scholarly journals Epithelial Conduction in Hydromedusae

1968 ◽  
Vol 52 (3) ◽  
pp. 600-621 ◽  
Author(s):  
G. O. Mackie ◽  
L. M. Passano
Keyword(s):  
Nervous System ◽  
Spontaneous Activity ◽  
Nervous Activity ◽  
The Other ◽  
Refractory Periods ◽  
Spread Of Excitation ◽  
Composite Events ◽  
Waves Propagation ◽  
Excess Mg ◽  
Electrical Stimuli

Sarsia, Euphysa, and other hydromedusae have been studied by electrophysiological techniques and are found to have nonnervous conducting epithelia resembling those described earlier for siphonophores. Simple, nonmuscular epithelia fire singly or repetitively following brief electrical stimuli. The pulses recorded with suction electrodes are biphasic, initially positive, and show amplitudes of 0.75–2.0 mv, durations of 5–15 msec, and velocities of 15–35 cm/sec with short refractory periods. In the swimming muscle (myoepithelium) 2.0–4.0 mv composite events lasting 150–300 msec are associated with contraction waves. Propagation in nonnervous epithelia is typically all-or-none, nondecremental, and unpolarized. The subumbrellar endoderm lamella conducts independently of the adjacent ectoderm. The lower regions of the tentacles do not show propagated epithelial events. The spread of excitation in conducting epithelia and associated effector responses are described. Examples are given of interaction between events seemingly conducted in the nervous system and those in nonnervous epithelia. Either system may excite the other. Spontaneous activity, however, appears to originate in the nervous system. Conduction in nonnervous tissues is unaffected by excess Mg++ in concentrations suppressing presumed nervous activity, although this may not be a wholly adequate criterion for distinguishing components of the two systems. Evidence from old work by Romanes is considered in the light of these findings and the general significance of epithelial conduction is discussed.

scholarly journals Epithelial Conduction in Hydromedusae

1968 ◽  
Vol 52 (4) ◽  
pp. 600-621 ◽  
Author(s):  
G. O. Mackie ◽  
L. M. Passano
Keyword(s):  
Nervous System ◽  
Spontaneous Activity ◽  
Nervous Activity ◽  
The Other ◽  
Refractory Periods ◽  
Spread Of Excitation ◽  
Composite Events ◽  
Waves Propagation ◽  
Excess Mg ◽  
Electrical Stimuli

Sarsia, Euphysa, and other hydromedusae have been studied by electrophysiological techniques and are found to have nonnervous conducting epithelia resembling those described earlier for siphonophores. Simple, non-muscular epithelia fire singly or repetitively following brief electrical stimuli. The pulses recorded with suction electrodes are biphasic, initially positive, and show amplitudes of 0.75–2.0 mv, durations of 5–15 msec, and velocities of 15–35 cm/sec with short refractory periods. In the swimming muscle (myoepithelium) 2.0–4.0 mv composite events lasting 150–300 msec are associated with contraction waves. Propagation in nonnervous epithelia is typically all-or-none, nondecremental, and unpolarized. The subumbrellar endoderm lamella conducts independently of the adjacent ectoderm. The lower regions of the tentacles do not show propagated epithelial events. The spread of excitation in conducting epithelia and associated effector responses are described. Examples are given of interaction between events seemingly conducted in the nervous system and those in nonnervous epithelia. Either system may excite the other. Spontaneous activity, however, appears to originate in the nervous system. Conduction in nonnervous tissues is unaffected by excess Mg++ in concentrations suppressing presumed nervous activity, although this may not be a wholly adequate criterion for distinguishing components of the two systems. Evidence from old work by Romanes is considered in the light of these findings and the general significance of epithelial conduction is discussed.

scholarly journals Psycho-Electrophysiological Benefits of Forest Therapies Focused on Qigong and Walking with Elderly Individuals

2021 ◽  
Vol 18 (6) ◽  
pp. 3004
Author(s):  
Jiyune Yi ◽  
Seul Gee Kim ◽  
Taegyu Khil ◽  
Minja Shin ◽  
Jin-Hee You ◽  
...  
Keyword(s):  
Urban Forest ◽  
Nervous Activity ◽  
Health Problems ◽  
The Other ◽  
Upper Body ◽  
Sympathetic Nervous Activity ◽  
Control Group ◽  
Beta Band ◽  
Elderly Individuals ◽  
Beneficial Effects

