Published on December 7, 2018 | Updated on January 29, 2019

CORTEX conference by Nadine Ravel

November 21st, 2012

Detecting learning-induced modulation of oscillatory activities in a neural network: a new functional imaging ?

The central question of this axis is the importance of temporal dynamics, particularly oscillatory rhythms, in information processing. By the uniqueness of its structural, anatomical, and electrical features, the olfactory system provides a good model for studying oscillatory dynamics. The olfactory stimulus occurs in a rhythmic stream (related to sniffing). During periods of active sampling, this rhythm reaches the theta frequency range. Different fast oscillatory regimes (beta, gamma) exist in a prominent way and particularly appear with the same frequency ranges both in anesthetized and awake rodent. Odor information is relayed directly to the limbic structures such as amygdala and hippocampus which play critical role in specific forms of memories. It turns out that oscillatory activities in olfactory structures and limbic areas are highly modified by learning. The active sampling in olfaction is the sniffing which is an olfactomotor act. During sniffing, important oscillatory activities appear in olfactory, somatosensory, limbic, and motor structures. These characteristics make the olfactory network a relevant model to explore neuronal computation related to brain rhythms. This makes the olfactory system a unique model to explore how oscillatory activities underlie the neural networks involved in memory function and for studying the coordination and entrainment between a sampling-imposed rhythm and a network-emerging one during a goal-directed behavior.