 records · Page 2Linked to original sources
PubMed1990

Autoregressive spectral filter studies on the sensorimotor rhythm EEG state variable.

These studies concern the EEG rhythms of the sensory motor cortex in cats. The cat generates a 12H to 16Hz rhythm related to the MU (Rolandic) rhythm in man. The behavioral state required to generate the rhythm in man and the cat requires complete immobility and alertness. The MU rhythm in man centers around 9Hz and in the cat at 12Hz to 16Hz. This rhythm is used in the biofeedback training for the treatment of intractable seizures in man. It has also been used (12 Hz to 16 Hz) experimentally in animals. It is necessary to enhance the MU rhythm and simultaneously depress the seizure activity. Our interest has been to detect and enhance the SMR rhythm (12 H to 16 Hz) in the cat. We found that when it is enhanced it also enhances the amplitude of auditory evoked potentials in other brain regions.

Algorithms↗
PubMed1990

Forty hertz (40Hz) and sensorimotor rhythms (SMR) as EEG state variables and related evoked potentials.

There is evidence that certain brain rhythms may signal the occurrence of different brain states. Support for this hypothesis may be provided by evidence that processing of information is changed during different brain states. The prestimulus period proceeding the auditory evoked potential (AEP) is converted to a power spectral estimate. These power spectra are used to sort for the AEP when certain power values for the (36-42Hz) and the (11-16Hz) are reached in the prestimulus period of the sensory motor cortex, nucleus accumbers and amygdala. Attempts are made to measure the performance of the 40Hz and SMR estimators. These studies are made in the cerebral cortical and subcortical regions in cats. In these studies D and L isomers of amphetamine are used to induce a chemical brain state changes. The AEP are selected in the amphetamine altered states based on the prestimulus auto spectra.

Analog-Digital Conversion↗
PubMed1989

Directionality of neural signals in central nervous system neural networks.

These studies are concerned with neuronal population theory of brain function. Neural networks the cerebral cortex and the limbic systems are investigated. We use coherence, partial coherence, phase and cycle time spectral analysis in these studies. The development of software for phase filtering has permitted us to analyze directionality of neural signal flow following coherence and partial coherence estimates. These estimates give an indication of the interaction between the brain regions studied. These data give further insights of the input and output status and the linear aspects of these interactions. Spontaneous and evoked potential analog data are analyzed to evaluate the physiological parameters of these interrelations.

Amygdala↗
PubMed1981

Ketamine-acepromazine as an anaesthetic agent for chinchillas (Chinchilla laniger).

Intramuscular injections of ketamine-acepromazine provided satisfactory surgical levels of anaesthesia. Induction was smooth. There was a wide margin of safety with no significant side effects, and there were no deaths attributable to anaesthesia. Induction time was 4-6 min, duration of surgical anaesthesia was 40-60 min, with complete recovery in 2-5 h. 80 chinchillas were used for this study.

Acepromazine↗
PubMed1976

Development of telemetric techniques for use in studies of the electrical activity of the brain.

A telemetry system has been designed to transmit two channels of wideband activity (0.2 Hz-2.5 KHz) recorded from high-impedance microelectrodes in the brains of free-moving cats. Thus, both unit activity and slow-wave field activity are accessible without disruption of the animals' behavior. In addition, circuitry is described that conditions the receiver signals, that dicriminates valid subcarrier signals from receiver noise and that automatically aborts data output in the absence of discriminable subcarrier. This receiver signal processing circuitry thus assures the fidelity of the decoded subcarrier, greatly facilitates further machine processing of the data and frees the experimenter from having to continuously monitor the receiver signals to subjectively edit out noisy data.

Animals↗