This paper has online supplemental material.
Dendritic D-type potassium currents inhibit the spike afterdepolarization in rat hippocampal CA1 pyramidal neurons
Article first published online: 4 MAY 2007
The Journal of Physiology
Volume 581, Issue 1, pages 175–187, May 2007
How to Cite
Metz, A. E., Spruston, N. and Martina, M. (2007), Dendritic D-type potassium currents inhibit the spike afterdepolarization in rat hippocampal CA1 pyramidal neurons. The Journal of Physiology, 581: 175–187. doi: 10.1113/jphysiol.2006.127068
- Issue published online: 4 MAY 2007
- Article first published online: 4 MAY 2007
- (Resubmitted 19 December 2006; accepted after revision 20 February 2007; first published online 22 February 2007)
In CA1 pyramidal neurons, burst firing is correlated with hippocampally dependent behaviours and modulation of synaptic strength. One of the mechanisms underlying burst firing in these cells is the afterdepolarization (ADP) that follows each action potential. Previous work has shown that the ADP results from the interaction of several depolarizing and hyperpolarizing conductances located in the soma and the dendrites. By using patch-clamp recordings from acute rat hippocampal slices we show that D-type potassium current modulates the size of the ADP and the bursting of CA1 pyramidal neurons. Sensitivity to α-dendrotoxin suggests that Kv1-containing potassium channels mediate this current. Dual somato-dendritic recording, outside-out dendritic recordings, and focal application of dendrotoxin together indicate that the channels mediating this current are located in the apical dendrites. Thus, our data present evidence for a dendritic segregation of Kv1-like channels in CA1 pyramidal neurons and identify a novel action for these channels, showing that they inhibit action potential bursting by restricting the size of the ADP.