Sustained Activation of PV+ Interneurons in Core Auditory Cortex Enables Robust Divisive Gain Control for Complex and...

Area of Science:

• Neuroscience
• Computational Neuroscience
• Auditory Neuroscience

Background:

• Sensory cortices require flexible adaptation to internal states and external demands.
• Inhibitory interneurons play a key role in modulating neural activity for processing.
• Previous studies focused on short-timescale effects of interneuron modulation.

Purpose of the Study:

• To investigate the long-timescale effects of sustained inhibitory interneuron modulation on auditory cortical processing.
• To understand the computational role of parvalbumin-positive interneuron modulation in sensory representation.

Main Methods:

• Sustained, network-wide optogenetic activation of parvalbumin-positive interneurons.
• Analysis of auditory cortical neuron responses to transient, prolonged, and naturalistic stimuli.
• Recurrent network modeling with power-law input-output functions.

Main Results:

• Auditory cortical neurons exhibited conserved spectral and temporal tuning despite reduced network activity.
• The reduction in activity was primarily divisive and consistent across various stimulus types.
• A computational model successfully replicated these findings.

Conclusions:

• Modulation of parvalbumin-positive interneurons provides robust divisive gain control.
• This mechanism operates on timescales relevant to sustained neuromodulation.
• It allows for the conservation of stimulus representations during altered network activity.