Deciphering the long-range modulation of neuronal networks in auditory-guided behavior learning

Interpretation of external stimuli is essential for us to interact properly with our environment. In this context, sound is a major sensory information that takes part in social interaction but also alerts of dangers. Auditory stimuli are integrated by stereotyped neuronal circuits where inhibitory neurons play a key regulatory role.

These circuits can be modulated for example by learning which allow a better reaction in sensory-guided behaviors.

It has been recently suggested that higher-order brain areas feedbacks onto primary sensory cortices are essential in these learning processes as they modulate primary sensory circuits.

Yet, less is known about long-range circuits involved in learning processes which allows the animal to respond more precisely to auditory stimuli. The objectif of AudiLearn is to disentangle how higher-order brain areas influence auditory learning.

My working hypothesis is that long-range modulation of auditory cortex neurons is reinforced during learning in order to increase their response accuracy.

Therefore, AudiLearn aims at (i) identifying neuronal subpopulations of the primary auditory cortex that present changes of activity with learning using in-vivo electrophysiological recordings of neuronal activity in the auditory cortex and optogenetics during an auditory discrimination task in mice, (ii) detect long-range projections onto these neurons using rabies-virus based monosynaptic retrograde tracing and finally (iii) modulate these long-range presynaptic neurons with optogenetics to decipher their role in modulating sensory coding during the auditory learning process.

This project will bring a novel insight in auditory coding by identifying long-range modulators of the primary auditory cortex.

More generally, it will increase our understanding of the learning-processes that occur in sensory cortices which can be impaired in pathological conditions such as in tinnitus, autism or schizophrenia.