EFFECTS OF SECTION OF THE CORPUS CALLOSUM ON DECOMPRESSION HYPOXIA AND ON PENTYLENETETRAZOL (METRAZOL) CONVULSIONS

1962 ◽  
Vol 40 (11) ◽  
pp. 1477-1491 ◽  
Author(s):  
S. J. Manax ◽  
G. W. Stavraky
Keyword(s):  
Corpus Callosum ◽  
Experimental Conditions ◽  
S Waves ◽  
Implanted Electrodes ◽  
White Rats ◽  
Wave Patterns ◽  
Metrazol Convulsions ◽  
Eeg Changes ◽  
The Brain ◽  
Eeg Pattern

Electroencephalographic studies were carried out in white rats with chronically implanted electrodes located on the skull over the frontal areas of the brain, with the animals suspended in a sling in a decompression chamber. Exposed to simulated elevated altitude at weekly intervals 4 to 6 months after section of the corpus callosum 26 animals revealed a greater sensitivity to hypoxia than 22 controls. This was shown by a lower threshold of convulsibility and by a longer duration of the convulsions. Under the experimental conditions employed the electrocortical activity in control animals consisted of 1.5–3 c/s and 4–6 c/s waves of up to 40-μv amplitude with 11–14 c/s waves superimposed. In the corpus-callotomized rats the activity was somewhat slower and of a higher amplitude, this being more apparent [Formula: see text] months after the operation than at the time of the decompression experiments. Decompression of both groups of animals resulted in characteristic EEG changes culminating in the appearance of hypoxic preconvulsive potentials of high voltage (60–180 μv) and slow frequency (1.5–3 c/s) which were first grouped in paroxysms of about 3 to 5 seconds' duration, later becoming continuous. When decompression was continued, this activity was followed by convulsive discharges, all of the manifestations being more pronounced and recurring at lower altitudes in the corpus-callotomized animals than in the controls. An analysis of the wave patterns in 28 sacrifice experiments with transection of the spinal cord and curarization of the animals showed that the observed EEG activity did not depend on motor components.The EEG patterns during the excitatory stages of hypoxia or asphyxia resembled closely certain phases of pentylenetetrazol-induced activity; however, at the height of the convulsive EEG pattern induced by pentylenetetrazol, periods of asphyxia disorganized the spike activity caused by this agent and markedly depressed the EEG.

EFFECTS OF SECTION OF THE CORPUS CALLOSUM ON DECOMPRESSION HYPOXIA AND ON PENTYLENETETRAZOL (METRAZOL) CONVULSIONS

1962 ◽  
Vol 40 (1) ◽  
pp. 1477-1491
Author(s):  
S. J. Manax ◽  
G. W. Stavraky
Keyword(s):  
Corpus Callosum ◽  
Experimental Conditions ◽  
S Waves ◽  
Implanted Electrodes ◽  
White Rats ◽  
Wave Patterns ◽  
Metrazol Convulsions ◽  
Eeg Changes ◽  
The Brain ◽  
Eeg Pattern

Electroencephalographic studies were carried out in white rats with chronically implanted electrodes located on the skull over the frontal areas of the brain, with the animals suspended in a sling in a decompression chamber. Exposed to simulated elevated altitude at weekly intervals 4 to 6 months after section of the corpus callosum 26 animals revealed a greater sensitivity to hypoxia than 22 controls. This was shown by a lower threshold of convulsibility and by a longer duration of the convulsions. Under the experimental conditions employed the electrocortical activity in control animals consisted of 1.5–3 c/s and 4–6 c/s waves of up to 40-μv amplitude with 11–14 c/s waves superimposed. In the corpus-callotomized rats the activity was somewhat slower and of a higher amplitude, this being more apparent [Formula: see text] months after the operation than at the time of the decompression experiments. Decompression of both groups of animals resulted in characteristic EEG changes culminating in the appearance of hypoxic preconvulsive potentials of high voltage (60–180 μv) and slow frequency (1.5–3 c/s) which were first grouped in paroxysms of about 3 to 5 seconds' duration, later becoming continuous. When decompression was continued, this activity was followed by convulsive discharges, all of the manifestations being more pronounced and recurring at lower altitudes in the corpus-callotomized animals than in the controls. An analysis of the wave patterns in 28 sacrifice experiments with transection of the spinal cord and curarization of the animals showed that the observed EEG activity did not depend on motor components.The EEG patterns during the excitatory stages of hypoxia or asphyxia resembled closely certain phases of pentylenetetrazol-induced activity; however, at the height of the convulsive EEG pattern induced by pentylenetetrazol, periods of asphyxia disorganized the spike activity caused by this agent and markedly depressed the EEG.

