Differences in the effectiveness of reproduction among ten breeding strains of the common carpCyprinus carpioL. after stimulation of ovulation with carp pituitary homogenate or [(D-Ala6, Pro9NEt) mGnRH-a + metoclopramide] (Ovopel)

2016 ◽  
Vol 48 (5) ◽  
pp. 2221-2230 ◽  
Author(s):  
Beata Irena Cejko ◽  
Elżbieta Brzuska
Keyword(s):  
The Common ◽  
Stimulation Of ◽  
Pituitary Homogenate

scholarly journals The interaction between two trains of impulses converging on the same motoneurone

1929 ◽  
Vol 105 (738) ◽  
pp. 363-371 ◽  
Keyword(s):  
Mechanical Effect ◽  
The Other ◽  
Muscle Fibres ◽  
Flexor Muscle ◽  
Afferent Pathways ◽  
Afferent Nerves ◽  
Maximal Stimulation ◽  
The Common ◽  
The Relationship ◽  
Stimulation Of

It was shown in an earlier paper (7) that if maximal stimulation of either of two different afferent nerves can reflexly excite fractions of a given flexor muscle, there are generally, within the aggregate of neurones which innervate that muscle, motoneurones which can be caused to discharge by either afferent (i. e., motoneurones common to both fractions). The relationship which two such afferents bear to a common motoneurone was shown, by the isometric method of recording contraction, to be such that the activation of one afferent, at a speed sufficient to cause a maximal motor tetanus when trans­mitted to the muscle fibres, caused exclusion of any added mechanical effect when the other afferent was excited concurrently. This default in mechanical effect was called “occlusion.” Occlusion may conceivably be due to total exclusion of the effect of one afferent pathway on the common motoneurone by the activity of the other; but facilitation of the effect of one path by the activation of the other when the stimuli were minimal suggests that, in some circumstances at least, the effect of each could augment and summate with th at of the other at the place of convergence of two afferent pathways. Further investigation, using the action currents of the muscle as indication of the nerve impulses discharged by the motoneurone units, has now given some information regarding the effect of impulses arriving at the locus of convergence by one afferent path when the unit common to both is already discharging in response to impulses arriving by the other afferent path. Our method has been to excite both afferent nerves in overlapping sequence by series of break shocks at a rapid rate and to examine the action currents of the resulting reflex for evidence of the appearance of the rhythm of the second series in the discharge caused by the first when the two series are both reaching the motoneurone.

Connections between thoraco-coxal proprioceptive afferents and motor neurons in the locust

2000 ◽  
Vol 203 (3) ◽  
pp. 435-445
Author(s):  
M. Wildman
Keyword(s):  
Electrical Stimulation ◽  
Sensory Neurons ◽  
Motor Neurons ◽  
Chordotonal Organ ◽  
Synaptic Connections ◽  
Afferent Neurons ◽  
Postsynaptic Potentials ◽  
The Common ◽  
Proprioceptive Afferents ◽  
Stimulation Of

The position of the coxal segment of the locust hind leg relative to the thorax is monitored by a variety of proprioceptors, including three chordotonal organs and a myochordotonal organ. The sensory neurons of two of these proprioceptors, the posterior joint chordotonal organ (pjCO) and the myochordotonal organ (MCO), have axons in the purely sensory metathoracic nerve 2C (N2C). The connections made by these afferents with metathoracic motor neurons innervating thoraco-coxal and wing muscles were investigated by electrical stimulation of N2C and by matching postsynaptic potentials in motor neurons with afferent spikes in N2C. Stretch applied to the anterior rotator muscle of the coxa (M121), with which the MCO is associated, evoked sensory spikes in N2C. Some of the MCO afferent neurons make direct excitatory chemical synaptic connections with motor neurons innervating the thoraco-coxal muscles M121, M126 and M125. Parallel polysynaptic pathways via unidentified interneurons also exist between MCO afferents and these motor neurons. Connections with the common inhibitor 1 neuron and motor neurons innervating the thoraco-coxal muscles M123/4 and wing muscles M113 and M127 are polysynaptic. Afferents of the pjCO also make polysynaptic connections with motor neurons innervating thoraco-coxal and wing muscles, but no evidence for monosynaptic pathways was found.

