Abstract
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1.
The maximum force exerted against an isometric force transducer by 6 leeches weighing 2.6–3.7 g, as they squeezed through apertures of different widths varied inversely with aperture width.
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2.
T cells in the leech skin code for velocity of indentation, not pressure or displacement. The frequency with which T cells fire is best described by two log functions, one for low, another for fast indentations. T cells responded to indentation velocities down to 10 μms−1.
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3.
The average threshold pressure for 5 P cells was 150 kPa and for 5 N cells was 521 kPa.
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4.
We conclude from these data that when leeches explore their mechanical environment and initiate contact with external objects, the threshold pressure for N cells is rarely crossed. Of the three classes of mechanoreceptor, T cells are the main modality through which leeches obtain contact information, though P cells may occasionally be recruited for local pressure peaks.
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Carlton, T., McVean, A. The role of touch, pressure and nociceptive mechanoreceptors of the leech in unrestrained behaviour. J Comp Physiol A 177, 781–791 (1995). https://doi.org/10.1007/BF00187637
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DOI: https://doi.org/10.1007/BF00187637