Sequential and Distributed Maintenance of Information in Working Memory
Working memory is the ability to store information for short periods of time (seconds) in the absence of ongoing sensory input. While a number of brain regions vital for working memory have been identified, and persistent activity in these regions has been recorded during working memory tasks, we still do not understand the mechanisms by which an ensemble of neurons generate these ongoingactivity patterns. Furthermore, it is poorly understood how multiple regions coordinate the maintenance of memories. To gain more insight into this problem, we have trained mice to perform an olfactory working-memory task, where head-fixed mice compare the identity of two discrete odors separated by a five seconddelay period.To interrogate the evolution of neural population activity of secondary motor cortex and its relationship to working memory, we performed optogenetic silencing, electrophysiological measurements, and large-scale calcium imaging ofthe secondary motor cortex. Perturbation experiments demonstrate the necessity of secondary motor cortex activity in the late delay period. Large-scale neuronal population recordings show attractor dynamics, with each behavioral outcome corresponding to one discrete attractor. Working memory activity is mostlikely distributed across multi-regional circuits ensuring that the memory and behavior are robust to perturbations.
Location: NRB Auditorium
Date: Tuesday, November 5, 2019
Host: Felix Schweizer