11–14 Feb 2020
Nordita
Europe/Stockholm timezone

Brain-state modulation of population dynamics and behavior (this talk will be streamed)

14 Feb 2020, 11:00
1h
122:026 (Nordita)

122:026

Nordita

Roslagstullsbacken 17, 106 91 Stockholm, Sweden

Speaker

Alfonso Renart

Description

During the last few years, it has become apparent that the way information is represented in sensory cortex is strongly dependent on 'brain state'. Brain states represent modes of global coordination in brain activity, and are modulated by the behavioral and neuro-modulatory state of the animal. A salient axis of variation in brain-state is the Activation/Inactivation continuum, which measures the extent to which local populations display (Inactive/Synchronized state) or not (Active/Desynchronized state) slow, global fluctuations in activity. The degree of Activation/Inactivation in the cortex strongly varies both within wakefulness, sleep, and anesthesia. I will describe how changes in cortical Activation shape the representation of sounds by populations of neurons in the rat auditory cortex during Urethane anesthesia, focusing on the coding of level intensity differences across the two ears. Using principal component analysis, we characterize the geometry of representations at the population level, showing how the signal and noise subspaces change as a function of brain-state. These subspaces tend to orthogonalize with respect to each other and to the direction modulating all neurons uniformly as the cortex becomes more desynchronized, leading to overall more accurate representations. Finally I will describe ongoing work where we seek to understand whether and how trial-by-trial changes in the degree of synchronization in auditory cortex before a pure tone is presented impacts the ability of head-fixed mice to perform frequency discrimination.

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