Mechanical responses of the body wall muscle of the earthworm, Lumbricus terrestris, to segmental nerve stimulation

1971 ◽  
Vol 49 (12) ◽  
pp. 1527-1534 ◽  
Author(s):  
Charles D. Drewes ◽  
Ralph A. Pax
Keyword(s):  
Nerve Stimulation ◽  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Lumbricus Terrestris ◽  
Repetitive Stimulation ◽  
Second Phase ◽  
Muscle Response ◽  
Mechanical Responses ◽  
Segmental Nerve ◽  
Earthworm Lumbricus

Suitable nerve–muscle preparations are described for recording the electrical and mechanical responses of the longitudinal and circular muscle to segmental nerve stimulation in the earthworm, Lumbricus terrestris. The longitudinal muscle response to prolonged repetitive stimulation consists of a smooth increase in tension to form a peak in less than 10 s followed by a slow decline in tension to about one-half peak tension in 45 s. The circular muscle response to prolonged repetitive stimulation consists of two distinct phases of tension development: an initial, rapidly developing peak resembling that in longitudinal muscle and a slow, irregularly developing second phase. The circular and longitudinal muscle responses are obtained at frequencies above f or 2/s, with the amplitude of each response being a function of the stimulus strength within a range of 0.4–1.4 V (2 ms) and the stimulus frequency within a range of 5–50/s. In addition there is a threshold-dependent inhibition of the second phase of the circular muscle response.Circular and longitudinal responses to single stimuli are obtained with stimulus strengths approximately 10 times greater than those of the responses to repetitive stimulation and the amplitude of these responses appears to be a function of the strength of stimulation. The single stimulus response appears to be a result of repetitive firing in the same motor fibers which mediate the response to repetitive stimulation.

Neuromuscular Physiology of the Longitudinal Muscle of the Earthworm, Lumbricus Terrestris

1974 ◽  
Vol 60 (2) ◽  
pp. 453-467
Author(s):  
C. D. DREWES ◽  
R. A. PAX
Keyword(s):  
Time Course ◽  
Longitudinal Muscle ◽  
Lumbricus Terrestris ◽  
Single Pulse ◽  
Repetitive Stimulation ◽  
Muscle Fibres ◽  
Mechanical Responses ◽  
Segmental Nerve ◽  
Earthworm Lumbricus ◽  
Stimulation Of

1. Patterns of innervation of the longitudinal muscle of the earthworm, Lumbricus terrestris, were examined electrophysiologically. 2. The longitudinal musculature of a segment is innervated by relatively few axons, a fast and slow axon being present in segmental nerve I and in the double nerve, segmental nerve II-III. 3. Single-pulse stimulation of the fast axon produces large external muscle potentials and small twitch-like contractions, which with repetitive stimulation are antifacilitating. 4. Repetitive stimulation of the slow axon produces large, slowly developing and sustained mechanical responses, with electrical and mechanical responses showing summation and facilitation. 5. The amplitude and time course of slow mechanical responses are related to the frequency of stimulation. 6. Individual longitudinal muscle fibres are innervated by either the fast or slow axon in a segmental nerve, or by both fast and slow axons. 7. No evidence was found for peripheral inhibitory innervation of the longitudinal muscle.

Slow Activity in the Nervous System of the Earthworm, Lumbricus Terrestris

1967 ◽  
Vol 46 (3) ◽  
pp. 571-583
Author(s):  
M. B. V. ROBERTS
Keyword(s):  
Nervous System ◽  
Nerve Cord ◽  
Action Potentials ◽  
Longitudinal Muscle ◽  
Lumbricus Terrestris ◽  
Longitudinal Contraction ◽  
Peripheral Stimulation ◽  
Segmental Nerve ◽  
Slow Potentials ◽  
Slow Activity

1. Three thresholds are demonstrated in the first segmental nerve and two (sometimes three) in the second and third segmental nerves together. 2. Slow potentials recorded from the ventral nerve cord consist of several peaks. The first peak is composed of three spikes which make their appearance at different thresholds. Transmission of at least some of the slow potentials is decremental. 3. Transmission speeds in the nerve cord and segmental nerves range from 0.4 to 0.6 m./sec. 4. Action potentials in the longitudinal muscle are recorded in response to slow potentials in the nerve cord. 5. Two slow reflexes, one involving elongation, the other longitudinal contraction, are described. The latter has the lower threshold with peripheral stimulation. 6. Slow activity in the nervous system is discussed in relation to reflex activity of the earthworm and the neurone anatomy of the nerve cord and segmental nerves.

