Thoracic Leg Control of Abdominal Extension in the Crayfish, Procambarus Clarkii

1981 ◽  
Vol 90 (1) ◽  
pp. 85-100
Author(s):  
CHARLES H. PAGE
Keyword(s):  
Procambarus Clarkii ◽  
Mean Values ◽  
Extensor Muscles ◽  
Carpal Joint ◽  
The Mean ◽  
Leg Movement ◽  
Abdominal Appendages ◽  
Thoracic And Abdominal ◽  
Abdominal Movement ◽  
Stimulation Of

Postural extensions of the abdomen of the crayfish, Procambarus clarkii, could be evoked by mechanical stimulation of a single thoracic leg. Movement of a single leg joint was sufficient to initiate an extension response. Vigorous abdominal extensions were initiated either by depression of the whole leg (WLD) or by flexion of the mero-carpal joint (MCF). Weaker extension responses were obtained by depression of the thoracic-coxal and coxo-basal joints. Similar stimulation of the chelipeds did not elicit an abdominal extension response. Single-frame analysis of motion pictures of crayfish responding to WLD or MCF stimulation of a 2nd thoracic leg showed that the responses evoked by the two different stimulus situations were nearly identical. They differed principally in the responses of the leg located contralateral to the stimulated leg. Movements of most of the cephalic, thoracic and abdominal appendages accompanied the abdominal extension response. Only the eyes remained stationary throughout the response. The mean values of the latencies for the initiation of appendage movement ranged from 125 to 204 ma; abdominal movement had a mean latency of about 220 ms. The abdominal extension reflex resulted from the activity of the tonic superficial extensor muscles. The deep phasic extensor muscles were silent during the response. The mean latencies for the initiation of superficial extensor muscle activity by WLD and MCF stimulation were 53·7 and 50·0 ms respectively.

Monosynaptic EPSPs in primate lumbar motoneurons

1993 ◽  
Vol 70 (4) ◽  
pp. 1585-1592 ◽  
Author(s):  
J. S. Carp
Keyword(s):  
Input Resistance ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Macaca Nemestrina ◽  
Synaptic Connectivity ◽  
Lateral Gastrocnemius ◽  
Mean Values ◽  
Epsp Amplitude ◽  
The Mean ◽  
Stimulation Of

1. Homonymous and heteronymous monosynaptic composite excitatory postsynaptic potentials (EPSPs) were evaluated by intracellular recordings from 89 motoneurons innervating triceps surae (n = 59) and more distal (n = 30) muscles in 14 pentobarbital-anesthetized monkeys (Macaca nemestrina). 2. Homonymous EPSPs were found in all motoneurons tested. The mean values +/- SD for maximum EPSP amplitude of triceps surae motoneurons were 2.5 +/- 1.3, 1.8 +/- 1.3 and 4.5 +/- 2.0 mV for medial gastrocnemius, lateral gastrocnemius, and soleus motoneurons, respectively. Heteronymous EPSPs were almost always smaller than their corresponding homonymous EPSPs. 3. Triceps surae EPSP amplitude was larger in motoneurons with higher input resistance. However, this relationship was weak, suggesting that factors related to input resistance play a limited role in determining the magnitude of the EPSP. 4. The mean ratio +/- SD of the amplitude of the EPSP elicited by combined stimulation of all triceps surae nerves to the amplitude of the algebraic sum of the three individual EPSPs was 0.95 +/- 0.05. This ratio was greater in motoneurons with lower rheobase. 5. Some patterns of synaptic connectivity in the macaque are consistent with previously reported differences between primates and cat (e.g., heteronymous EPSPs elicited by medial gastrocnemius nerve stimulation in soleus motoneurons are small in macaque and other primates but large in cat). However, no overall pattern emerges from a comparison of the similarities and differences in EPSPs among species in which they have been studied (i.e., macaque, baboon, and cat). That is, there are no two species in which EPSP properties are consistently similar to each other, but different from those of the third species.(ABSTRACT TRUNCATED AT 250 WORDS)

Sets of synaptic currents paired by common presynaptic or postsynaptic neurons

1989 ◽  
Vol 61 (4) ◽  
pp. 845-853 ◽  
Author(s):  
D. Gardner
Keyword(s):  
Synaptic Currents ◽  
Mean Values ◽  
First Case ◽  
Postsynaptic Cell ◽  
Intracellular Stimulation ◽  
The Common ◽  
The Mean ◽  
Cell Networks ◽  
Stimulation Of ◽  
Presynaptic Neurons