Extra Force From Asynchronous Stimulation of Cat Soleus Muscle Results From Minimizing the Stretch of the Common Elastic Elements

2006 ◽  
Vol 96 (3) ◽  
pp. 1401-1405 ◽  
Author(s):  
Thomas G. Sandercock
Keyword(s):  
Low Frequency ◽  
Muscle Length ◽  
Test Frequency ◽  
The Common ◽  
Tension Curve ◽  
Ventral Roots ◽  
The Difference ◽  
Dynamic Stretch ◽  
Elastic Elements ◽  
Stimulation Of

Rack and Westbury showed that low-frequency asynchronous stimulation of a muscle produces greater force compared with synchronous stimulation. This study tested the hypothesis that the difference results from the dynamic stretch of the common elastic elements. In eight anesthetized cats, the soleus was attached to a servomechanism to control muscle length and record force. The ventral roots were divided into four bundles so each innervated approximately 1/4 of the soleus. The elasticity shared by each part of the muscle was estimated and the servomechanism programmed to compensate for its stretch. At each test frequency (5, 7.5, and 10 Hz), the muscle was stimulated by asynchronous stimulation, synchronous stimulation, summation of force with each part stimulated individually, and summation with each part stimulated individually and the servomechanism mimicking tendon stretch during asynchronous stimulation. Muscle length was isometric except for the last protocol. The observed differences were small. The greatest difference occurred during stimulation at 5 Hz with muscle length on the ascending limb of the length-tension curve. Here, the average forces, normalized by asynchronous force, were asynchronous, 100%; synchronous, 73%; summation, 110%; and summation with stretch compensation, 98%. The results support the hypothesis and suggest that the common elasticity can be used to predict force gains from asynchronous stimulation.

CLINICAL INVESTIGATION IN PEDIATRIC PRACTICE

PEDIATRICS ◽  
1956 ◽  
Vol 18 (1) ◽  
pp. 90-94
Author(s):  
John C. Wilcox
Keyword(s):  
Clinical Study ◽  
Teaching Hospital ◽  
Clinical Investigation ◽  
Medical Knowledge ◽  
Academic Standards ◽  
Pediatric Practice ◽  
The World ◽  
Common Purpose ◽  
The Common ◽  
Stimulation Of

WHILE recognizing that the common purpose of all clinical investigation is the benefit of the patient through the advancement of medical knowledge, there are other justifications and sources of inspiration which may be more immediately gained objectives. This is true whether the investigator is a professor of pediatrics or his country cousin. It is the purpose of this paper to compare the natures of those immediate objectives as they apply to clinical investigation carried on in a teaching center with clinical investigation performed in pediatric practice. In making this comparison, I do not intend to imply that the professor of pediatrics or a member of his staff has at his beck and call large crews of laboratory technicians, roomtuis of pretty secretaries and efficient stenographers, tabulators and computers in frightening array, scads of money neatly tagged for research and all the time in the world—and that none of these is possessed by the practitioner. Instead, I will point out that in spite of a seemingly vast gulf of separation in facilities and resources, there are similarities of purpose which serve to give reflected dignity to any reasonable and seriously pursued clinical study even though it be attempted under primitive conditions by academic standards. The professor, gazing from the porticoed façade of a teaching hospital and contemplating his next venture into publication [SEE FIG. 1., FIG. 2. IN SOURCE PDF] (Fig. 1), looks in 1 of 3 possible directions for stimulation. Each of these corresponds with 1 of 3 responsibilities: (1) instruction of students; (2) scientific stimulation of pediatric confreres; (3) the recognition of academic superiors.

scholarly journals Hormesis in Plants: The Role of Oxidative Stress, Auxins and Photosynthesis in Corn Treated with Cd or Pb

2020 ◽  
Vol 21 (6) ◽  
pp. 2099 ◽  
Author(s):  
Eugeniusz Małkowski ◽  
Krzysztof Sitko ◽  
Michał Szopiński ◽  
Żaneta Gieroń ◽  
Marta Pogrzeba ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Shoot Growth ◽  
Photosynthetic Apparatus ◽  
Growth Stimulation ◽  
Photosynthetic Parameters ◽  
Toxic Substances ◽  
Wide Range ◽  
The Common ◽  
Stimulation Of

Hormesis, which describes the stimulatory effect of low doses of toxic substances on growth, is a well-known phenomenon in the plant and animal kingdoms. However, the mechanisms that are involved in this phenomenon are still poorly understood. We performed preliminary studies on corn coleoptile sections, which showed a positive correlation between the stimulation of growth by Cd or Pb and an increase in the auxin and H2O2 content in the coleoptile sections. Subsequently, we grew corn seedlings in hydroponic culture and tested a wide range of Cd or Pb concentrations in order to determine hormetic growth stimulation. In these seedlings the gas exchange and the chlorophyll a fluorescence, as well as the content of chlorophyll, flavonol, auxin and hydrogen peroxide, were measured. We found that during the hormetic stimulation of growth, the response of the photosynthetic apparatus to Cd and Pb differed significantly. While the application of Cd mostly caused a decrease in various photosynthetic parameters, the application of Pb stimulated some of them. Nevertheless, we discovered that the common features of the hormetic stimulation of shoot growth by heavy metals are an increase in the auxin and flavonol content and the maintenance of hydrogen peroxide at the same level as the control plants.

