[14p-A409-1~8] Science of Ensemble Phenomenon ~Emergence of Novel Functions and Applications by Harmonization of Complex-States~

▲ [14p-A409-5] Dynamic, task-dependent tuning of the mouse olfactory system

〇Izumi Fukunaga¹ (1.OIST Graduate Univ.)

Keywords:Neuroscience

The ability of sensory systems to dynamically tune stimulus representations is a powerful mechanism by which the brain copes with ever-changing environmental and behavioural demands. We make use of unique advantages provided by the primary olfactory region, the olfactory bulb (OB), to investigate mechanisms that underlie dynamic tuning of sensory processing in the mouse. Using chronic two-photon imaging we analyse olfactory responses of OB output neurons and glomerular-layer interneurons as mice perform coarse and fine olfactory discriminations - two tasks with opposing demands on optimal stimulus representations. By following the activity of the same set of cells, as well as presenting the same stimulus and reward in both cases, we isolate the influence of behavioural tasks on OB neurons. By training mice to rapidly switch between tasks, we demonstrate that this change occurs dynamically and reproducibly. This change is stimulus-dependent, occurs to adjust the sparseness of the OB, and is drive by the olfactory cortex. Altogether, our results show that sensory processing in the OB is dynamic, and that it decorrelates stimulus representations through sparsening and selective amplification in a demand-specific way.