...) to the bath. Na + currents were isolated by subtracting the K + current (I K ) from total membrane currents. To block all inward current activated by a brief pulse to 0 mV, 200 nmol l -1 TTX was added. In our hands, TTX subtraction was adequate for studying time points prior to and including peak Na...

... and on voltage-sensitive Na + channels from this scorpion. * Author for correspondence (e-mail: [email protected] ) 18 06 1998 25 08 1998 © The Company of Biologists Limited 1998 toxin peptide K + current Na + current Ca 2+ current crayfish scorpion muscle fibre...

...-polarity effect on the majority of LFS siphon motoneurons, causing a transient depolarization followed by a prolonged hyperpolarization. FMRFamide induces this response in LFS neurons by causing an increase in multiple ionic currents, including a transient Na + current, a slow prolonged Na + current, a 4...

...J. David Spafford; Nikita G. Grigoriev; Andrew N. Spencer ABSTRACT The Na + current of ‘swimming motor neurones’ in the hydromedusan Polyorchis penicillatus was tetrodotoxin-insensitive. The local anaesthetics lidocaine and procainamide caused partial, non use-dependent blockade of the Na + channel...

... fitted by a single Boltzmann distribution for potentials more negative than –70mV, indicating more than one process of inactivation. The half-times of activation and of inactivation of the Na + current were voltagedependent, strongly decreasing with increasing pulse amplitude. The time courses of both...