1. In the buccal ganglia of Aplysia, presynaptic neurons B4 and B5 produce similar inhibitory postsynaptic currents (PSCs) in several postsynaptic follower cells. Previous work has shown that both duration and amplitude of these PSCs vary, that each parameter may be altered transiently by manipulating presynaptic activity, and that these variations affect synaptic efficacy. 2. To permit synapse-to-synapse comparisons, the mean and coefficient of variation (CV) of both peak conductance (gpeak) and time constant of decay (tau) were determined for sets of synaptic currents evoked by direct intracellular stimulation of presynaptic neurons. For 56 synapses, gpeak = 0.40 +/- 0.33 (SD) microS for a CV of 0.83, and tau = 19.7 +/- 4.0 ms for a CV of 0.20. The synapse-to-synapse variability was within 5% of values obtained from a previous population. 3. The relative contributions of presynaptic and postsynaptic factors to efficacy and variability of PSCs were examined by recordings from two classes of three-cell networks and by comparing values of gpeak and tau at synapses sharing a common presynaptic or postsynaptic neuron. 4. In the first case, paired presynaptic inputs from B4 and B5 converged on a common postsynaptic cell. For 16 examples of this case, mean values of both gpeak and tau recorded in a single follower cell, but produced by different presynaptic neurons, were significantly closer than those recorded in different followers (P less than 0.001). The common postsynaptic cell did not constrain variability of these parameters; CVs for paired synapses were not significantly different from the population (P greater than 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

The Swimmeret Rhythm and its Relationships with Postural and Locomotor Activity in the Isolated Nervous System of the Crayfish Procambarus Clarkii

1991 ◽  
Vol 157 (1) ◽  
pp. 205-226
Author(s):  
JEAN-YVES BARTHE ◽  
MICHELLE BÉVENGUT ◽  
FRANÇOIS CLARAC
Keyword(s):  
Nerve Cord ◽  
Procambarus Clarkii ◽  
Rhythmic Activity ◽  
Metachronal Wave ◽  
Rhythmic Motor ◽  
Motor Outputs ◽  
Thoracic And Abdominal ◽  
Peripheral Sensory ◽  
Stimulation Of

An in vitro preparation was developed consisting of the five thoracic and abdominal ganglia of the crayfish nerve cord, isolated from anterior nervous structures and from peripheral sensory inputs. The central activities of the thoracic leg, swimmeret and abdominal positioning motor systems and their relationships were studied. When motor outputs were tonic in the thoracic leg nerves (90% of the preparations), continuous rhythmic activity occurred and persisted for several hours in the swimmeret nerves. Interruptions of the swimmeret rhythm were associated with rhythmic motor outputs in the leg nerves (10% of the preparations). Motor activity in the abdominal positioning system was mainly tonic. Swimmeret rhythm reversibly disappeared during application of a sucrose block between the thoracic and abdominal parts of the nerve cord. Electrical stimulation of the connectives posterior to the block induced bouts of rhythmic swimmeret activity. Comparisons of the swimmeret rhythm (period) and the metachronal wave (duration, phase) showed that sectioning of the connectives between the thoracic and abdominal ganglia modified the period but did not affect the properties of the metachronal wave. We conclude that the presence of descending inputs from thoracic ganglia is necessary for persistent swimmeret activity.

A transcellular route for Na-coupled Cl transport in secreting pancreatic acinar cells

1983 ◽  
Vol 245 (4) ◽  
pp. G499-G503 ◽  
Author(s):  
J. O'Doherty ◽  
R. J. Stark
Keyword(s):  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Coupling Mechanism ◽  
Enzyme Release ◽  
Electrochemical Gradient ◽  
Mean Values ◽  
Electrode Potentials ◽  
The Mean ◽  
Induced Changes ◽  
Stimulation Of

Ion-selective microelectrodes were employed to determine the electrochemical driving forces involved in the transepithelial transport of Na+ and Cl- during acetylcholine (ACh) stimulation of pancreatic acinar cells. In HCO-3-free Ringer solution, the mean values of intracellular Cl and Na activities (aiCl and aiNa) were 68.9 +/- 1.1 and 8.3 +/- 0.3 mM, respectively. The mean value of aiCl is above the calculated equilibrium value, indicating that Cl entry into the cell is an energy-requiring process. Continuous measurement of intracellular electrode potentials during stimulation of the cells with concentrations of ACh ranging from 10(-7) to 10(-5) M demonstrated the neurotransmitter's influence on transmembrane Na+ and Cl- movement in secreting cells. The mean values of the induced changes in aiCl and aiNa at every concentration of ACh measured were not significantly different (P greater than 0.5), although the mean changes in either aiNa or aiCl determined with every decade change in ACh concentration were significant (P less than 0.05). The transmembrane Na+ electrochemical gradient dissipated with the induced increases in aiCl. These results suggest that, during stimulus-secretion coupling of pancreatic acinar cells, there is a transcellular route for NaCl secretion, and the energy for NaCl entry into the cell may be derived from the Na+ electrochemical gradient that exists across the basolateral epithelial membrane. They also suggest that the ACh-induced changes in ionic permeability of the plasma membrane may be the coupling mechanism by which the simultaneous events enzyme release and electrolyte secretion are controlled in stimulated cells.

