Excitatory and Inhibitory Control of Inherent Contractions in the Sea Anemone Calliactis Parasitica

1974 ◽  
Vol 60 (2) ◽  
pp. 397-422
Author(s):  
I. D. MCFARLANE
Keyword(s):  
Electrical Stimulation ◽  
Circular Muscle ◽  
Muscular Activity ◽  
Pulse Frequency ◽  
Muscle Contractions ◽  
Nerve Net ◽  
Calliactis Parasitica ◽  
Muscle Groups ◽  
Contraction Cycle ◽  
Stimulation Of

1. Bursts of nerve-net activity are always followed by a contraction cycle involving parietal and circular muscle contractions in isolated preparations of Calliactis parasitica. Both muscle groups can, however, also contract in the absence of nerve-net activity. These contractions, termed inherent, seem to follow periods of reduced activity in the endodermal slow conduction system (SS2). 2. Electrical stimulation of the SS2 inhibits inherent contractions of parietal and circular muscle preparations. Electrical stimulation of the nerve net excites parietal muscles but seems to have both excitatory and inhibitory effects on circular muscles. 3. A model for control of parietal and circular muscle contractions proposes that both the nerve net and the SS2 are responsible for directing the inherent muscular activity into the observed contraction cycle. It is suggested that when the action of these antagonistic muscles is strongly opposed the SS2 pulse frequency rises, resulting in inhibition of further muscular activity.

Control of mouth opening and pharynx protrusion during feeding in the sea anemone Calliactis parasitica

1975 ◽  
Vol 63 (3) ◽  
pp. 615-626
Author(s):  
I. D. McFarlane
Keyword(s):  
Amino Acids ◽  
Electrical Stimulation ◽  
Reduced Glutathione ◽  
Mouth Opening ◽  
Pulse Frequency ◽  
Sea Anemone ◽  
Conducting System ◽  
Nerve Net ◽  
Calliactis Parasitica ◽  
Stimulation Of

1. Activity in all three known conducting systems (the nerve net, SS1, and SS2) may accompany feeding in Calliactis. The most marked response is an increase in pulse frequency in the SS2 (the endodermal slow conducting system) during mouth opening and pharynx protrusion. 2. Electrical stimulation of the SS2 at a frequency of one shock every 5 s elicits mouth opening and pharynx protrusion in the absence of food. 3. A rise in SS2 pulse frequency is also evoked by food extracts, some amino acids, and in particular by the tripeptide reduced glutathione, which produces a response at a concentration of 10(−5) M. 4. Although the SS2 is an endodermal system, the receptors involved in the response to food appear to be ectodermal. 5. The epithelium that lines the pharynx conducts SS1 pulses, but there is some evidence for polarization of conduction.

Two slow conduction systems co-ordinate shell-climbing behaviour in the sea anemone Calliactis parasitica

1976 ◽  
Vol 64 (2) ◽  
pp. 431-445
Author(s):  
I. D. McFarlane
Keyword(s):  
Electrical Stimulation ◽  
Low Frequency ◽  
Sensory Response ◽  
Pulse Interval ◽  
Nerve Net ◽  
Slow Conduction ◽  
Calliactis Parasitica ◽  
Climbing Behaviour ◽  
The Mean ◽  
Stimulation Of

1. Pulses in two slow conducting systems, the ectodermal SS 1 and the endodermal SS 2, were recorded during shell-climbing behaviour. The mean pulse interval of SS 1 pulses was 7–4 s and that of SS 2 pulses was 6-4 s. Activity in both systems may arise as a sensory response of tentacles to shell contact, but the SS 1 and SS 2 may not share the same receptors. 2. Electrical stimulation of the SS 1 and SS 2 together, at a frequency of 1 shock every 5 s, elicits shell-climbing behaviour in the absence of a shell. 3. Low-frequency nerve-net activity (about 1 pulse every 15 s) accompanies column bending during both normal and electrically elicited responses. This activity probably arises as a result of column bending and is not due to a sensory response to the shell.

scholarly journals Nerve Net Pacemakers and Phases of Behaviour in the Sea Anemone Calliactis Parasitica

