Conduction Velocities and Their Temperature Coefficients in Sensory Nerve Fibres of Cockroach Legs^* Available to Purchase

The cockroach-leg preparation of Pumphrey (1936) and Pringle & Wilson (1952) lends itself easily to measurements of conduction velocity in afferent nerve fibres from many of the larger mechanoreceptive sensilla of the leg. Conduction velocity is a quantity that can be measured quite precisely, and it has an important bearing on several open problems involving sensory mechanisms in insects, as well as in cellular neurophysiology more generally. One group of problems relates to the sensory transfer functions for tactile spine mechanoreceptors of Periplaneta, determined by Pringle & Wilson (1952) and Chapman & Smith (1963). Sensory transfer functions are quantitative expressions of the stimulus-response relationship, which describe some aspects of the temporal sensory code used in information transmission, and which provide useful insight in identifying component transducer mechanisms in the sensory ending. Conduction velocity is important in this context because it contributes quantitatively to the sensory code, and because it generates a quantifiable experimental artifact in the analysis of transducer mechanisms. In the present work these effects are evaluated and are shown to be small but not negligible.