Articulatory Behavior Pre and Post Full-Mouth Tooth Extraction and Alveoloplasty

1980 ◽  
Vol 23 (3) ◽  
pp. 630-645 ◽  
Author(s):  
Gerald Zimmermann ◽  
J.A. Scott Kelso ◽  
Larry Lander
Keyword(s):  
Control Subject ◽  
High Speed ◽  
Tooth Extraction ◽  
Kinematic Parameters ◽  
Experimental Conditions ◽  
Mean Values ◽  
Articulatory Movements ◽  
The Mean ◽  
Experimental Subjects ◽  
Normal Speech

High speed cinefluorography was used to track articulatory movements preceding and following full-mouth tooth extraction and alveoloplasty in two subjects. Films also were made of a control subject on two separate days. The purpose of the study was to determine the effects of dramatically altering the structural dimensions of the oral cavity on the kinematic parameters of speech. The results showed that the experimental subjects performed differently pre and postoperatively though the changes were in different directions for the two subjects. Differences in both means and variabilities of kinematic parameters were larger between days for the experimental (operated) subjects than for the control subject. The results for the Control subject also showed significant differences in the mean values of kinematic variables between days though these day-to-day differences could not account for the effects found pre- and postoperatively. The results of the kinematic analysis, particularly the finding that transition time was most stable over the experimental conditions for the operated subjects, are used to speculate about the coordination of normal speech.

Comparative Study of Intranasal, Subcutaneous and Intravenous Administration of Desamino-D-Arginine Vasopressin (DDAVP)

1986 ◽  
Vol 55 (01) ◽  
pp. 108-111 ◽  
Author(s):  
M Köhler ◽  
P Hellstern ◽  
C Miyashita ◽  
G von Blohn ◽  
E Wenzel
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Factor Xii ◽  
Additional Advantage ◽  
Mean Values ◽  
Routes Of Administration ◽  
The Mean ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Factor Antigen

SummaryThis study was performed to evaluate the influence of different routes of administration on the efficacy of DDAVP treatment. Ten healthy volunteers received DDAVP intranasally (i.n.), subcutaneously (s.c.) and intravenously (i.v.) in a randomized cross-over trial. Factor XII and high molecular weight (HMW)-kininogen levels increased only slightly after DDAVP administration. The mean increase of factor VIII: C was 3.1 (i. v.), 2.3 (s. c.), and 1.3 (i.n.) - fold over baseline. Ristocetin cofactor (von Willebrand factor antigen) increased 3.1 (2.5), 2.0 (2.3) and 1.2 (1.2) - fold over baseline mean values after i.v., s.c. and i.n. DDAVP, respectively. The half-disappearance time of factor VIII and von Willebrand factor (vWF) after DDAVP ranged from five (factor VIII: C) to eight hours (vWF). The mean increase of fibrinolytic activity was more pronounced after i.v. DDAVP. The antidiuretic effect was moderate with no apparent differences between the routes of application. This study provides further evidence that both i.v. and s.c. DDAVP administration result in an appropriate and reliable stimulation of haemostasis. An additional advantage of s. c. administration is its suitability for home treatment.

Comparative Study of effectiveness of mobilization with movement (MWM) and End range mobilization (ERM) techniques in frozen shoulder

2018 ◽  
Vol 4 (4) ◽  
pp. 519-522
Author(s):  
Jeyakumar S ◽  
Jagatheesan Alagesan ◽  
T.S. Muthukumar
Keyword(s):  
Range Of Motion ◽  
Frozen Shoulder ◽  
Type I ◽  
Mean Values ◽  
Functional Activities ◽  
Group A ◽  
The Mean ◽  
Group B