1983 ◽  
Vol 104 (1) ◽  
pp. 231-246
Author(s):  
IAN D. McFARLANE
Keyword(s):  
Electrical Stimulation ◽  
Pulse Number ◽  
Sea Anemone ◽  
Sea Anemones ◽  
Nerve Net ◽  
Partial Activation ◽  
Calliactis Parasitica ◽  
Slow System ◽  
Stimulation Of

Bursts of through-conducting nerve net (TCNN) pulses, 20–45 min apart, were recorded from Calliactis attached to shells. Within 15–25 min of the anemones being detached the TCNN bursts suddenly became more frequent (only 4–11 min apart). Such bursts continued for several hours if re-attachment was prevented. In an attached anemone simultaneous electrical stimulation of the TCNN and ectodermal slow system (SS1) with 20–30 shocks at one every 5 s also led to more frequent TCNN bursts, whether or not detachment took place. If, however, the anemone remained attached, the intervals between bursts returned to the normal resting duration after about 90 min. In all cases the decay of the 4–11 min interval TCNN bursts involved a reduction in pulse number, not an increase in burst interval. Partial activation of the TCNN pacemakers followed stimulation of the SS1 alone. It is suggested that in sea anemones the change from one behavioural phase to another is associated with a change in the patterned output of nerve net pacemakers.

scholarly journals Co-Ordination of Pedal-Disk Detachment in the Sea Anemone Calliactis Parasitica

1969 ◽  
Vol 51 (2) ◽  
pp. 387-396
Author(s):  
I. D. MCFARLANE
Keyword(s):  
Electrical Stimulation ◽  
Electrical Activity ◽  
Mechanical Stimulation ◽  
Average Frequency ◽  
Conduction System ◽  
Identical Stimulus ◽  
Slow Conduction ◽  
Calliactis Parasitica ◽  
Behavioural Sequence ◽  
Stimulation Of

1. Electrical activity has been recorded from the sphincter region of Calliactis parasitica during the behavioural sequence in which the anemone detaches from the substrate and attaches to a Buccinum shell. The ectodermal slow-conduction system (SS1) fires repetitively, the majority of observed pulses occurring in the period prior to detachment (a typical example is 25 SS1pulses at an average frequency of 1 pulse/7 sec.). Shell-tentacle contact is essential for stimulation of SS1activity. 2. Mechanical stimulation of the column excites the SS1, and 30 stimuli at a frequency of about one shock/5 sec. give pedal disk detachment. 3. Electrical stimulation of the ectoderm excites the SS1and about 30 stimuli at frequencies between one shock/3 sec. and one shock/9 sec. produce detachment. Detachment and the SS1 have an identical stimulus threshold. It is concluded that detachment is co-ordinated by the SS1.

Control of the Pacemaker System of the Nervenet in the Sea Anemone Calliactis Parasitica

1974 ◽  
Vol 61 (1) ◽  
pp. 129-143
Author(s):  
I. D. MCFARLANE
Keyword(s):  
Sensory Feedback ◽  
Pulse Frequency ◽  
Pulse Number ◽  
Pulse Action ◽  
Conduction System ◽  
The Body ◽  
Optimum Frequency ◽  
Nerve Net ◽  
Slow Conduction ◽  
Calliactis Parasitica

1. The rhythm of spontaneous nerve-net pulses is reset by intercalated evoked nerve-net pulses. 2. The origin of spontaneous nerve-net pulses can shift during a burst. There seem to be many potential pacemakers, widely distributed throughout the body, but apparently absent from the tentacles. 3. If a spontaneous or evoked pulse in the endodermal slow conduction system (SS 2) occurs during a burst, the nerve-net pulse intervals are increased during a 15-30 sec period following the SS 2 pulse. Additional SS 2 pulses cause a further increase in pulse intervals. 4. Nerve-net bursts are followed by a sequence of muscular contractions. The size of the contraction shown by any muscle group depends on nerve-net pulse number and frequency, the optimum frequency being different for different muscles. It is suggested that the SS 2 pulse action on nerve-net pulse frequency can significantly alter the behavioural output of nerve-net bursts. The SS 2 activity may represent sensory feedback on to the nervous pacemakers.