FURTHER STUDIES ON DIFFERENCES IN THE UPTAKE OF 131I-TRIIODOTHYRONINE IN THE BRAINS OF MALE AND FEMALE RATS

1964 ◽  
Vol 45 (2) ◽  
pp. 219-236 ◽  
Author(s):  
Donald H. Ford ◽  
Marvin Hartstein ◽  
Ralph Rhines
Keyword(s):  
Sex Difference ◽  
Degradation Rate ◽  
Enterohepatic Circulation ◽  
Cell Uptake ◽  
Female Rats ◽  
Experimental Conditions ◽  
Male And Female ◽  
White Rats ◽  
Male And Female Rats ◽  
The Brain

ABSTRACT A sex difference in the uptake of T3–131I by the brain has been previously noted in white rats such that higher uptakes were routinely observed in females. It was believed that such differences in T3–131I uptake might be related to the conjugation of T3–131I to glucuronic acid, to the clearance rate of T3–131I by the liver, to a difference in the iodinated derivatives entering the blood from the liver or to the breakdown of the T3-glucuronide complex within the intestine. Investigation of these components of the enterohepatic metabolism of triiodothyronine in male and female rats revealed that there were no real sex differences at this point. Studies on the effect of testosterone propionate (TP) given either to adult or to newborn females suggest a direct effect of TP on the degradation of T3–131I. Thus, the CNS uptake of T3–131I in TP-treated adult females was reduced and more like that observed in males and the point at which the degradation rate exceeded the uptake rate occurred sooner. The effect of TP in the newborn androgen sterilized females was manifest only in the red blood cell uptake of T3, which was decreased and therefore more like that seen in males than in untreated females. It thus appears that the lower uptake of T3–131I by the male CNS is due in part at least to a higher degradation rate which decreases the amount of labeled T3 available for concentration in the brain more quickly than in the female. The female, on the other hand, has a higher plasma and RBC T3–131I level, which is apparently related to the somewhat slower degradation rate of the injected labeled hormone. From previous experiments, one might anticipate that such an elevation in available T3–131I would be associated with a slight increase in T3 uptake by nervous tissue. This was substantially what was observed. Thus, the sex difference in T3–131I uptake by the CNS of the white rat appears to be somewhat related to the intrinsic degradation rate of the injected hormone by the tissues, particularly as influenced by androgens. Other factors involving the enterohepatic circulation and metabolism of T3 may be involved, but only perhaps as influenced along with other tissues by androgens. Certainly no evidence for any sex difference in this very important area of thyroid hormone metabolism was observed under any of the experimental conditions studied here.

Effect of combined citicoline and glutamate antibodies on acute, generalized convusions induced by pentylenetetrazole in mice

2018 ◽  
pp. 24-29
Author(s):  
М.Н. Карпова ◽  
Л.В. Кузнецова ◽  
Н.Ю. Клишина ◽  
Л.А. Ветрилэ
Keyword(s):  
Drug Combination ◽  
Subcutaneous Injection ◽  
Seizure Activity ◽  
Experimental Conditions ◽  
Slow Progression ◽  
Experiment Control ◽  
Effective Doses ◽  
Experimental Justification ◽  
Series Of Experiments ◽  
The Brain