Background: Frozen shoulder is disorder of the connective tissue that limits the normal Range of motion of the shoulder in diabetes, frozen shoulder is thought to be caused by changes to the collagen in the shoulder joint as a result of long term Hypoglycemia. Mobilization is a therapeutic movement of the joint. The goal is to restore normal joint motion and rhythm. The use of mobilization with movement for peripheral joints was developed by mulligan. This technique combines a sustained application of manual technique “gliding” force to the joint with concurrent physiologic motion of joint, either actively or passively. This study aims to find out the effects of mobilization with movement and end range mobilization in frozen shoulder in Type I diabetics. Materials and Methods: 30 subjects both male and female, suffering with shoulder pain and clinically diagnosed with frozen shoulder was recruited for the study and divided into two groups with 15 patients each based on convenient sampling method. Group A patients received mobilization with movement and Group B patients received end range mobilization for three weeks. The outcome measurements were SPADI, Functional hand to back scale, abduction range of motion using goniometer and VAS. Results: The mean values of all parameters showed significant differences in group A as compared to group B in terms of decreased pain, increased abduction range and other outcome measures. Conclusion: Based on the results it has been concluded that treating the type 1 diabetic patient with frozen shoulder, mobilization with movement exercise shows better results than end range mobilization in reducing pain and increase functional activities and mobility in frozen shoulder.

A COMPARISON OF TWO METHODS FOR MEASUREMENT OF ALDOSTERONE SECRETION RATE IN MAN

1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa
Keyword(s):  
Urinary Excretion ◽  
Normal Subjects ◽  
Secretion Rate ◽  
Aldosterone Secretion ◽  
Simple Method ◽  
Mean Values ◽  
Pathological Conditions ◽  
Significant Difference ◽  
Derivative Method ◽  
The Mean

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.

EFFECT OF OESTRONE-PELLET IMPLANTATION ON PLASMA LEVELS OF PROLACTIN

1970 ◽  
Vol 64 (2) ◽  
pp. 265-272 ◽  
Author(s):  
A. A. van der Gugten ◽  
M. Sala ◽  
H. G. Kwa
Keyword(s):  
Plasma Levels ◽  
Male Rats ◽  
Mean Values ◽  
The Mean ◽  
Dose Levels ◽  
Higher Doses ◽  
Primary Break

ABSTRACT Eight female and eight male rats were castrated at the age of 8 to 10 weeks. Four spayed and four orchidectomized rats received one oestrone/cholesterol pellet (200 μg oestrone) on the day of operation (day 0), a second pellet on day 11 and a third on day 23. The remaining animals received four oestrone/cholesterol pellets at these times. The fluctuations in the prolactin levels in the circulation induced by the oestrogen challenges in these animals were followed during 31 days by radioimmunoassays performed on days 3, 7, 9, 14, 15, 17, 23, 24, 25, 28 and 31. The results suggested that the homoeostatic mechanism regulating plasma levels of prolactin was capable of withstanding the three time-spaced oestrogen challenges only in the spayed animals receiving the lower doses of oestrogen, since it allowed the mean values of the prolactin levels to remain fairly constant during the first 4 weeks. The levels in this group rose to much higher levels only on day 31. The higher doses of oestrone in the spayed rats and both dose levels of oestrone in the orchidectomized animals apparently resulted in a primary break-down of the homoeostatic mechanism, since the prolactin levels in the animals of these groups rose to much higher levels either on day 7 or on day 9. This was followed by a period during which the prolactin levels appeared to be more or less under control, until a second and probably definitive failure of the homoeostatic mechanism allowed the mean levels to rise sharply again.

CHROMATOGRAPHY OF THE 17-KETOGENIC STEROIDS IN THE DIAGNOSIS AND CONTROL OF CONGENITAL ADRENAL HYPERPLASIA

1960 ◽  
Vol XXXIII (II) ◽  
pp. 230-250 ◽  
Author(s):  
Eileen E. Hill
Keyword(s):  
Congenital Adrenal Hyperplasia ◽  
List Type ◽  
Adrenal Hyperplasia ◽  
Normal Children ◽  
Paediatric Practice ◽  
The Mean ◽  
Cortisone Therapy ◽  
And Control ◽  
Clinical Problems ◽  
Stimulation Of

ABSTRACT A method for the fractionation of the urinary 17-ketogenic steroids with no oxygen grouping at C11 and those oxygenated at C11, is applied to the clinical problems of congenital adrenal hyperplasia. In normal children the mean ratio of the non-oxygenated to oxygenated steroids is 0.24. In childrern with congenital adrenal hyperplasia the ratio is 2.3. The reason for this difference in ratio is discussed. The changes in ratio found under stimulation of the adrenal gland with exogenous or endogenous corticotrophin and the suppression with cortisone therapy are studied. This test can be applied to isolated samples of urine, a major advantage in paediatric practice, and can be carried out in routine laboratories. It is found to be reliable in the diagnosis and sensitive in the control of congenital adrenal hyperplasia.

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