We developed two distinct forest therapy programs (FTPs) and compared their effects on dementia prevention and related health problems for older adults. One was focused on Qigong practice in the forest (QP) and the other involved active walking in the forest (WP). Both FTPs consisted of twelve 2-h sessions over six weeks and were conducted in an urban forest. We obtained data from 25, 18, and 26 participants aged 65 years or above for the QP, WP, and control groups, respectively. Neuropsychological scores via cognition (MoCA), geriatric depression (GDS) and quality of life (EQ-5D), and electrophysiological variables (electroencephalography, bioimpedance, and heart rate variability) were measured. We analyzed the intervention effects with a generalized linear model. Compared to the control group, the WP group showed benefits in terms of neurocognition (increases in the MoCA score, and alpha and beta band power values in the electroencephalogram), sympathetic nervous activity, and bioimpedance in the lower body. On the other hand, the QP group showed alleviated depression and an increased bioimpedance phase angle in the upper body. In conclusion, both active walking and Qigong in the forest were shown to have distinctive neuropsychological and electrophysiological benefits, and both had beneficial effects in terms of preventing dementia and relieving related health problems for elderly individuals.

scholarly journals ML-23 The outcome of malignant lymphoma of the central nervous system in a single institution

2020 ◽  
Vol 2 (Supplement_3) ◽  
pp. ii18-ii18
Author(s):  
Kiyonori Kuwahara ◽  
Shigeo Ohba ◽  
Kazuyasu Matsumura ◽  
Saeko Higashiguchi ◽  
Daijiro Kojima ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Adverse Events ◽  
Malignant Lymphoma ◽  
Survival Time ◽  
Progression Free Survival ◽  
Treatment Method ◽  
The Other ◽  
High Dose ◽  
Other Hand

Abstract Background: Although high dose-methotrexate therapy has been performed for primary central nervous system malignant lymphoma (PCNSL), R-MPV (rituximab, methotrexate (MTX), procarbazine and vincristine) therapy is currently the first line therapy for (PCNSL) in our hospital. This study examines the results of R-MPV therapy comparing with past treatment. Method/Subjects: Thirty-seven patients treated at our hospital from 2009 to 2020 were included. Overall survival time, progression free survival time, and toxicities were evaluated. Results: The average age of patients was 65.7 years. Patients included 21 males and 16 females. Thirty-six patients were diagnosed DLBCL by resected brain tumor tissues, and one was diagnosed DLBCL by vitreous biopsy. As initial treatment, rituximab±HD-MTX therapy (R±MTX group) was performed in 20 cases, HD-MTX therapy plus radiation (R±MTX+RT group) was performed in 12 cases, and RMPV therapy was performed in 5 cases (R-MPV group). Median OS of all cases was 69 months and median PFS was 38 months. Median OS was 69 months in R±MTX group and could not be calculated in R±MTX+RT, and R-MPV groups. Median PFS was 16 months and 56 months in R±MTX group and R±MTX+RT, respectively, and could not be calculated in the R-MPV group. Although the R-MPV group had a short follow-up period, the results were considered to be comparable to those of the R±MTX+RT group. On the other hand, grade 3/4 adverse events occurred in 50%, 25%, and 100%, respectively. Conclusion: R-MPV therapy may delay the timing of radiation and reduce the amount of radiation. On the other hand, the frequency of adverse events is high, and more strict management of treatment is required.

scholarly journals A supervised machine learning approach to characterize spinal network function

2019 ◽  
Vol 121 (6) ◽  
pp. 2001-2012 ◽  
Author(s):  
A. N. Dalrymple ◽  
S. A. Sharples ◽  
N. Osachoff ◽  
A. P. Lognon ◽  
P. J. Whelan
Keyword(s):  
Machine Learning ◽  
Spinal Cord ◽  
Nervous System ◽  
Spontaneous Activity ◽  
Machine Learning Algorithms ◽  
Supervised Machine Learning ◽  
Network Activity ◽  
Multilayer Perceptrons ◽  
Network Development ◽  
Newborn Mice

