Dendritic excitability shapes receptive field plasticity in somatosensory cortex

Shoji Komai

Division of Structural Cell Biology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, 630-0192 Nara, Japan

Dendrite is known to be the part where the various plastic events take place, such as LTP, LTD or STDP. Especially STDP is well-known phenomenon happened with dendritic excitability called backpropagating action potential, which play an important role on “coincidence detection”. Coincidence detection would be a basic process for so called “Darwinism of synapses”. The synapse used multiple times should be remained for the next information processing, which means the most used are kept while least used connections are destroyed or 'pruned' to form neural pathways.

We’ve found the dendritic excitability takes an important role on experience-depended plasticity in the real brain during critical period. Now we found the inhibition of dendritic excitability with shRNA against the dendritic voltage-gated sodium channels did not affect on shaping the receptive field in primary somatosensory cortex. This result indicates that indeed the dendritic excitability play an important role especially during the critical period. Now we are trying to see whether the dendritic excitability is also intervened in the adult neuronal plasticity, such as sensory learning or integration, by using of behavioral tools.