About this item:

468 Views | 47 Downloads

Author Notes:

Corresponding Author: Dieter Jaeger, Department of Biology, Emory University, 1510 Clifton Rd. NE, Atlanta, GA, 30322, 404-727-3565, djaeger@emory.edu

J.H. present address: Genentech, Inc., South San Francisco, CA 94080

Subject:

Research Funding:

National Institute of Neurological Disorders and Stroke : NINDS

This work was supported by NINDS grant 5R01-NS039852 to D. Jaeger and F32 NS051020 to J.R. Edgerton.

Keywords:

  • globus pallidus
  • basal ganglia
  • sodium channel
  • synaptic
  • dendritic spike
  • synchrony
  • model
  • information theory

Dendritic sodium channels regulate network integration in globus pallidus neurons: A modeling study

Tools:

Journal Title:

Journal of Neuroscience Nursing

Volume:

Volume 30, Number 45

Publisher:

, Pages 15146-15159

Type of Work:

Article | Post-print: After Peer Review

Abstract:

The globus pallidus (GP) predominantly contains GABAergic projection neurons that occupy a central position in the indirect pathway of the basal ganglia. They have long dendrites that can extend through half the diameter of the GP in rats, potentially enabling convergence and interaction between segregated basal ganglia circuits. Because of the length and fine diameter of GP dendrites, however, it is unclear how much influence distal synapses have on spiking activity. Dendritic expression of fast voltage-dependent Na+ channels (NaF channels) can enhance the importance of distal excitatory synapses by allowing for dendritic spike initiation and by subthreshold boosting of EPSPs. Antibody labeling has demonstrated the presence of NaF channel proteins in GP dendrites but the quantitative expression density of the channels remains unknown. We built a series of 9 GP neuron models that differed only in their dendritic NaF channel expression level to assess the functional impact of this parameter. The models were all similar in their basic electrophysiological features; however, higher expression levels of dendritic NaF channels increased the relative effectiveness of distal inputs for both excitatory and inhibitory synapses, broadening the effective extent of the dendritic tree. Higher dendritic NaF channel expression also made the neurons more resistant to tonic inhibition and highly sensitive to clustered synchronous excitation. The dendritic NaF channel expression pattern may therefore be a critical determinant of convergence for both the striatopallidal and subthalamopallidal projections, while also dictating which spatiotemporal input patterns are most effective at driving GP neuron output.

Copyright information:

© 2010 the authors

Export to EndNote