Цель исследования. На 2 моделях острых генерализованных судорог (ОГС), вызванных конвульсантом пентилентетразолом (ПТЗ), изучить эффективность сочетанного применения ноотропа цитиколина - препарата с противосудорожным действием, нейрорегенеративной, нейропротекторной активностью и антител (АТ) к глутамату, обладающих противосудорожной активностью. Методика. Эксперименты выполнены на мышах-самцах линии C57Bl/6 (n = 87) массой 22-28 г. Эффективность сочетанного применения цитиколина и АТ к глутамату изучали на двух моделях ОГС. Выполнено 2 серии экспериментов. В 1-й серии ОГС вызывали внутривенным введением 1% раствора ПТЗ со скоростью 0,01 мл/с. Для изучения эффективности сочетанного применения препаратов определяли минимальное противосудорожное действие цитиколина (Цераксон, «Nicomed Ferrer Internaсional, S.A.») и АТ к глутамату при их внутрибрюшинном введении. С этой целью цитиколин вводили в дозах 500 и 300 мг/кг за 1 ч до введения ПТЗ, АТ к глутамату - в дозах 5 и 2,5 мг/кг за 1 ч 30 мин до введения ПТЗ. АТ к глутамату получали путем гипериммунизации кроликов соответствующим конъюгированным антигеном. Во 2-й серии ОГС вызывали подкожным введением ПТЗ в дозе 85 мг/кг. Для изучения эффективности сочетанного действия изучаемых препаратов последние вводили в минимально действующих дозах, установленных в 1-й серии экспериментов. Контролем во всех сериях опытов служили животные, которым вводили в аналогичных условиях и в том же объеме физиологический раствор. Результаты. Показано, что сочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах (300 и 2,5 мг/кг соответственно) при моделировании ОГС не вызывало повышения судорожной активности мозга и усиления противосудорожных свойств препаратов. Заключение. Cочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах не вызывало повышения судорожной активности мозга, что свидетельствует о безопасности совместного применения препаратов. Проведенное исследование может служить также экспериментальным обоснованием возможности использования сочетанного применения данных препаратов при судорогах с целью замедления прогрессирования нейродегенеративных процессов и благоприятного влияния на когнитивные функции. Aim. To study the effectivity of a combination of citicoline, a nootropic substance with neuroregenerative, neuroprotective, and anticonvulsant actions, and glutamate antibodies (АB) with an anticonvulsant action in two models of acute generalized convulsions (AGC) caused by the convulsant pentylenetetrazole (PTZ). Methods. Experiments were conducted on C57Bl/6 mice (n = 87) weighing 22-28 g. Effects of combined citicoline and glutamate АB were studied on two models of AGС. In the first series of experiments, AGС was induced by intravenous infusion of a 1% PTZ solution at 0.01 ml/sec. In the second series, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate efficacy of the drug combination minimum intraperitoneal anticonvulsant doses of citicoline (Tserakson, Nicomed Ferrer Internacional, S.A.) and glutamate АB were determined. To this purpose, citicoline was administered at 500 and 300 mg/kg 1 h prior to PTZ, and glutamate АB was administered at 5 and 2.5 mg/kg 90 min prior to PTZ. Glutamate АB was obtained by hyperimmunization of rabbits with a respective conjugated antigen. In the second series of experiments, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate the effect of the drug combination, the drugs were administered at the minimum effective doses determined in the first series of experiment. Control animals were injected with the same volume of saline in the same experimental conditions. Results. The combination of citicoline and glutamate AB used at minimum effective doses of 300 and 2.5 mg/kg, respectively, did not increase the seizure activity in the brain and enhanced anticonvulsant properties of the drugs in two models of AGС. Conclusion. The combination of citicoline and glutamate AT at minimum effective doses did not increase the convulsive activity in the brain, which supported safety of the drug combination. Besides, this study can serve as an experimental justification for using the drug combination in convulsions to favorably influence cognitive functions and slow progression of neurodegenerative processes.

