Conduction in 50–100 mm. lengths of a mixed nerve, the peroneal, in tick paralysed dogs was investigated.
In vivo, a reduction of the gross amplitude of the action potential to half the control value was seen.
In vitro, no difference could be found in the amplitudes of the action potentials of nerves from paralysed and normal dogs. This held
whether the nerves were bathed in Locke solution or in plasma from the same dog.
The results suggest that there is a variation in the sensitivity of the nodes of Ranver to the toxin so that the longer the
length of the nerve trunk examined the greater will be the probability that an increasing number of fibres will show a block
in conduction.
This study was carried out while the first mentioned author was Professor and Head of the Department of Pharmacology, University
of Ottawa.