Sympathoadrenal system and activation of glycogenolysis during muscular activity

1985 ◽  
Vol 58 (4) ◽  
pp. 1122-1127 ◽  
Author(s):  
L. J. Cartier ◽  
P. D. Gollnick
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscular Activity ◽  
Creatine Phosphate ◽  
Stimulation Frequency ◽  
Sympathoadrenal System ◽  
Phosphate Depletion ◽  
Peak Value ◽  
Stimulation Of

Comparisons were made of the appearance of phosphorylase (PHOS) a and lactate (LA) during electrical stimulation of the gastrocnemius (GM) and soleus (SM) muscles of normal and sympathectomized (SYMPX) rats. Ten-second stimulation at 3 Hz increased PHOS a approximately fourfold in the GM of normal rats, whereafter it declined during stimulation until at 60 s it was similar to rest. The increase in PHOS a of GM from SYMPX rats after 10 s of stimulation was approximately 50% that of normal rats. Stimulation of the SM produced smaller and slower increases in PHOS a with the peak occurring after 60 s, which remained constant to 90 s. SYMPX did not alter this effect in the SM. LA production and creatine phosphate depletion in the GM were continuous throughout stimulation and uninfluenced by SYMPX. This was true for the SM with the exception of LA production being greater after SYMPX. [ATP] was unchanged by electrical stimulation. The rate and magnitude of the PHOS a appearance was a function of stimulation frequency. Reversion of PHOS to the b form after stimulation was rapid, with approximately 50% of the peak value being attained in 2.5 s, and at 5 s the values were those of rest. These data demonstrate that an intact sympathoadrenal system is not obligatory for the initiation of glycogenolysis in skeletal muscle.

scholarly journals COMBINED EXPOSURE DIRECT ELECTRICAL STIMULATION AND MECHANOTHERAPY USING “LOKOMAT” SOFTWARE OF PATIENTS WITH NEUROLOGICAL DEFICIT: A REPORT OF THREE PATIENTS

2020 ◽  
Vol 3 (4(73)) ◽  
pp. 22-25 ◽  
Author(s):  
I.A. Meshcheriagina
Keyword(s):  
Electrical Stimulation ◽  
Neurological Deficit ◽  
Nerve Trunk ◽  
Direct Electrical Stimulation ◽  
Combined Exposure ◽  
Implanted Electrodes ◽  
Muscle Groups ◽  
Stimulation Of

A technique of complex mechanotherapy exposure in patients with neurological deficit has been proposed using “Lokomat” device combined with epidural proximal stimulation ofspinal cord and epineural one of the damaged nerve trunk with implanted electrodes together with distal electrical stimulation of the muscle groups of the autonomous areas with epicutaneous leads to potentiate electrical stimulation. The technique has been used in treatment of three patients, the advantages of simultaneous performing mechanotherapy and electrical stimulation have been revealed

Excitatory Actions of Antho-RFamide, An Anthozoan Neuropeptide, on Muscles and Conducting Systems in the Sea Anemone Calliactis Parasitica

1987 ◽  
Vol 133 (1) ◽  
pp. 157-168 ◽  
Author(s):  
I. D. McFARLANE ◽  
D. GRAFF ◽  
C. J.P. GRIMMELIKHUIJZEN
Keyword(s):  
Electrical Activity ◽  
Slow Muscle ◽  
Conduction System ◽  
Sea Anemone ◽  
Sea Anemones ◽  
Nerve Net ◽  
Direct Excitation ◽  
Calliactis Parasitica ◽  
Muscle Groups ◽  
Fast Muscles

In the sea anemone Calliactis parasitica endodermal application of the anthozoan neuropeptide Antho-RFamide (<Glu-Gly-Arg-Phe-amide), at a concentration of 10−6 or 10−7moll−1, caused a long-lasting increase in tone, contraction frequency and contraction amplitude in several slow muscle groups but had no effect on contractions in fast muscles. The effects were investigated further in isolated muscle preparations. Ectodermal application to whole animals had no effect on muscle contractions. Both ectodermal and endodermal application, at 10−7moll−1, raised electrical activity in an ectodermal conduction system, the SSI, but had no effect on an endodermal conduction system, the SS2. Electrical activity in the SS2 was increased by application at 10−6moll−1 to the endoderm but not to the ectoderm. The peptide had no effect on the through-conducting nerve net. It is concluded that contractions evoked by Antho-RFamide may be partly due to neuronal activity, but probably also involve direct excitation of the muscles. The diverse excitatory actions of Antho-RFamide suggest that it may be a neurotransmitter or neuromodulator in sea anemones.

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