Regional blood flow in the brain and spinal cord of hypothermic rats

1989 ◽  
Vol 257 (3) ◽  
pp. H785-H790
Author(s):  
T. Sakamoto ◽  
W. W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Brain Stem ◽  
Regional Blood Flow ◽  
Experimental Conditions ◽  
Pentobarbital Sodium ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
The Brain

[14C]butanol tissue uptake was used to measure simultaneously regional blood flow in three regions of the brain (cerebral and cerebellar hemispheres and brain stem) and in five levels of the spinal cord in 10 normothermic rats (group A) and in 10 rats in which rectal temperature had been lowered to 27.7 +/- 0.3 degrees C by applying ice to the torso (group B). Pentobarbital sodium anesthesia was used. Mean arterial blood pressure varied minimally between groups as did arterial pH, PO2, and PCO2. In group A, regional spinal cord blood flow (rSCBF) varied from 49.7 +/- 1.6 to 62.6 +/- 2.1 ml.min-1.100 g-1; in brain, regional blood flow (rBBF) averaged 74.4 +/- 2.3 ml.min-1.100 g-1 in the whole brain and was highest in the brain stem. rSCBF in group B was elevated in all levels of the cord by 21-34% (P less than 0.05). rBBF, however, was lowered by 21% in the cerebral hemispheres (P less than 0.001) and by 14% in the brain as a whole (P less than 0.05). The changes in calculated vascular resistance tended to be inversely related to blood flow in all tissues. We conclude that rBBF is depressed in acutely hypothermic pentobarbital sodium-anesthetized rats, as has been noted before, but that rSCBF rises under these experimental conditions. The elevation of rSCBF in hypothermic rats confirms our previous observations.

THE METABOLISM OF NORMAL BRAIN AND HUMAN GLIOMAS IN RELATION TO CELL TYPE AND DENSITY

1955 ◽  
Vol 33 (3) ◽  
pp. 395-403 ◽  
Author(s):  
Irving H. Heller ◽  
K. A. C. Elliott
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Brain Tumors ◽  
Corpus Callosum ◽  
Oxygen Uptake ◽  
Glial Cells ◽  
Cerebellar Cortex ◽  
Unit Weight ◽  
Uptake Rates ◽  
The Brain

Per unit weight, cerebral and cerebellar cortex respire much more actively than corpus callosum. The rate per cell nucleus is highest in cerebral cortex, lower in corpus callosum, and still lower in cerebellar cortex. The oxygen uptake rates of the brain tumors studied, with the exception of an oligodendroglioma, were about the same as that of white matter on the weight basis but lower than that of cerebral cortex or white matter on the cell basis. In agreement with previous work, an oligodendroglioma respired much more actively than the other tumors. The rates of glycolysis of the brain tumors per unit weight were low but, relative to their respiration rate, glycolysis was higher than in normal gray or white matter. Consideration of the figures obtained leads to the following tentative conclusions: Glial cells of corpus callosum respire more actively than the neurons of the cerebellar cortex. Neurons of the cerebral cortex respire on the average much more actively than neurons of the cerebellar cortex or glial cells. Considerably more than 70% of the oxygen uptake by cerebral cortex is due to neurons. The oxygen uptake rates of normal oligodendroglia and astrocytes are probably about the same as the rates found per nucleus in an oligodendroglioma and in astrocytomas; oligodendroglia respire much more actively than astrocytes.

Brain shift: an error factor during implantation of deep brain stimulation electrodes

2007 ◽  
Vol 107 (5) ◽  
pp. 989-997 ◽  
Author(s):  
Yasushi Miyagi ◽  
Fumio Shima ◽  
Tomio Sasaki
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Brain Shift ◽  
Mr Images ◽  
Implanted Electrodes ◽  
Error Factor ◽  
Bilateral Surgery ◽  
Second Procedure ◽  
The Brain ◽  
Deep Brain

