scholarly journals Command Interneurons in the Crayfish Central Nervous System

1967 ◽  
Vol 46 (2) ◽  
pp. 249-261
Author(s):  
H. L. ATWOOD ◽  
C. A. G. WIERSMA
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Temporal Pattern ◽  
Motor Output ◽  
Evoked Response ◽  
Total Response ◽  
Motor Effects ◽  
Frequency Of Stimulation ◽  
Stimulation Of

1. The motor effects evoked by stimulation of each of eight command fibres in the circumoesophageal commissures of the crayfish are described. 2. The fibres obtained appeared to have widespread connexions in all or most of the lower ganglia. For certain fibres the response was stronger on the homolateral side of the animal; for others it was symmetrical. 3. The frequency of stimulation of a command fibre generally had a pronounced influence on the speed of the evoked response. In addition, segments of the total response could be elicited selectively by alteration of the frequency and duration of stimulation. 4. Although the responses associated with most of the fibres were not sensitive to the fine temporal pattern of the applied stimulation, for one fibre the motor output depended clearly on the spacing of the stimulating pulses.

Central Nervous System and Pituitary Mechanisms in Dopaminergic Stimulation of Growth Hormone Release in Women

1981 ◽  
Vol 32 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Carlo Ferrari ◽  
Roberto Caldara ◽  
Cristiano Barbieri ◽  
Paolo Testori ◽  
Rosanna Benco ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Growth Hormone ◽  
Nervous System ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Dopaminergic Stimulation ◽  
Stimulation Of

scholarly journals VI. —Anaphylaxis and anaphylatoxins

1923 ◽  
Vol 211 (382-390) ◽  
pp. 273-315 ◽  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Guinea Pig ◽  
Anaphylactic Shock ◽  
The Body ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Fundamental Conception ◽  
The Central Nervous System ◽  
Stimulation Of

In the study of the phenomena of anaphylaxis there are certain points on which some measure of agreement seems to have been attained. In the case of anaphylaxis to soluble proteins, with which alone we are directly concerned in this paper, the majority of investigators probably accept the view that the condition is due to the formation of an antibody of the precipitin type. Concerning the method, however, by which the presence of this antibody causes the specific sensitiveness, the means by which its interaction with the antibody produces the anaphylactic shock, there is a wide divergence of conception. Two main currents of speculation can be discerned. One view, historically rather the earlier, and first put forward by Besredka (1) attributes the anaphylactic condition to the location of the antibody in the body cells. There is not complete unanimity among adherents of this view as to the nature of the antibody concerned, or as to the class of cells containing it which are primarily affected in the anaphylactic shock. Besredka (2) himself has apparently not accepted the identification of the anaphylactic antibody with a precipitin, but regards it as belonging to a special class (sensibilisine). He also regards the cells of the central nervous system as those primarily involved in the anaphylactic shock in the guinea-pig. Others, including one of us (3), have found no adequate reason for rejecting the strong evidence in favour of the precipitin nature of the anaphylactic antibody, produced by Doerr and Russ (4), Weil (5), and others, and have accepted and confirmed the description of the rapid anaphylactic death in the guinea-pig as due to a direct stimulation of the plain-muscle fibres surrounding the bronchioles, causing valve-like obstruction of the lumen, and leading to asphyxia, with the characteristic fixed distension of the lungs, as first described by Auer and Lewis (6), and almost simultaneously by Biedl and Kraus (7). But the fundamental conception of anaphylaxis as due to cellular location of an antibody, and of the reaction as due to the union of antigen and antibody taking place in the protoplasm, is common to a number of workers who thus differ on details.

Blood Pressure and Pulse Rate in the Foetal Sheep

1945 ◽  
Vol 22 (1-2) ◽  
pp. 63-74
Author(s):  
JOSEPH BARCROFT ◽  
D. H. BARRON
Keyword(s):  
Blood Pressure ◽  
Central Nervous System ◽  
Nervous System ◽  
Pulse Rate ◽  
Umbilical Artery ◽  
The Central Nervous System ◽  
The Right ◽  
First Moment ◽  
Left Vagus ◽  
Stimulation Of

1. A method (the needle method) is described for the measurement of the pressure in the stream going through a vessel. 2. In the foetal sheep the needle method applied to the umbilical artery gives substantially the same results as the mercurial manometer applied to the carotid, until about half-way through the gestation period. 3. As gestation proceeds the needle method applied at the first moment at which it can be applied to the umbilical artery (or a branch) gives readings substantially lower, and increasingly lower as gestation proceeds, than does the mercurial manometer read at the first moment at which it can be read. 4. The discrepancy is due to the sum of a number of causes which are discussed, but of these the most important is an actual rise of pressure between the time of delivery and the completion of the dissections contingent on the use of the mercurial manometer. 5. The cause of this is not at present demonstrated, but either or both of two factors may be concerned: (a) a dulling of the central nervous system which weakens the depressor reflex; (b) the establishment of a greater degree of vasomotor tone consequent on the bombardment of the central nervous system with sensory stimuli. 6. The pulse rates in utero and just after delivery of the foetus into a saline bath at 39-40°C. (the umbilical circulation being unimpaired) are not significantly different. 7. The pulse rate quickens up to the 70th-80th day, after which it becomes slower as gestation proceeds. 8. If both vagi be severed, the pulse rate te to quicken throughout gestation. The pulse, therefore, comes increasingly under vagus inhibition from the 80th-90th day onwards. 9. Even after the vagi have been cut after the 120th day (it has not been tried before) adrenalin in sufficient quantity will cause a further quickening of the pulse. 10. The earliest date at which stimulation of the peripheral end of the right vagus was observed to slow the heart was the 77th day. On the 85th day peripheral stimulation of the left vagus also failed, but succeeded on the 101st day. 11. Central stimulation of the left vagus, with the right vagus intact, produced slowing on the 77th day. 12. Slowing of the heart synchronous with rise of arterial pressure has been observed on the 111th day. 13. Slowing of the heart which bears evidence of being reflex has been obtained by raising the blood pressure (clamping the cord) on the 121st day and by injection of adrenalin on the 118th day. 14. Approaching term both the carotid sinus and cardiac depressor mechanisms are functional. 15. Lowering of the blood pressure as the result of stimulation of the central end of the vagus and with both vagi severed can be demonstrated late in gestation.

