My lab focuses on the study of neural circuits that mediate a specific function such as sensation/perception. In the past I dealt with the circuits below or at the entry level of cortical information processing. Currently I'm focusing on the circuits at cortical level. Since cortical circuits are hard to detect, due to the charateristics of connections cortical neurons form among themselves, more rigorous research techniques are required. One approach is to sample a number of neurons to increase the probability of detection of connections. For that, my lab will use two-photon microscopy. By combining it with intracellular recording, I hope to uncover the pattern of connectivity, while tracking its function at the same time. My immediate plan is to apply this approach for mouse visual and somatosensory cortices

 

A schematic view of exprimental approach to reveal functional connectivity. Calcium signal is monitored from a number of neurons simultaneousely by two-photon imaging and an electrical activity is monitored intracellularly from a single neuron either within the imaged view (to study local connections) or outside of the view (to study long-range connections). (left image from Nature 2006)

 


 

One of the long-term goal of my lab is to study the behavior of neural circuits in behaving animals. There is always a reductionnist's advantage to carry out experiments on simpler specimen such as anaesthesized animals or brain slices. However it is also well known that the intact brain provides a very different enviornment for neural circuits to behave. For example, numerous neuromodulators are constantly secreted depending on the internal/external states of the animal and such states are very important for how  the circuits function. Therefore, in order to understand neural circuits, it is crucial to check out the working rules of neural circuits in a realistic conditions. I'm planning to use two approaches. First, use of different level of anaesthesia, to control the level of consciousness. Second, use of a behaving animal.

 

 


 

Center for Neural Science at KIST has a few line of very interesting knockout mice. Some of them clearly shows problems in thalamic functions including disturbances in the firing patterns of relay neurons and reticular neurons. By collaboration with Dr. Shin Hee-Sup, who developed these mutant mice, we are trying to figure out the problem of sensory gating, that eventually leads to uncovering the mystery of "consciousness".