Single CA3 pyramidal cells trigger sharp waves in vitro by exciting interneurones

by Michaël Bazelot, Maria T. Teleńczuk, Richard Miles
Abstract:
The CA3 hippocampal region generates sharp waves (SPW), a population activity associated with neuronal representations. The synaptic mechanisms responsible for the generation of these events still require clarification. Using slices maintained in an interface chamber, we found that the firing of single CA3 pyramidal cells triggers SPW like events at short latencies, similar to those for the induction of firing in interneurons. Multi-electrode records from the CA3 stratum pyramidale showed that pyramidal cells triggered events consisting of putative interneuron spikes followed by field IPSPs. SPW fields consisted of a repetition of these events at intervals of 4-8?ms. Although many properties of induced and spontaneous SPWs were similar, the triggered events tended to be initiated close to the stimulated cell. These data show that the initiation of SPWs in vitro is mediated via pyramidal cell synapses that excite interneurons. They do not indicate why interneuron firing is repeated during a SPW.
Reference:
Michaël Bazelot, Maria T. Teleńczuk, Richard Miles, 2016. Single CA3 pyramidal cells trigger sharp waves in vitro by exciting interneurones, The Journal of physiology, volume 594.
Bibtex Entry:
@article{Bazelot2016,
 abstract = {The CA3 hippocampal region generates sharp waves (SPW), a population activity associated with neuronal representations. The synaptic mechanisms responsible for the generation of these events still require clarification. Using slices maintained in an interface chamber, we found that the firing of single CA3 pyramidal cells triggers SPW like events at short latencies, similar to those for the induction of firing in interneurons. Multi-electrode records from the CA3 stratum pyramidale showed that pyramidal cells triggered events consisting of putative interneuron spikes followed by field IPSPs. SPW fields consisted of a repetition of these events at intervals of 4-8?ms. Although many properties of induced and spontaneous SPWs were similar, the triggered events tended to be initiated close to the stimulated cell. These data show that the initiation of SPWs in vitro is mediated via pyramidal cell synapses that excite interneurons. They do not indicate why interneuron firing is repeated during a SPW.},
 author = {Bazelot, Micha{"e}l
and Tele{'n}czuk, Maria T.
and Miles, Richard},
 day = {15},
 doi = {10.1113/JP271644},
 issn = {1469-7793},
 journal = {The Journal of physiology},
 language = {eng},
 month = {May},
 number = {10},
 pages = {2565--2577},
 title = {Single CA3 pyramidal cells trigger sharp waves in vitro by exciting interneurones.},
 url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4865576/pdf/emss-68523.pdf},
 volume = {594},
 year = {2016}
}