After-effects following responses of a muscle stretch receptor of the shore crab, Carcinus maenas.
Stretch evoked responses of the thoracic-coxal muscle receptor organ in the crab are shown to be time dependent. Thus, by varying the interstretch interval, the duration of the T fibre dynamic component of the response to a ramp-and-hold stretch was found to be directly related to the inter-stretch interval. With long interstretch intervals (e.g. 10 min), the T fibre dynamic component of the response to stretch was undistinguishable from the response when pre-conditioned with stimulation of the receptor motor nerve. These observations are consistent with the hypothesis of spontaneous cross-bridge formation when the receptor is quiescent. Such properties lead to a source of ambiguity of the muscle afferent response, which are presumably overcome by maintaining tonic efferent activation of the receptor.
Harrison
P J
PJ
Department of Physiology, University College London, U.K.
D000818:Animals; D003386:Brachyura / Q000502:physiology*; D066298:In Vitro Techniques; D008465:Mechanoreceptors / Q000502:physiology*; D008564:Membrane Potentials; D009119:Muscle Contraction; D009132:Muscles / Q000502:physiology*; D013997:Time Factors