Pulmonary Reflexes in Pulmonary Edema?

1957 ◽  
Vol 189 (1) ◽  
pp. 132-136 ◽  
Author(s):  
C. Aravanis ◽  
A. Libretti ◽  
E. Jona ◽  
J. F. Polli ◽  
C. K. Liu ◽  
...  
Keyword(s):  
Central Nervous System ◽  
High Pressure ◽  
Nervous System ◽  
Pulmonary Artery ◽  
Pulmonary Edema ◽  
Pulmonary Veins ◽  
Systemic Circulation ◽  
Left Ventricular ◽  
Additional Element ◽  
Stimulation Of

The mechanism of pulmonary edema caused by stimulation of the central nervous system was studied in 33 dogs. Stimulation was obtained by the intracisternal injection of veratrine, or of air or saline under high pressure, or by electric stimulation of the hypothalamus. Pressure changes in the pulmonary artery, left atrium and left ventricle were recorded by means of three catheters introduced through the right external jugular vein and the left femoral artery. Experiments were performed with closed or open chest, and following ligation of the thoracic aorta and inferior cava. Lung opacity was studied as a means to estimate the blood content of this organ. Data obtained in closed-chest experiments suggest that a blood shift from the systemic to the pulmonary circulation may be a factor in veratrine-induced pulmonary edema. This was confirmed by the observation that, following mechanical exclusion of the systemic circulation, no pulmonary edema occurred while the changes of left ventricular pressure were minimal and inconstant. In these animals, pulmonary artery pressure still rose indicating vasoconstriction while an increase of lung opacity suggested that the vasoconstriction was greater in the pulmonary veins than in the arteries. Injection of air or saline under high pressure into the cisterna magna and faradic stimulation of the hypothalamus caused pulmonary hypertension, even after exclusion of the systemic circulation. In these experiments, a decreased lung opacity suggested that the pulmonary constriction was greater on the arterial than on the venous side. These findings are offered as evidence that the caliber of the pulmonary vessels may be influenced by central nervous system stimulation, an additional element to be considered in the mechanism of pulmonary edema.

Central nervous system effect of calcitonin: Stimulation of prolactin release in rats

1982 ◽  
Vol 248 (2) ◽  
pp. 331-339 ◽  
Author(s):  
Kazuo Chihara ◽  
Junji Iwasaki ◽  
Yoshiko Iwasaki ◽  
Naoto Minamitani ◽  
Hidesuke Kaji ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Central Nervous System Effect ◽  
Prolactin Release ◽  
System Effect ◽  
Stimulation Of

Experiments on the central pattern generator for swimming in amphibian embryos

1982 ◽  
Vol 296 (1081) ◽  
pp. 229-243 ◽  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Pattern Generator ◽  
Pattern Generation ◽  
Motor Output ◽  
Cycle Period ◽  
Sensory Stimuli ◽  
Swimming Pattern ◽  
Left And Right

The central nervous system of paralysed Xenopus laevis embryos can generate a motor output pattern suitable for swimming locomotion. By recording motor root activity in paralysed embryos with transected nervous systems we have shown that: (a) the spinal cord is capable of swimming pattern generation; (b) swimming pattern generator capability in the hindbrain and spinal cord is distributed; (c) caudal hindbrain is necessary for sustained swimming output after discrete stimulation. By recording similarly from embryos whose central nervous system was divided longitudinally into left and right sides, we have shown that: (a) each side can generate rhythmic motor output with cycle periods like those in swimming; (b) during this activity cycle period increases within an episode, and there is the usual rostrocaudal delay found in swimming; (c) this activity is influenced by sensory stimuli in the same way as swimming activity; ( d) normal phase coupling of the left and right sides can be established by the ventral commissure in the spinal cord. We conclude that interactions between the antagonistic (left and right) motor systems are not necessary for swimming rhythm generation and present a model for swimming pattern generation where autonomous rhythm generators on each side of the nervous system drive the motoneurons. Alternation is achieved by reciprocal inhibition, and activity is initiated and maintained by tonic excitation from the hindbrain.

Optical Stimulation of the Central Nervous System In Vitro

2008 ◽  
Author(s):  
Jonathan M. Cayce ◽  
Chris Kao ◽  
Jonathan D. Malphurus ◽  
Peter Konrad ◽  
Duco Jansen ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Optical Stimulation ◽  
The Central Nervous System ◽  
Stimulation Of
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