The brain is comprised of large networks of nerve cells. Information takes the form of electrical signals that are passed from one cell to another via synaptic connections. Each neuron receives thousands of specific excitatory and inhibitory synaptic inputs, activation of which results in fluctuations in membrane potential. Changes in membrane potential in dendrites, cell bodies and axons activate, deactivate and inactivate ionic channels in the membrane, and ultimately they are transformed into digital trains of impulses (action potentials) that propogate in an all-or-none manner along the axon to influence other neurons in the immediate vicinity and in other brain regions.
The main goal of research in our laboratory is to understand the mechanisms that control integration of synaptic inputs in the various regions of tne neuron, and to determine how the different types of ion channels contained in the cells membrane act together to control neuronal excitability. We use electrophysiological and imaging techniques to study single channels, neurons, and neural circuits in slices of living brain tissue. When called for, we perform simultaneous recording from different regions of the same neuron to obtain information on how voltage changes such as synaptic potentials and action potentials propagate within the cell. Data obtained from our recordings are also used in computer models incorporating the three dimensional structure of neurons. The models allow us to examine which aspects of neuronal structure and ion channel composition are critical in the process of synaptic integration, and to formulate testable predictions for future experiments.
The cerebral cortex is the main focus of our studies. In this most evolved of brain areas, we investigate cellular physiology both under normal and pathological conditions. We are particularly interested in the neuronal consequences of cortical hypoxia (a feature of stroke), and the basic mechanisms of epilepsy.