Spontaneous activity is a common feature of immature neuronal networks throughout the central nervous system and plays an important role in network development and consolidation. In postnatal rodents, spontaneous activity in the spinal cord exhibits complex, stochastic patterns that have historically proven challenging to characterize. We developed a software tool for quickly and automatically characterizing and classifying episodes of spontaneous activity generated from developing spinal networks. We recorded spontaneous activity from in vitro lumbar ventral roots of 16 neonatal [postnatal day (P)0–P3] mice. Recordings were DC coupled and detrended, and episodes were separated for analysis. Amplitude-, duration-, and frequency-related features were extracted from each episode and organized into five classes. Paired classes and features were used to train and test supervised machine learning algorithms. Multilayer perceptrons were used to classify episodes as rhythmic or multiburst. We increased network excitability with potassium chloride and tested the utility of the tool to detect changes in features and episode class. We also demonstrate usability by having a novel experimenter use the program to classify episodes collected at a later time point (P5). Supervised machine learning-based classification of episodes accounted for changes that traditional approaches cannot detect. Our tool, named SpontaneousClassification, advances the detail in which we can study not only developing spinal networks, but also spontaneous networks in other areas of the nervous system.NEW & NOTEWORTHY Spontaneous activity is important for nervous system network development and consolidation. Our software uses machine learning to automatically and quickly characterize and classify episodes of spontaneous activity in the spinal cord of newborn mice. It detected changes in network activity following KCl-enhanced excitation. Using our software to classify spontaneous activity throughout development, in pathological models, or with neuromodulation, may offer insight into the development and organization of spinal circuits.

Role of Autonomic Nervous System in Maintenance of Cerebral and Renal Hypertension

1957 ◽  
Vol 188 (2) ◽  
pp. 371-374 ◽  
Author(s):  
Sol Rothman ◽  
Douglas R. Drury
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Renal Hypertension ◽  
The Other ◽  
Peripheral Vasculature ◽  
Blood Pressures ◽  
Sympathetic Nervous ◽  
Blood Pressure Responses

The blood pressure responses to various drugs were investigated in renal hypertensive, cerebral hypertensive and normotensive rabbits. Hexamethonium bromide and Dibenamine reduced the blood pressures of renal and cerebral hypertensives. Effects in the normal were insignificant. The cerebral hypertensive's blood pressure was slightly affected by benzodioxane. Blood pressure was not reduced at all in the other groups. Blood pressure of the renal hypertensive rabbit was greatly reduced by Veriloid and dihydroergocornine. Blood pressures of cerebral and normal animals were affected to a lesser degree. The results suggest that maintenance of hypertension in the cerebral hypertensive rabbit depends on an overactive sympathetic nervous system, possibly due to the release of medullary pressor centers from inhibitory impulses originating in higher centers; whereas, the maintenance of hypertension in the renal hypertensive rabbit may be attributed to an increased reactivity of the peripheral vasculature to a normal sympathetic tone.

Fast Detoxification of Heroin Addicts by Acupuncture and Electrical Stimulation (AES) in Combination with Naloxone

1977 ◽  
Vol 05 (03n04) ◽  
pp. 257-263 ◽  
Author(s):  
H. L. WEN
Keyword(s):  
Nervous System ◽  
Electrical Stimulation ◽  
Parasympathetic Nervous System ◽  
The Other ◽  
Abstinence Syndrome ◽  
Rehabilitation Centre ◽  
Heroin Addicts ◽  
Social Rehabilitation ◽  
Receptor Sites ◽  
Long Acting

Detoxification can be accomplished more rapidly by first "flushing" the opiates from the receptor sites. Naloxone, a short antagonist displaces opiates from the receptor sites and such displacement precipitates an abstinence syndrome. Recently, a method of using acupuncture and electrical stimulation (AES) in combination with naloxone for fast detoxification was reported. This technique was applied to 50 cases of heroin addicts. Forty-one were detoxified. There were nine failures. Of the 41 cases, 18 patients were sent to rehabilitation centres and did not experience abstinence symptoms. Six were sent out of Hong Kong where heroin is not available, and two others did not go to a rehabilitation centre but still abstained. The other 15 were presumed to be on the drug. It is advocated that AES increases endorphin and relieves abstinence syndrome, but also at the same time inhibits the autonomic nervous system, mainly the parasympathetic nervous system. The technique does not stop the craving, therefore after detoxification, the patients should be sent for psycho-social rehabilitation, or alternatively be put on long acting antagonist.

On humoral factors in nervous activity

1935 ◽  
Vol 31 (6) ◽  
pp. 777-787
Author(s):  
D. S. Vorontsov
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nervous Activity ◽  
Active Part ◽  
Humoral Factors ◽  
The Central Nervous System ◽  
Relationship Of ◽  
The Relationship

Not only in the peripheral working organs, irritating substances are formed, which, as we can see, take an active part in their regulation, but also in the central nervous system, in the relationship of its individual elements, such substances apparently play an important role.

