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Regulation of somatic firing dynamics by backpropagating dendritic spikes.
- Source :
-
Journal of physiology, Paris [J Physiol Paris] 2008 Jul-Nov; Vol. 102 (4-6), pp. 181-94. Date of Electronic Publication: 2008 Oct 17. - Publication Year :
- 2008
-
Abstract
- Pyramidal cells of the apteronotid ELL have been shown to display a characteristic mechanism of burst discharge, which has been shown to play an important role in sensory coding. This form of bursting depends on a reciprocal dendro-somatic interaction, in which discharge of a somatic spike causes a dendritic spike, which in turn contributes a dendro-somatic current flow to create a depolarizing afterpotential (DAP) in the soma. We review here our recent work showing how the timing of this DAP influences the somatic firing dynamics, and how the degree of inactivation of dendritic Na(+) currents can cause an increased delay between somatic and dendritic spikes. This ultimately allows the DAP to become more effective at increasing the excitability of the somatic spike generating mechanism. Further, this delay between dendritic and somatic spiking can be regulated by strongly hyperpolarizing GABA(B) mediated dendritic inhibition, allowing the burst dynamics to fall under synaptic regulation. In contrast, a weaker, shunting inhibition due to GABA(A) mediated dendritic inhibition can regulate the dendritic spike waveform to decrease the dendro-somatic current flow and the resulting DAP. We therefore show that the qualitative behaviour of an individual cell can depend on the degree of synaptic input, and the exact timing of events across the spatial extent of the neuron. Thus, our results serve to illustrate the complex dynamics that can be observed in cells with significant dendritic arborisation, a nearly ubiquitous adaptation amongst principal neurons.
- Subjects :
- Animals
Biophysical Phenomena
Dendrites drug effects
Electric Fish
Electric Stimulation methods
Feedback, Physiological drug effects
GABA Agents pharmacology
In Vitro Techniques
Models, Neurological
Neural Inhibition physiology
Phylogeny
Pyramidal Cells physiology
Rhombencephalon cytology
Sodium Channels drug effects
Sodium Channels physiology
Action Potentials physiology
Dendrites physiology
Feedback, Physiological physiology
Nonlinear Dynamics
Pyramidal Cells cytology
Subjects
Details
- Language :
- English
- ISSN :
- 0928-4257
- Volume :
- 102
- Issue :
- 4-6
- Database :
- MEDLINE
- Journal :
- Journal of physiology, Paris
- Publication Type :
- Academic Journal
- Accession number :
- 18984047
- Full Text :
- https://doi.org/10.1016/j.jphysparis.2008.10.011