scholarly journals Arm movements induced by noninvasive optogenetic stimulation of the motor cortex in the common marmoset

2019 ◽  
Vol 116 (45) ◽  
pp. 22844-22850 ◽  
Author(s):  
Teppei Ebina ◽  
Keitaro Obara ◽  
Akiya Watakabe ◽  
Yoshito Masamizu ◽  
Shin-Ichiro Terada ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Nonhuman Primates ◽  
Arm Movements ◽  
Common Marmoset ◽  
Blue Laser ◽  
Optogenetic Stimulation ◽  
Long Duration ◽  
The Common ◽  
Forelimb Movements ◽  
Stimulation Of

Optogenetics is now a fundamental tool for investigating the relationship between neuronal activity and behavior. However, its application to the investigation of motor control systems in nonhuman primates is rather limited, because optogenetic stimulation of cortical neurons in nonhuman primates has failed to induce or modulate any hand/arm movements. Here, we used a tetracycline-inducible gene expression system carrying CaMKII promoter and the gene encoding a Channelrhodopsin-2 variant with fast kinetics in the common marmoset, a small New World monkey. In an awake state, forelimb movements could be induced when Channelrhodopsin-2−expressing neurons in the motor cortex were illuminated by blue laser light with a spot diameter of 1 mm or 2 mm through a cranial window without cortical invasion. Forelimb muscles responded 10 ms to 50 ms after photostimulation onset. Long-duration (500 ms) photostimulation induced discrete forelimb movements that could be markerlessly tracked with charge-coupled device cameras and a deep learning algorithm. Long-duration photostimulation mapping revealed that the primary motor cortex is divided into multiple domains that can induce hand and elbow movements in different directions. During performance of a forelimb movement task, movement trajectories were modulated by weak photostimulation, which did not induce visible forelimb movements at rest, around the onset of task-relevant movement. The modulation was biased toward the movement direction induced by the strong photostimulation. Combined with calcium imaging, all-optical interrogation of motor circuits should be possible in behaving marmosets.

scholarly journals The application of [D-Tle6,ProNHEt9]mGnRH (Lecirelin) with the dopaminergic inhibitor metoclopramide to stimulate ovulation in African catfish (Clarias gariepinus)

2011 ◽  
Vol 49 (No. 7) ◽  
pp. 297-306 ◽  
Author(s):  
E. Brzuska ◽  
J. Kouřil ◽  
J. Adamek ◽  
Z. Stupka ◽  
V. Bekh
Keyword(s):  
Body Weight ◽  
Female Body ◽  
Clarias Gariepinus ◽  
The Body ◽  
African Catfish ◽  
Average Body ◽  
Stimulation Of ◽  
Average Body Weight ◽  
Pituitary Homogenate

The results of reproduction were tested in females of the African catfish (Clarias gariepinus Burchell 1822) after stimulation of ovulation with carp pituitary (4 mg/kg body weight) or with Lecirelin (15 μg/kg) and metoclopramide (10 mg/kg). After administering the synthetic substance eggs were obtained from all females while in the group treated with pituitary homogenate 7 out of 8 hypophysed females spawned. The applied spawning agent did not significantly influence the weight of eggs expressed in grams, but in the case of females treated with carp pituitary homogenate a significantly higher weight of eggs expressed as the percentage of body weight of fish was recorded. The applied stimulators of ovulation did not affect any trait reflecting the quality of eggs. Females used as an experimental material belonged to two categories in respect of body weight: lighter females with average body weight of 2.63 ± 0.36 kg and heavier females with average body weight of 3.91 ± 0.48 kg. It was proved that the weight of eggs expressed either in grams or as a percentage of a female’s weight was significantly related to the body weight of a female (P ≤ 0.01 and P ≤ 0.05, respectively), as well as the percentage of fertilised eggs and the percentage of living embryos after 28 hours of incubation (P ≤ 0.05 and P ≤ 0.05, respectively). The interaction between the stimulator of ovulation and the female body weight was significant only for traits reflecting the weight of obtained eggs (P ≤ 0.05 and P ≤ 0.01).  

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