scholarly journals Interactions within and between parallel parietal-frontal networks involved in complex motor behaviors in prosimian galagos and a squirrel monkey

2020 ◽  
Vol 123 (1) ◽  
pp. 34-56
Author(s):  
Iwona Stepniewska ◽  
Robert M. Friedman ◽  
Daniel J. Miller ◽  
Jon H. Kaas
Keyword(s):  
Functional Domain ◽  
Simultaneous Stimulation ◽  
Motor Behaviors ◽  
Electrical Pulses ◽  
Specific Complex ◽  
Complex Motor ◽  
Motor Outputs ◽  
Parietal Cortices ◽  
Complex Movement ◽  
Stimulation Of

Long-train intracortical microstimulation (ICMS) of motor (M1) and posterior parietal cortices (PPC) in primates reveals cortical domains for different ethologically relevant behaviors. How functional domains interact with each other in producing motor behaviors is not known. In this study, we tested our hypothesis that matching domains interact to produce a specific complex movement, whereas connections between nonmatching domains are involved in suppression of conflicting motor outputs to prevent competing movements. In anesthetized galagos, we used 500-ms trains of ICMS to evoke complex movements from a functional domain in M1 or PPC while simultaneously stimulating another mismatched or matched domain. We considered movements of different and similar directions evoked from chosen cortical sites distant or close to each other. Their trajectories and speeds were analyzed and compared with those evoked by simultaneous stimulation. Stimulation of two sites evoking same or complementary movements produced a similar but more pronounced movement or a combined movement, respectively. Stimulation of two sites representing movements of different directions resulted in partial or total suppression of one of these movements. Thus interactions between domains in M1 and PPC were additive when they were functionally matched across fields or antagonistic between functionally conflicting domains, especially in PPC, suggesting that mismatched domains are involved in mutual suppression. Simultaneous stimulation of unrelated domains (forelimb and face) produced both movements independently. Movements produced by the simultaneous stimulation of sites in domains of two cerebral hemispheres were largely independent, but some interactions were observed. NEW & NOTEWORTHY Long trains of electrical pulses applied simultaneously to two sites in motor cortical areas (M1, PPC) have shown that interactions of functionally matched domains (evoking similar movements) within these areas were additive to produce a specific complex movement. Interactions between functionally mismatched domains (evoking different movements) were mostly antagonistic, suggesting their involvement in mutual suppression of conflicting motor outputs to prevent competing movements. Simultaneous stimulation of unrelated domains (forelimb and face) produced both movements independently.

scholarly journals Turnover of protein-bound serine phosphate in respiring slices of guinea-pig cerebral cortex. Effects of putative transmitters, tetrodotoxin and other agents

1973 ◽  
Vol 132 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Martin Reddington ◽  
Richard Rodnight ◽  
Michael Williams
Keyword(s):  
Cerebral Cortex ◽  
Cyclic Amp ◽  
Guinea Pig ◽  
Electrical Pulses ◽  
Phosphorus Turnover ◽  
Serine Phosphate ◽  
Stimulation Of

1. The effect of various agents on the turnover of protein-bound phosphorus in respiring slices of cerebral cortex was studied. 2. Confirming previous work turnover was increased by the application of electrical pulses for 10s to the tissue. 3. Turnover was also increased by exposure of the slices for 10min to noradrenaline (0.5mm), 5-hydroxytryptamine (1μm) and histamine (0.1mm). 4. When slices were stimulated by electrical pulses in the presence of histamine the increase in turnover was the sum of the responses given by each agent above, suggesting that different phosphorylating systems were involved. 5. Tetrodotoxin (0.5μm) blocked the increased turnover due to electrical pulses, but not that due to histamine. Tetrodotoxin also prevented the increase in tissue cyclic AMP content caused by the application of electrical pulses. 6. Phosphoprotein turnover was not affected by adenosine, despite the increase in tissue cyclic AMP content given by this agent. 7. Adenosine blocked the phosphoprotein response to histamine, but did not affect the response to electrical pulses. 8. The results are discussed in relation to the hypothesis that the stimulation of protein phosphorus turnover by electrical pulses is secondary to the release of cyclic AMP in the tissue.

The Different Connections and Motor Outputs of Lateral and Medial Giant Fibres in the Crayfish

1971 ◽  
Vol 54 (2) ◽  
pp. 391-404
Author(s):  
JAMES L. LARIMER ◽  
ALAN C. EGGLESTON ◽  
LEONA M. MASUKAWA ◽  
DONALD KENNEDY
Keyword(s):  
High Speed ◽  
Motor Neurone ◽  
Giant Axons ◽  
Procion Yellow ◽  
High Speed Cinematography ◽  
Motor Neurones ◽  
Motor Outputs ◽  
Giant Fibres ◽  
Tonic System ◽  
Stimulation Of

