Reversal of a Walking Leg Reflex Elicited by a Muscle Receptor

1981 ◽  
Vol 90 (1) ◽  
pp. 197-203
Author(s):  
R. A. DiCAPRIO ◽  
F. CLARAC
Keyword(s):  
Carcinus Maenas ◽  
Passive Movement ◽  
Reflex Activity ◽  
Shore Crab ◽  
Central State ◽  
Muscle Receptor ◽  
State Of Activity

Passive movement of the basal (thoracic-coxal) leg joint in the shore crab Carcinus maenas normally elicits a resistance reflex in the promotor and remotor motoneurones. Remotion of the joint excites promotor moto-neurones and promotion excites remotor motoneurones. This reflex behaviour may reverse and become an assistance reflex, where movement of the joint excites the motoneurones innervating the muscle which would assist the passive movement. This reversal of reflex activity appears to be dependent upon the central state of activity of the animal.

Reflexes Mediated by Non-Impulsive Afferent Neurones of Thoracic-Coxal Muscle Receptor Organs in the Crab, Carcinus Maenas: I. Receptor Potentials and Promotor Motoneurone Responses

1980 ◽  
Vol 86 (1) ◽  
pp. 275-303
Author(s):  
A. J. CANNONE ◽  
B. M. H. BUSH
Keyword(s):  
Carcinus Maenas ◽  
Receptor Potential ◽  
Reflex Response ◽  
Shore Crab ◽  
Sensory Fibre ◽  
Muscle Receptor ◽  
Receptor Organ ◽  
Length Changes ◽  
Receptor Muscle

Address for reprints. 1. A preparation of the thoracic-coxal muscle receptor organ of the posterior leg of the shore crab, in which central synaptic efficacy of the sensori-motor reflex pathways is maintained for long periods, is described. 2. The reflex response to receptor muscle stretch commonly involves three promotor motoneurones, designated Pm1-3 in order of their recruitment. 3. Motoneurone Pm1, and less frequently Pm2 and Pm3, may be tonically active during maintained receptor length changes within the in situ length range of the receptor muscle. 4. The following observations suggest that the T rather than the S sensory fibre provides the afferent drive onto reflexly activated promotor motoneurones: selective section of the S or T sensory fibres; frequency ‘envelopes’ of individual motoneurone responses to trapezoid stretch stimuli, including features such as adaptation and velocity sensitivity of the reflex response; and the ‘hysteresis’ in the response to increasing followed by decreasing receptor length changes, with or without superimposed trapezoid stretch stimuli. 5. The initial reflex response to ramp stretch can be directly related to the complex ‘initial component’ of the T fibre receptor potential waveform. This comprises a variable spiky alpha (α) component, followed by a longer duration, more predictable beta (β) component, which depends upon stimulus parameters such as stretch velocity and the length and tension of the receptor muscle at the onset of stretch. 6. In the de-efferented receptor muscle, changes in compliance or ‘tonus’ resulting from receptor manipulation have a marked effect on the sensory, and hence reflex, response to stretch. As this would have profound implications for the functioning of this muscle receptor organ in vivo, a role for the receptor motor innervation in counteracting any such response variability seems likely.

Effects of handling during experimental procedures on stress indices in the green shore crab, Carcinus maenas (L)

2021 ◽  
Vol 54 (2) ◽  
pp. 65-85
Author(s):  
Charlotte H. Wilson ◽  
Sarah J. Nancollas ◽  
Molly L. Rivers ◽  
John I. Spicer ◽  
Iain J. McGaw
Keyword(s):  
Carcinus Maenas ◽  
Shore Crab ◽  
Stress Indices

Biochemical responses of the shore crab (Carcinus maenas) in a eutrophic and metal-contaminated coastal system (Óbidos lagoon, Portugal)

2009 ◽  
Vol 72 (5) ◽  
pp. 1471-1480 ◽  
Author(s):  
Patrícia Pereira ◽  
Hilda de Pablo ◽  
Maria Dulce Subida ◽  
Carlos Vale ◽  
Mário Pacheco
Keyword(s):  
Carcinus Maenas ◽  
Shore Crab ◽  
Coastal System ◽  
Biochemical Responses

Mechanisms of copper toxicity in the shore crab, Carcinus maenas

1992 ◽  
Vol 114 (2) ◽  
pp. 253-257 ◽  
Author(s):  
Jan Ivan Hansen ◽  
Tariq Mustafa ◽  
Michael Depledge
Keyword(s):  
Carcinus Maenas ◽  
Copper Toxicity ◽  
Shore Crab

Effect of copper on ion- and osmoregulation in the shore crab Carcinus maenas

1986 ◽  
Vol 91 (1) ◽  
pp. 69-76 ◽  
Author(s):  
P. Bjerregaard ◽  
T. Vislie
Keyword(s):  
Carcinus Maenas ◽  
Shore Crab ◽  
Effect Of Copper
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