Effects Of Different Anesthetics Research Articles

Chronic brain unit recording for pharmacological applications

A technique is described in detail for chronic unit recording in awake, unrestrained animals during pharmacological manipulation. An example of the use of the technique is given with pharmacologically identified cells, behavioral tremor and how they are affected by anesthetics. The technique involves implantation of Nichrome wire electrodes into brain areas and anchoring them in an array on the skull. For recording, the electrode connectors on the skull are plugged into a light-weight field effect transistor (FET) amplifier the design of which is detailed. The FET amplifier is attached to a cable suspended from a counter-balanced commutator arm above the subject. This system allows subjects to move freely while unit activity from well isolated neurons or small groups of neurons is recorded. The technique allows long-term recording from the area of the electrodes over several weeks. Recording data obtained after harmaline injections and the slowing effects of different anesthetics on the rate of firing of units is presented.

Effect of halothane and pentobarbital anesthesia on the dispersion of indicator particles passing through the central circulation of the dog.

To investigate the effect of different anesthetics on the flow properties of the central circulation, curves were obtained by the multiple indocyanine-green indicator-dilution technic from 7 dogs anesthetized with halothane or pentobarbital. The width of the curve provided a measure of the dispersion of indicator particles during passage through the central circulation. The vascular resistance of the animals was altered by the administration of methoxamine and sodium nitroprusside. The authors found that dispersion in the central circulation is linearly related to the total peripheral resistance (TPR). For any value of TPR, the amount of dispersion of indicator particles passing through the central circulation was greater with halothane plus pentobarbital anesthesia than with pentobarbital only. The study indicates that the type of anesthesia influences the dispersion of indicator particles passing through the central circulation. A better under standing of this process will be helpful in interpreting the results of indicator-dilution cardiac-output determinations performed in persons under general anesthesia.

Differential effects of anesthetics on neutral proteinase activity of rat brain regions according to time of day

Microfluorometry of trypsin-like neutral proteinase activity in hypothalamus, head of caudate nucleus and occipital cerebral cortex of adult male rats was applied in a study on the effects of ether, Nembutal, anoxia in CO 2 and confinement without anesthesia at two times of the day. Anesthesia starting 3 h after the daily start of light and with either ether or Nembutal caused significant increases in neutral proteinase activity in all three regions, but differing in degree and course of increase according to region. Ether anesthesia 5 h later led to a decrease in neutral proteinase activity. These effects are not likely to be due to changes in tissue levels of neutral proteinase inhibitor. The possible mechanisms and bases of these effects were discussed. The utility of the differences according to time of day of the responses of the brain tissue neutral proteinase system to anesthetics was discussed in relation to functional systems in which brain neutral proteinases have been thought to have a role.

Neurophysiological effects of different anesthetics in conscious man.

ARTICLESNeurophysiological effects of different anesthetics in conscious manE. C. Hosick, D. L. Clark, N. Adam, and B. S. RosnerE. C. Hosick, D. L. Clark, N. Adam, and B. S. RosnerPublished Online:01 Dec 1971https://doi.org/10.1152/jappl.1971.31.6.892MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation More from this issue > Volume 31Issue 6December 1971Pages 892-898 Copyright & PermissionsCopyright © 1971 the American Physiological Societyhttps://doi.org/10.1152/jappl.1971.31.6.892PubMed5123670History Published online 1 December 1971 Published in print 1 December 1971 Metrics

Neurophysiological effects of different anesthetics in unconscious man.

Neurophysiological effects of different anesthetics in unconscious man.

Differential effects of anesthetics on mesencephalic reticular neurons. I. Spontaneous firing patterns.

Differential effects of anesthetics on mesencephalic reticular neurons. I. Spontaneous firing patterns.

Differential effects of anesthetics on mesencephalic reticular neurons. II. Responses to repetitive somatosensory electrical stimulation.

Differential effects of anesthetics on mesencephalic reticular neurons. II. Responses to repetitive somatosensory electrical stimulation.

BALLISTOCARDIOGRAPHIC EXPERIMENTS INTO SOME PROBLEMS OF ANAESTHESIA

SUMMARY The theory and application of the quantitative ballistocardiograph is described using the method of Klensch. It is possible to use this method for determining the stroke volume of the heart during anaesthesia simply and rapidly without affecting the circulation. Evidence was obtained showing that halothane may cause direct myocardial depression in some patients. Despite reduction in circulatory resistance a reduction in beart output was observed more frequently than expected. It was demonstrated also that the behaviour of the peripheral circulatory resistance is an important factor in determining stroke volume and results of measurements under the effect of different anaesthetics, ganglionic blockers and vasoconstrictors are presented.

A Study of the Effect of Different Anesthetics On The Electrical Potential of the Brain Cortex.*

A Study of the Effect of Different Anesthetics On The Electrical Potential of the Brain Cortex.*

ANALYSIS OF FORM REGULATION WITH THE AID OF ANÆSTHETICS

During the last year and a half the writer has carried on an extensive series of experiments on the influence of certain anaesthetics on the course and results of form regulation in Planaria dorotocephala Woodworth. Since the method has proved to be of considerable value and since it will be some time before the results of these and other experiments planned for the future can be presented in full, it seems desirable to present briefly and without extended comment the most important features of the work up to date as an illustration of the value of the method and the results to be attained by it. In my experiments thus far I have used chiefly alcohol, ether and acetone-chloroform, known commercially as chloretone. Although alcohol is much less strongly anaesthetic than many other substances its action is in general similar in kind to that of the substances commonly known as anaesthetics. The results with the three substances mentioned are practically identical so far as the more general features are concerned, though various differences of detail appear, which need not be considered here. Incidentally, however, it may be noted that these differences in the effects of the different anaesthetics serve to some extent as a means of determining the specific differences in the effects of different anaesthetics on the metabolic processes: how far they will prove to be of value in this direction only the future can determine.