Breakdown of accommodation in nerve: a possible role for persistent sodium current.
BACKGROUND
Accommodation and breakdown of accommodation are important elements of information processing in nerve fibers, as they determine how nerve fibers react to natural slowly changing stimuli or electrical stimulation. The aim of the present study was to elucidate the biophysical mechanism of breakdown of accommodation, which at present is unknown.


RESULTS
A model of a space-clamped motor nerve fiber was developed. It was found that this new model could reproduce breakdown of accommodation when it included a low-threshold, rapidly activating, persistent sodium current. However, the phenomenon was not reproduced when the persistent sodium current did not have fast activation kinetics or a low activation threshold.


CONCLUSIONS
The present modeling study suggests that persistent, low-threshold, rapidly activating sodium currents have a key role in breakdown of accommodation, and that breakdown of accommodation can be used as a tool for studying persistent sodium current under normal and pathological conditions.
Hennings
Kristian
K
Center for Sensory-Motor Interaction (SMI), Aalborg University, Frederik Bajers Vej D3-203, 9220 Aalborg Ø, Denmark. krist@hst.auc.dk
Arendt-Nielsen
Lars
L
Andersen
Ole K
OK
D000818:Animals; D002415:Cats; D006801:Humans; D008954:Models, Biological; D009046:Motor Neurons / Q000378:metabolism*; D015203:Reproducibility of Results; D015222:Sodium Channels / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism
D015222:Sodium Channels