Effect of pentobarbital and ether on the spreading cortical depression.
نویسندگان
چکیده
WEAK electrical stimulus applied to A the rabbit’s cerebral cortex causes under certain conditions (I) a depression of the spontaneous electrical activity which spreads with low velocity (3-5 mm/min) over the cortex and lasts from I to 3 min. Several repetitions of the stimulus at intervals of 8-10 min may change this spreading cortical depression into a spreading convulsive pattern (2-5). Both the spreading depression and the spreading convulsive pattern are accompanied by a slow potential change of the cortex (I, 5-S). The cortical surface first turns negative with respect to an indifferent electrode; then the polarity is reversed and the cortex becomes positive. The magnitude of the negative phase of the slow potential is often IO mv or more, while the positive phase is usually smaller. In some instances the negative phase is preceded by a small galvanometer deflection indicating cortical positivity. The total duration of this slow potential change may be 3 min or more. It was shown that the slow potential change travels over the cortex at the same velocity as the depression, preceding the latter by 10-40 set (I). Leao (2) found that Dial and pentobarbital in moderate doses, and light ether narcosis do not abolish the spreading depression. Also moderate doses of pentobarbital (up to 30 mg/kg body weight) do not prevent the convulsive patterns which may replace the depression (9). Barbiturates and volatile narcotics are known to act differently on both the electrocorticogram and the polarization state of nervous tissue (see DISCUSSION). It seemed therefore of interest to investigate more fully the effects of ether and pentobarbital, as representatives of these groups of narcotics,
منابع مشابه
Effect of Pentobarbital and Ether on the Spreading Cortical Depression’
WEAK electrical stimulus applied to A the rabbit’s cerebral cortex causes under certain conditions (I) a depression of the spontaneous electrical activity which spreads with low velocity (3-5 mm/min) over the cortex and lasts from I to 3 min. Several repetitions of the stimulus at intervals of 8-10 min may change this spreading cortical depression into a spreading convulsive pattern (2-5). Both...
متن کاملPossible mechanism of tolerance to ketamine-induced blockade of cortical spreading depression
Ketamine (KET) induced blockade of cortical spreading depression (CSD) declines with repeated KET applications in a way suggesting the development of tolerance. Possible mechanism of this process was studied in 31 rats anestheized with pentobarbital. CSD was elicited by injection of 1µl of 5% KCl into cortex at 15 min intervals and monitored by recording the accompanying slow potential waves....
متن کاملThe Neuroprotective Effects of Long-Term Repetitive Transcranial Magnetic Stimulation on the Cortical Spreading Depression-induced Damages in Rat’s Brain
Introduction: Cortical Spreading Depression (CSD) is a propagating wave of neural and glial cell depolarization with important role in several clinical disorders. Repetitive Transcranial Magnetic Stimulation (rTMS) is a potential tool with preventive treatment effects in psychiatric and neuronal disorders. In this paper, we study the effects of rTMS on CSD by using behavioral and histological a...
متن کاملEffect of Cannabinoid Receptor Activation on Spreading Depression
Objective(s) The objective of this study was to evaluate the effect of cannabinoid on cortical spreading depression (CSD) in rat brain. Cannabis has been used for centuries for both symptomatic and prophylactic treatment of different types of headaches including migraine. CSD is believed to be a putative neuronal mechanism underlying migraine aura and subsequent pain. Materials and Methods T...
متن کاملنقش مهار منتشر شونده قشری بر القای تشنج در هیپوکمپ موش صحرایی نر
Background & Aims : Spreading depression is a pathophysiological phenomenon that is initiated by a self-propagating depolarization wave with a short-term excitability and is followed immediately by an inhibitory phase and then continues with a long-term secondary excitability. Spreading depression has a critical role in many disorders such as migraine and seizures . The purpose of this stud...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The American journal of physiology
دوره 173 1 شماره
صفحات -
تاریخ انتشار 1953