| Ion channels are membrane proteins that control cell permeability to specific ions. In neurons, ion channels and neurotransmitter receptors underlie the cell''s excitability and are thus responsible for signal generation and transmission. The type, properties, number, and specific cell location of the ion channel determine a neuron''s signaling properties; the reorganization of ion channels and receptors contributes to learning and memory processes. Our laboratory investigates the molecular mechanisms governing ion-channel expression in neurons. K channels regulate the excitability level of neurons, play a major role in determining their firing patterns, and thus significantly contribute to neuronal integration. The K-channel family, the most diverse of the ion channels, generates many different excitability properties. The molecular mechanisms of this diversity are important targets for regulating neuronal excitability. We combine molecular biology techniques, such as molecular cloning, in-situ hybridization, immunocytochemistry, and gene targeting, with electrophysiological methods to determine K-channel expression and function in the central nervous system. A special focus of our research are ion channels expressed in thalamic relay neurons, the cells that process all sensory information before transmitting it to the cortex, as well as in the cortical neurons that receive and process this information. Modulation of ion channels by second messenger cascades underlies changes in the thalamocortical circuit associated with global states of awareness such as sleep, wakefulness, arousal, coma, or changes in attention. We also study how changes in ion channel expression and function in thalamical and cortical neurons contributes to the establishment and plasticity of sensory cortical maps.
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