Using tight-seal recordings from rat spinal cord slices, intracellular
labelling and computer simulation, we analysed the mechanisms of spike
frequency adaptation in substantia gelatinosa (SG)
neurones. Adapting-firing neurones (AFNs) generated short bursts of
spikes during sustained depolarization and were mostly found in
lateral SG. ... Ca2 + -dependent conductances do not contribute to
adapting firing. Transient KA current was small and completely
inactivated at resting potential suggesting that adapting firing was
mainly generated by voltage-gated Na+ and delayed-rectifier K+ (KDR )
currents. ... Computer simulation has further revealed that
down-regulation of Na+ conductance represents an effective mechanism
for the induction of firing adaptation. It is suggested that the
cell-specific regulation of Na+ channel expression can be an important
factor underlying the diversity of firing patterns in SG neurones.
See paper for more and details.
Melnick IV, Santos SF, Safronov BV (2004) Mechanism of spike frequency adaptation in substantia gelatinosa neurones of rat. J Physiol 559:383-95 [PubMed]