Dr. Oxana Eschenko

My research aims at better understanding the principles of neuromodulation in the brain. Neuromodulators such as acetylcholine, dopamine, serotonin or noradrenaline regulate many visceral and cognitive functions. Neuromodulatory dysfunction often leads to various psychiatric disorders. Highly diffused efferents and volume transmission (as opposed to synaptic) are common features of many neuromodulatory systems. In contrast to their established role in controlling arousal, we are only beginning to understand the mechanisms of differentiated neuromodulation of the functionally diverse neural circuits underlying higher-order cognitive processes. Recently appreciated complexity of the structural and functional organization of evolutionary preserved neuromodulatory systems emphasized an emerging need to explore the effects of neuromodulators at different spatial and temporal scales.

In my group, we mainly focus on the noradrenergic system with its core, a brainstem nucleus Locus Coeruleus (LC). The LC neurons project extensively throughout the brain, innervating essentially all parts of the nervous system from the spinal cord to the frontal cortex. We study interactions between the LC and its diverse forebrain targets and the functional significance of such interactions. Using multi-modal methodology, we aim to characterize the LC neuromodulatory effects at different spatial and temporal scales and under different behavioral states. Specifically, we study the effects of LC activation or inactivation in multiple subcortical and cortical regions using multi-site extracellular recordings and whole-brain imaging using fMRI. We also study the consequences of the temporally and spatially precise modulation of LC activity on sensory processing, learning and memory.