1. High-speed cinematography was used to analyse the abdominal movements of crayfish in response to separate stimulation of medial and lateral giant axons. These films showed that the medial giant fibres command complete abdominal flexions with little flaring of the tail appendages. The lateral giants, in contrast, evoked a relatively weak flexion of the middle abdominal segments, accompanied by promotion of the exopodites of the uropods. 2. An examination of the muscles activated by the two types of giant fibres shows that differences in the connexions between the giant fibres and specific motor neurones can account for the behavioural differences observed. 3. The output of the giant fibres was determined in the sixth abdominal ganglion, where their differential effects are most pronounced. The medial giants activate motor neurones whose axons emerge from root 6 of the sixth ganglion. The lateral giants activate motor neurones whose axons emerge via roots 2 and 3, as well as those emerging via root 6. 4. The larger motor neurones associated with the giant axons in the sixth root of the sixth ganglion have been mapped by Procion Yellow injection, and the terminations of the central giant axons in the sixth ganglion have also been determined. The connexions revealed by this technique are consistent with the physiological findings. 5. The evidence suggests that root 6 of the sixth ganglion is homologous with root 3 of the more anterior ganglia. However, the giant motor neurone of the sixth ganglion has not been identified. 6. The medial and lateral giant fibres, and perhaps other specific ‘command’ interneurones, can thus drive specific ensembles of phasic motor neurones to provide a range of stereotyped quick movements. In this respect the organization of the phasic system of interneurones and motor neurones resembles that in the tonic system.

A method for selective stimulation of leg chemoreceptors in whole crustaceans

2021 ◽  
Author(s):  
Paolo Solari ◽  
Giorgia Sollai ◽  
Francesco Palmas ◽  
Andrea Sabatini ◽  
Roberto Crnjar
Keyword(s):  
Procambarus Clarkii ◽  
Sensory Information ◽  
Natural Conditions ◽  
Search Behaviour ◽  
Non Invasive ◽  
Animal Survival ◽  
Sensory Motor ◽  
Reflex Activation ◽  
Motor Outputs ◽  
Stimulation Of

The integration of sensory information with adequate motor outputs is critical for animal survival. Here, we present an innovative technique based on a non-invasive closed-circuit device consisting of a perfusion/stimulation chamber chronically applied on a single leg of the crayfish Procambarus clarkii. Using this technique, we focally stimulated the leg inside the chamber and studied the leg-dependent sensory-motor integration involving other sensory appendages, such as antennules and maxillipeds, which remain unstimulated outside the chamber. Results show that the stimulation of a single leg with chemicals, such as disaccharides, is sufficient to trigger a complex search behaviour involving locomotion coupled with the reflex activation of antennules and maxillipeds. This technique can be easily adapted to other decapods and/or other sensory appendages. Thus, it has opened possibilities for studying sensory-motor integration evoked by leg stimulation in whole aquatic animals under natural conditions to supplement, with a direct approach, current ablation/silencing techniques.

scholarly journals Reflex cardiorespiratory events from esophageal origin are heightened by preterm birth

2017 ◽  
Vol 123 (2) ◽  
pp. 489-497 ◽  
Author(s):  
Stéphanie Nault ◽  
Nathalie Samson ◽  
Charlène Nadeau ◽  
Djamal Djeddi ◽  
Jean-Paul Praud
Keyword(s):  
Preterm Birth ◽  
Arterial Pressure ◽  
Random Order ◽  
Neonatal Infection ◽  
Full Term ◽  
Simultaneous Stimulation ◽  
C Fibers ◽  
C Fiber ◽  
Cardiorespiratory Reflexes ◽  
Stimulation Of

The involvement of gastroesophageal refluxes in cardiorespiratory events of preterm infants remains controversial. While a few studies in full-term newborn animals have shown that stimulation of esophageal receptors leads to cardiorespiratory reflexes, the latter remain largely unknown, especially after premature birth. The present study aimed to 1) characterize the cardiorespiratory reflexes originating from esophageal receptors in newborn lambs and 2) test the hypotheses that preterm birth enhances reflex cardiorespiratory inhibition and that C-fibers are involved in these reflexes. Eight full-term lambs and 10 lambs born 14 days prematurely were studied. Following surgical instrumentation, a 6-h polysomnography was performed without sedation to record electrocardiogram, respiratory movements, arterial pressure, laryngeal constrictor muscle activity, state of alertness, and hemoglobin oxygen saturation. Five esophageal stimulations of the upper and/or lower esophagus, including rapid balloon inflation and/or HCl injection, were performed in random order. A second recording was performed in full-term lambs 24 h later, after C-fiber blockade by capsaicin. Results confirmed that esophageal stimulations induced inhibitory cardiorespiratory reflexes combined with protective mechanisms, including laryngeal closure, swallowing, coughing, increased arterial pressure, and arousal. Preterm birth heightened cardiorespiratory inhibition. The strongest cardiorespiratory inhibition was observed following simultaneous stimulation of the lower and upper esophagus. Finally, cardiorespiratory inhibition was decreased after C-fiber blockade. In conclusion, esophageal stimulation induces inhibitory cardiorespiratory reflexes, which are partly mediated by C-fibers and more pronounced in preterm lambs. Clinical relevance of these findings requires further studies, especially in conditions associated with increased cardiorespiratory events, e.g., neonatal infection. NEW & NOTEWORTHY Preterm birth heightens the cardiorespiratory events triggered by esophageal stimulation. The most extensive cardiorespiratory events are induced by simultaneous stimulation of the proximal and distal esophagus.