Object The goal of this study was to focus on the tendency of brain shift during stereotactic neurosurgery and the shift's impact on the unilateral and bilateral implantation of electrodes for deep brain stimulation (DBS). Methods Eight unilateral and 10 bilateral DBS electrodes at 10 nuclei ventrales intermedii and 18 subthalamic nuclei were implanted in patients at Kaizuka Hospital with the aid of magnetic resonance (MR) imaging–guided and microelectrode-guided methods. Brain shift was assessed as changes in the 3D coordinates of the anterior and posterior commissures (AC and PC) with MR images before and immediately after the implantation surgery. The positions of the implanted electrodes, based on the midcommissural point and AC–PC line, were measured both on x-ray films (virtual position) during surgery and the postoperative MR images (actual position) obtained on the 7th day postoperatively. Results Contralateral and posterior shift of the AC and PC were the characteristics of unilateral and bilateral procedures, respectively. The authors suggest the following. 1) The first unilateral procedure elicits a unilateral air invasion, resulting in a contralateral brain shift. 2) During the second procedure in the bilateral surgery, the contralateral shift is reset to the midline and, at the same time, the anteroposterior support by the contralateral hemisphere against gravity is lost due to a bilateral air invasion, resulting in a significant posterior (caudal) shift. Conclusions To note the tendency of the brain to shift is very important for accurate implantation of a DBS electrode or high frequency thermocoagulation, as well as for the prediction of therapeutic and adverse effects of stereotactic surgery.

scholarly journals Migraine with Prolonged Aura: Correlation of Clinical and EEG Features

1995 ◽  
Vol 8 (2) ◽  
pp. 109-114 ◽  
Author(s):  
A. O. Ogunyemi
Keyword(s):  
Cerebral Cortex ◽  
Migraine With Aura ◽  
Slow Waves ◽  
Spreading Cortical Depression ◽  
Eeg Abnormalities ◽  
Cortical Depression ◽  
Eeg Changes ◽  
Eeg Recordings ◽  
The Brain

Migraine with prolonged aura has rarely been examined with regard to the sequence of the neurological symptoms and the associated EEG changes. This report describes five patients who underwent clinical assessment and EEG recordings during attacks of migraine with prolonged aura. CT scan of the brain was obtained in four of them. Follow-up EEG was also obtained. The aura symptoms either preceded the headache or were coincident with it. The aura symptoms evolved in a manner consistent with posterior-to-anterior dysfunction of the cerebral cortex. The EEG abnormalities were non-epileptiform and consisted of focal delta slow waves or theta slow waves. The EEG abnormalities showed good correlation with the patients' aura symptoms and resolved when the patients became symptom free. The posterior-to-anterior sequence of the aura symptoms is in accord with the findings during cerebral blood flow studies in patients having migraine with aura. Also the symptoms and EEG changes in our patients indicate dysfunction of the cerebral cortex, consistent with the notion that spreading cortical depression may be the underlying pathophysiological event in migraine with aura.

scholarly journals Atypical EEG pattern in children with absence seizures

1995 ◽  
Vol 53 (2) ◽  
pp. 258-261 ◽  
Author(s):  
Délrio F. Silva ◽  
Márcia Marques Lima ◽  
Renato Anghinah ◽  
Edmar Zanoteli ◽  
José Geraldo Camargo Lima
Keyword(s):  
Absence Seizure ◽  
Complete Control ◽  
Absence Seizures ◽  
Normal Finding ◽  
Delta Activity ◽  
Eeg Changes ◽  
Eeg Pattern

We studied four children with diagnosis of absence seizures (generalized primary epilepsy), and with a generalized delta activity on the EEG during clinical attacks provoked by hyperventilation. The lack of ictal generalized spike-and-wave discharges with a frequency of 3 Hz in our patients, makes this an atypical pattern. All children had complete control of their seizures and disappearance of the EEG changes with valproate. We concluded that generalized delta activity observed on EEG during the hyperventilation in children should not always be considered as a normal finding for age, since it could be an ictal event of an absence seizure.

scholarly journals Non-local means based Rician noise filtering for diffusion tensor and kurtosis imaging in human brain and spinal cord

