New insights into functional organization of somatosensory cortex

In their February publication in the Proceedings of the National Academy of Sciences, researchers Taekeun Kim, Won Chan Oh, Ph.D., and Hyungbae Kwon, Ph.D., describe how they addressed this fundamental question using electrophysiological and optical approaches. The researchers used a 2-photon photolysis technique that can be performed in vivo, together with imaging, to manipulate and monitor neuronal activity at single-cell resolution. This approach -- which has only recently been developed and employed in the field -- allowed researchers to induce the formation of these specialized microcircuits with synchronous behavior in the lab. The researchers also observed that the formation of functional microcircuits was determined by the specific settings (action potentials induced by repetitive glutamate photolysis) used during stimulation. Additionally, they found the number of neurons stimulated, but not the physical distance among the neurons, was a factor in circuit formation.

Future Directions

According to Dr. Kwon, his research team will use these recently-developed techniques to study specific learning models. Understanding the process of activity-dependent circuit formation and regulation will have a significant impact on the basic and clinical scientific communities. Abnormal neuronal connectivity has been implicated in various neuropsychiatric diseases such as schizophrenia, epilepsy and autism spectrum disorders. Advancing the understanding about cellular mechanism of activity-dependent redistribution of local circuits could help in the development of novel strategies for circuit dysfunction.