Transformation Processes in a Biological Mechano-Electrical Transducer System. Length Changes within Isolated Frog Muscle Spindle During and after Stretching

摘要

Length changes within the isolated frog muscle spindle during stretch were studied by stroboscopic photomicroscopy. It was found that the extension of the central zone closely followed the imposed stretch. No indication was found of differential length changes corresponding to the dynamic peak and decay of the receptor potential. After release of stretch the spindle returned rapidly to its resting length. It is concluded that the early period of adaptation of the spindle is not due to gross differential length changes in the different regions of the spindle. The results suggest that the elastic properties play a dominant role for the transmission of the mechanical stimulus to the sensory nerve endings and for the return of the spindle after release of stretch. (Author)