In mammals, sensory stimuli such as touch, light, and sound are encoded by sensory organs into nerve impulses that are conveyed via the thalamus to the sensory areas of the neocortex. How sensory stimuli are perceived also depends on whether an animal is alert and pays attention to a sensory stimulus. However, little is known about the way in which attentional mechanisms work at the circuitry level of the brain.
To better understand these mechanisms, I use awake mice to study sensory processing in the mouse barrel-cortex, a part of the somatosensory cortex that receives sensory information from the whiskers. Mice depend on their whiskers to extract information from their environment such as object location, object shape, and surface texture.
Using a behavioral task developed in the Svoboda lab, I train mice to determine the position of a metal pole with their whiskers, which they learn to do with high accuracy after a couple of days. I then use optogenetics, genetically encoded Ca2+ indicators, and in vivo patch-clamp recording to tease apart the components of the barrel-cortex circuitry that are important for this object-localization task.
I am particularly interested in the role of inhibitory interneurons because they are prominent targets of neuromodulators such as acetylcholine and serotonin, substances that are thought to be strongly regulated during attention.