Physiology of local cortical and thalamic networks.

The basic properties of local cortical connections were extensively studied in vitro during the past decade. In these preparations, the network is generally silent and surrounding conditions are maintained unchanged. During different behaving conditions, like sleep or wake, the network conditions are variable. A major question to understand how the cerebral cortex processes information is: what does one neocortical neuron actually tell another neuron in an active network? Since different behavioral states are associated with changes in the way the cortex processes information, a second question is: how is the dialogue between cortical neurons modulated during different behavioral states? When some of the network conditions become extreme, the normal network oscillations become replaced by paroxysmal activities.

Studies of synaptic activities are performed using the most advanced electrophysiological and morphological techniques. These include the intracellular recordings in behaving animals, multiple simultaneous intracellular recordings from synaptically connected neurons in anesthetized animals, microdialysis, microstimulation, intracellular staining and 3D reconstruction of stained neurons. In addition, we are working on creation of 4 channels in vitro set up to study conditions responsible for the generation of active states by means of intracellular recordings and/or voltage-sensitive dyes. Most of obtained experimental results are tested in computational models that constitute a part of collaborative studies.

These studies are supported by Canadian Institute of Health Research, National Institute of Health (USA), Canada Foundation for Innovation.