The influence of lithium on the competence of the ectoderm in Ambystoma mexicanum

Development ◽  
1964 ◽  
Vol 12 (2) ◽  
pp. 317-331
Author(s):  
D. O. E. Gebhardt ◽  
P. D. Nieuwkoop
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Ambystoma Mexicanum ◽  
The Other ◽  
Direct Influence ◽  
Amphibian Embryos ◽  
The Central Nervous System ◽  
The Subject ◽  
Morphogenetic Potential ◽  
Made In

The influence of lithium on the amphibian egg has been the subject of a number of investigations. From the work of Lehmann (1937), Töndury (1938), and Pasteels (1945) it is known that exposure of amphibian embryos to lithium results in a progressive cranio-caudal reduction of the central nervous system and a simultaneous conversion of the presumptive notochord into somites. Whereas these experiments were made with whole embryos, attempts have been made in recent years to localize the lithium effect by transplanting or explanting specific parts of the embryo. Gallera (1949), for instance, concluded from his experiments with transplants containing lithium treated presumptive chorda mesoderm, that lithium had reduced the ‘morphogenetic potential’ of this inductor. Lombard (1952), on the other hand, claimed that the susceptibility of amphibian eggs towards lithium was the result of the ion's direct influence on the ectoderm rather than on the presumptive archenteron roof.

Rapid Contractions and Associated Potentials in a Sand-Dwelling Anemone

1969 ◽  
Vol 51 (2) ◽  
pp. 513-528
Author(s):  
PETER E. PICKENS
Keyword(s):  
Maximum Size ◽  
Mechanical Stimulus ◽  
Retractor Muscle ◽  
Mechanical Stimuli ◽  
Nerve Impulses ◽  
Electrical Potentials ◽  
Spread Of Excitation ◽  
Electrical Stimuli ◽  
Withdrawal Response ◽  
Muscle Potential

1. Two kinds of electrical potentials can be recorded from the surface of the. retractor muscle of the anemone, Calamactis, during rapid contraction. These are large muscle action potentials and smaller pulses which are thought to be nerve spikes The latter resemble nerve impulses of higher organisms in that they are all-or-none and of short duration. 2. A nerve spike follows each of a pair of electrical stimuli, but the muscle potential and contraction occur only after the second shock, indicating that facilitation is required at the neuromuscular junction. 3. The size of the muscle potential and of the contraction are correlated with the interval between paired electrical stimuli. Maximum size is reached when stimuli are zoo msec. apart even though the minimum effective interval is 30 msec. 4. A muscle potential precedes contraction only along the upper part of the retractor muscle and this is the part that contracts rapidly during the withdrawal response. The lower retractor does not contract. 5. Conduction velocity along the upper retractor is higher than along the lower. The histological correlate of rapid conduction is a nerve net with large, long, longitudinally oriented fibres. 6. The refractory period of the conducting system of the upper retractor is shorter than that of the lower retractor. Consequently, spread of excitation toward the aboral end is limited if paired stimuli are further apart than 250-300 msec. 7. A mechanical stimulus which is just strong enough to elicit a withdrawal response evokes a single muscle potential of maximum size, suggesting that two nerve impulses closer together than 200 msec. precede the muscle potential. Stronger mechanical stimuli evoke a burst of muscle potentials.

The Co-Ordination of Insect Movements

1957 ◽  
Vol 34 (3) ◽  
pp. 306-333
Author(s):  
G. M. HUGHES
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
The Body ◽  
The Other ◽  
Limb Amputation ◽  
Normal Movement ◽  
Thoracic Ganglia ◽  
Blatta Orientalis ◽  
The Central Nervous System ◽  
Leg Movements

I. The effects of limb amputation and the cutting of commissures on the movements of the cockroach Blatta orientalis have been investigated with the aid of cinematography. Detailed analyses of changes in posture and rhythm of leg movements are given. 2. It is shown that quite marked changes occur following the amputation of a single leg or the cutting of a single commissure between the thoracic ganglia. 3. Changes following the amputation of a single leg are immediate and are such that the support normally provided by the missing leg is taken over by the two remaining legs on that side. Compensatory movements are also found in the contralateral legs. 4. When two legs of opposite sides are amputated it has been confirmed that the diagonal sequence tends to be adopted, but this is not invariably true. Besides alterations in the rhythm which this may involve, there are again adaptive modifications in the movements of the limbs with respect to the body. 5. When both comrnissures between the meso- and metathoracic ganglia are cut, the hind pair of legs fall out of rhythm with the other four legs. The observations on the effects of cutting commissures stress the importance of intersegmental pathways in co-ordination. 6. It is shown that all modifications following the amputation of legs may be related to the altered mechanical conditions. Some of the important factors involved in normal co-ordination are discussed, and it is suggested that the altered movements would be produced by the operation of these factors under the new conditions. It is concluded that the sensory inflow to the central nervous system is of major importance in the co-ordination of normal movement.

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