2020 ◽  
Author(s):  
Zhongping Zhang ◽  
Dhanashree Vernekar ◽  
Wenshu Qian ◽  
Mina Kim
Keyword(s):  
Spinal Cord ◽  
Corpus Callosum ◽  
Human Brain ◽  
Healthy Subjects ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Chi Square ◽  
Lateral Column ◽  
Diffusion Weighted Images ◽  
The Brain

Abstract Background: To investigate the effect of using an Rician nonlocal means (NLM) filter on quantification of diffusion tensor (DT)- and diffusion kurtosis (DK)-derived metrics in various anatomical regions of the human brain and the spinal cord, when combined with a constrained linear least squares (CLLS) approach.Methods: Prospective brain data from 9 healthy subjects and retrospective spinal cord data from 5 healthy subjects from a 3T MRI scanner were included in the study. Prior to tensor estimation, registered diffusion weighted images were denoised by an optimized blockwise NLM filter with CLLS. Mean kurtosis (MK), radial kurtosis (RK), axial kurtosis (AK), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD) and fractional anisotropy (FA), were determined in anatomical structures of the brain and the spinal cord. DTI and DKI metrics, signal-to-noise ratio (SNR) and Chi-square values were quantified in distinct anatomical regions for all subjects, with and without Rician denoising. Results: The averaged SNR significantly increased with Rician denoising by a factor of 2 while the averaged Chi-square values significantly decreased up to 61 % in the brain and up to 43% in the spinal cord after Rician NLM filtering. In the brain, the mean MK varied from 0.70 (putamen) to 1.27 (internal capsule) while AK and RK varied from 0.58 (corpus callosum) to 0.92 (cingulum) and from 0.70 (putamen) to 1.98 (corpus callosum), respectively. In the spinal cord, FA varied from 0.78 in lateral column to 0.81 in dorsal column while MD varied from 0.91 × 10−3 mm2/s (lateral) to 0.93 × 10−3 mm2/s (dorsal). RD varied from 0.34 × 10−3 mm2/s (dorsal) to 0.38 × 10−3 mm2/s (lateral) and AD varied from 1.96 × 10−3 mm2/s (lateral) to 2.11 × 10−3 mm2/s (dorsal).Conclusions: Our results show Rician denoising NLM filter incorporated with CLLS significantly increases SNR and reduces estimation errors of DT- and KT-derived metrics, providing the reliable metrics estimation with adequate SNR levels.

scholarly journals A higher proportion of ermin-immunopositive oligodendrocytes in areas of remyelination

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256155
Author(s):  
Intakhar Ahmad ◽  
Stig Wergeland ◽  
Eystein Oveland ◽  
Lars Bø
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Corpus Callosum ◽  
Mouse Model ◽  
Grey Matter ◽  
Early Stage ◽  
Relative Proportion ◽  
Normal Appearing White Matter ◽  
The Brain

Incomplete remyelination is frequent in multiple sclerosis (MS)-lesions, but there is no established marker for recent remyelination. We investigated the role of the oligodendrocyte/myelin protein ermin in de- and remyelination in the cuprizone (CPZ) mouse model, and in MS. The density of ermin+ oligodendrocytes in the brain was significantly decreased after one week of CPZ exposure (p < 0.02). The relative proportion of ermin+ cells compared to cells positive for the late-stage oligodendrocyte marker Nogo-A increased at the onset of remyelination in the corpus callosum (p < 0.02). The density of ermin-positive cells increased in the corpus callosum during the CPZ-phase of extensive remyelination (p < 0.0001). In MS, the density of ermin+ cells was higher in remyelinated lesion areas compared to non-remyelinated areas both in white- (p < 0.0001) and grey matter (p < 0.0001) and compared to normal-appearing white matter (p < 0.001). Ermin immunopositive cells in MS-lesions were not immunopositive for the early-stage oligodendrocyte markers O4 and O1, but a subpopulation was immunopositive for Nogo-A. The data suggest a relatively higher proportion of ermin immunopositivity in oligodendrocytes compared to Nogo-A indicates recent or ongoing remyelination.

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