Send to

Choose Destination
J Neurophysiol. 2012 Apr;107(8):2232-43. doi: 10.1152/jn.01017.2011. Epub 2012 Jan 11.

Tonic NMDA receptor-mediated current in prefrontal cortical pyramidal cells and fast-spiking interneurons.

Author information

Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA.


Tonically activated neuronal currents mediated by N-methyl-d-aspartate receptors (NMDARs) have been hypothesized to contribute to normal neuronal function as well as to neuronal pathology resulting from excessive activation of glutamate receptors (e.g., excitotoxicity). Whereas cortical excitatory cells are very vulnerable to excitotoxic insult, the data regarding resistance of inhibitory cells (or interneurons) are inconsistent. Types of neurons with more pronounced tonic NMDAR current potentially associated with the activation of extrasynaptic NMDARs could be expected to be more vulnerable to excessive activation by glutamate. In this study, we compared tonic activation of NMDARs in excitatory pyramidal cells and inhibitory fast-spiking interneurons in prefrontal cortical slices. We assessed tonic NMDAR current by measuring holding current shift as well as noise reduction following NMDAR blockade after removal of spontaneous glutamate release. In addition, we compared NMDAR miniature excitatory postsynaptic currents (EPSCs) in both cell types. We have demonstrated for the first time that tonic NMDAR currents are present in inhibitory fast-spiking interneurons. We found that the magnitude of tonic NMDAR current is similar in pyramidal cells and fast-spiking interneurons, and that quantal release of glutamate does not significantly impact tonic NMDAR current.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center