scholarly journals Nervous rhythm arising from rivalry of antagonistic reflexes: Reflex stepping as outcome of double reciprocal innervation

1913 ◽  
Vol 86 (587) ◽  
pp. 233-261 ◽  
Keyword(s):  
Afferent Nerve ◽  
The Other ◽  
Present Communication ◽  
Simultaneous Stimulation ◽  
Afferent Nerves ◽  
Wide Range ◽  
Contralateral Muscle ◽  
Stimulation Of

The observations with which the present communication deals were met with in experiments continuing those on reciprocal innervation of symmetrical muscles. In my previous paper on that subject it had been reported that in regard to symmetrical extensors of the knee the ratio borne by intensity of the ipsilateral inhibition to the contralateral excitation is such that with equal stimuli to right and left symmetrical afferent nerves there is inhibitory suppression of contraction in both the muscles. In other words, under double reciprocal innervation the ipsilateral inhibition by each nerve completely overcomes the contralateral excitation of the other. It was shown that this mutual suppression holds over a wide range of the scale of intensities of stimulation. It was also shown that with quite weak stimuli a simultaneous stimulation of both nerves, stimuli being equal in intensity, often results in concurrent contraction of both muscles. Indeed, with quite weak stimuli, the effect of stimulation of each afferent nerve by itself is, in the decerebrate preparation, usually contraction of the ipsilateral as well as of the contralateral muscle. This being so, it is evident that at some point in the scale of intensities of stimulation there should be a place below which contralateral excitation is stronger than ipsilateral inhibition, whereas above it ipsilateral inhibition is stronger than contralateral excitation.

A Model of Temporal Scaling Correctly Predicts that Weber′s Law is Speed-dependent

2017 ◽  
Author(s):  
Nicholas F Hardy ◽  
Vishwa Goudar ◽  
Juan L Romero-Sosa ◽  
Dean Buonomano
Keyword(s):  
Neural Network ◽  
General Feature ◽  
Motor Timing ◽  
Motor Patterns ◽  
Temporal Scaling ◽  
Temporal Precision ◽  
Motor Behaviors ◽  
Morse Code ◽  
Complex Motor ◽  
Speed Effect

Timing is fundamental to complex motor behaviors: from tying a knot to playing the piano. A general feature of motor timing is temporal scaling: the ability to produce motor patterns at different speeds. Here we report that temporal scaling is not automatic. After learning to produce a Morse code pattern at one speed, subjects did not accurately generalize to novel speeds. Temporal scaling was also not a general property of a recurrent neural network (RNN) model, however after training across different speeds the model produced robust temporal scaling. The model captured a signature of motor timing-Weber′s law-but predicted that temporal precision increases at faster speeds. A human psychophysics study confirmed this prediction: the standard deviation of responses in absolute time were lower at faster speeds. These results establish that RNNs can account for temporal scaling, and suggest a novel psychophysical principle: the Weber-speed effect.

Evolution of Frequency Composition for Atrial Arrhythmias

2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Ahmad, A. ◽  
Buyamin, S. ◽  
Tuan, J. H. ◽  
G. Andre´ Ng ◽  
Schlindwein, F. S.
Keyword(s):  
United States Of America ◽  
Cardiac Arrhythmias ◽  
The United States ◽  
Dominant Frequency ◽  
Frequency Increase ◽  
Electrical Pulses ◽  
Welch Method ◽  
Physiological Studies ◽  
General Frequency ◽  
Stimulation Of

In the United States of America, cardiac arrhythmias remain the leading cause of sudden death with more than 300,000 cases per year [1, 2]. The majority of sustained cardiac arrhythmias are atrial fibrillation and these contribute a major cause of stroke[3-6]. Irregular electrical pulses can be determined inside the atria. Frequency analysis is used to measure changes in the dominant frequency (DF). Welch method is used here to obtain the frequency spectrum of the signals. The 2D frequency strength plotting allows us to identify the evolution of the frequency composition of the signal with time.In physiological studies, we should see a general frequency increase during stimulation. That means the frequency at pre-stimulation should be lower than during stimulation and this should return to pre-stimulation state after simulation stops. The reason is that stimulation of the ganglia is supposed to promote atrial conduction in AF. The initiation and maintenance of AF is significantly enhanced by simultaneous parasympathetic stimulation In physiological studies, we should see a general frequency increase during stimulation. That means the frequency at pre-stimulation should be lower than during stimulation and this should return to pre-stimulation state after simulation stops. The reason is that stimulation of the ganglia is supposed to promote atrial conduction in AF. The initiation and maintenance of AF is significantly enhanced by simultaneous parasympathetic stimulation.

Sign in / Sign up

Export Citation Format

Share Document