The Giant Fibre Reflex of the Earthworm, Lumbricus Terrestris L

1962 ◽  
Vol 39 (2) ◽  
pp. 229-237
Author(s):  
M. B. V. ROBERTS
Keyword(s):  
Neuromuscular Junctions ◽  
Lumbricus Terrestris ◽  
Repetitive Stimulation ◽  
Motor Neurone ◽  
Giant Fibre ◽  
Sensory Neurones ◽  
Contractile Mechanism ◽  
Motor Neurones ◽  
Earthworm Lumbricus

1. The purpose of this investigation was to locate the site of fatigue in the giant fibre reflex of the earthworm. 2. The following sites do not show rapid fatigue on repetitive stimulation: contractile mechanism of muscle, neuromuscular junctions, junctions in the course of the motor neurone tracts. 3. Rapid failure of transmission (accommodation) occurs between the sensory neurones and the giant fibre, and between the giant fibre and the motor neurones.

Neuromuscular Physiology of the Longitudinal Muscle of the Earthworm, Lumbricus Terrestris

1974 ◽  
Vol 60 (2) ◽  
pp. 469-475
Author(s):  
C. D. DREWES ◽  
R. A. PAX
Keyword(s):  
Longitudinal Muscle ◽  
Lumbricus Terrestris ◽  
Muscle Fibres ◽  
Posterior Pair ◽  
Anterior Pair ◽  
Earthworm Lumbricus

1. The motor fields of individual segmental nerves have been mapped electrophysiologically in the longitudinal muscle of the earthworm, Lumbricus terrestris. 2. The anterior pair of segmental nerves (SNI) innervates approximately the anterior two-thirds of its segment and a small portion of the segment just anterior to it. 3. The posterior pair of segmental nerves (SNII-III) innervates approximately the posterior two-thirds of its segment and a small portion of the segment just posterior to it. 4. Adjacent nerves (both intrasegmental and intersegmental) have partially overlapping motor fields; that is, adjacent segmental nerves innervate some of the same longitudinal muscle fibres.

Stretch-sensitive neural units in the body wall of the earthworm, Lumbricus terrestris L

1976 ◽  
Vol 65 (1) ◽  
pp. 39-50
Author(s):  
C. D. Drewes ◽  
C. R. Fourtner
Keyword(s):  
Body Wall ◽  
Lumbricus Terrestris ◽  
Spike Frequency ◽  
The Body ◽  
Frequency Sensitivity ◽  
Segmental Nerve ◽  
Longitudinal Stretch ◽  
Sensory Neural ◽  
Earthworm Lumbricus

1. Sensory neural units responding to sinusoidal stretching of the body wall were studied in the earthworm, Lumbricus terrestris L. 2. A phasic stretch-sensitive unit found in segmental nerve I responded optimally to stretching at frequencies of 4-6/min. 3. The number of spikes per stretch and the spike frequency in the unit were directly related to the amplitude of the applied stretch within a range of 0-2-0-7 mm stretch/segment. 4. The ranges of amplitude and frequency sensitivity for the unit in isolated preparations corresponded closely to stretch parameters seen during peristaltic locomotion in intact animals. 5. Stretch-sensitive responses in segmental nerve II-III were more variable; some units responded to longitudinal stretch while others responded to relaxation.

scholarly journals The extracellular hemoglobin of the earthworm, Lumbricus terrestris. Determination of subunit stoichiometry

1993 ◽  
Vol 268 (18) ◽  
pp. 13539-13547 ◽  
Author(s):  
D.W. Ownby ◽  
H. Zhu ◽  
K. Schneider ◽  
R.C. Beavis ◽  
B.T. Chait ◽  
...  
Keyword(s):  
Lumbricus Terrestris ◽  
Subunit Stoichiometry ◽  
Earthworm Lumbricus

Superoxide Dismutase Activity in the Giant Hemoglobin of the Earthworm,Lumbricus terrestris

1996 ◽  
Vol 330 (2) ◽  
pp. 281-284 ◽  
Author(s):  
Stefan I. Liochev ◽  
Askar R. Kuchumov ◽  
Serge N. Vinogradov ◽  
Irwin Fridovich
Keyword(s):  
Superoxide Dismutase ◽  
Lumbricus Terrestris ◽  
Superoxide Dismutase Activity ◽  
Earthworm Lumbricus
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