| Title | Encoding and decoding bursts by NMDA spikes in basal dendrites of layer 5 pyramidal neurons. | | Author(s) | Polsky A, Mel B, Schiller J | | Institution | Department of Physiology, Technion Medical School, Haifa, Israel. | | Source | J Neurosci 2009 Sep 23; 29(38):11891-903. | | MeSH | Action Potentials
Animals
Calcium Channel Blockers
Cerebral Cortex
Computer Simulation
Dendrites
Electric Stimulation
Glutamic Acid
N-Methylaspartate
Neuronal Plasticity
Patch-Clamp Techniques
Pyramidal Cells
Rats
Rats, Wistar
Receptors, N-Methyl-D-Aspartate
Sodium Channel Blockers
Synapses
Time Factors
| | Abstract | Bursts of action potentials are important information-bearing signals in the brain, although the neuronal specializations underlying burst generation and detection are only partially understood. In apical dendrites of neocortical pyramidal neurons, calcium spikes are known to contribute to burst generation, but a comparable understanding of basal dendritic mechanisms is lacking. Here we show that NMDA spikes in basal dendrites mediate both detection and generation of bursts through a postsynaptic mechanism. High-frequency inputs to basal dendrites markedly facilitated NMDA spike initiation compared with low-frequency activation or single inputs. Unlike conventional temporal summation effects based on voltage, however, NMDA spike facilitation depended mainly on residual glutamate bound to NMDA receptors from previous activations. Once triggered by an input burst, we found that NMDA spikes in turn reliably trigger output bursts under in vivo-like stimulus conditions. Through their unique biophysical properties, NMDA spikes are thus ideally suited to promote the propagation of bursts through the cortical network. | | Language | eng | | Pub Type(s) | In Vitro
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
| | PubMed ID | 19776275 |
|
