Adrenergic Modulation of Cortical Gain and Sensory Processing in the Mouse Visual Cortex

Area of Science:

• Neuroscience
• Sensory Perception
• Computational Neuroscience

Background:

• Sensory perception relies on neuronal activity, influenced by internal variability and external noise.
• Norepinephrine (NE) modulates neural circuits, affecting excitation-inhibition balance and connectivity.
• The precise role of NE in shaping sensory processing under noisy conditions remains unclear.

Purpose of the Study:

• Investigate how adrenergic modulation impacts signal-to-noise processing in the primary visual cortex (V1).
• Examine the effects of NE on perceptual decision-making in mice under varying visual noise levels.
• Determine the influence of NE on cortical gain control and interlaminar communication.

Main Methods:

• In vivo local field potential (LFP) recordings from V1 layers 2/3 and 4 in sedated mice.
• Systemic and intracortical administration of adrenergic drugs (atomoxetine, clonidine).
• Two-alternative forced-choice task in freely moving mice to assess visual discrimination.

Main Results:

• Moderate visual noise enhanced signal processing and choices (stochastic resonance); high noise impaired performance.
• Systemic atomoxetine disrupted cortical gain control, flattening the signal-to-noise ratio.
• Adrenergic manipulations impaired visual discrimination accuracy and increased response variability.

Conclusions:

• Norepinephrine (NE) dynamically regulates the trade-off between signal amplification and noise suppression.
• NE's effects are context- and noise-dependent, influencing perceptual decision-making.
• Findings link interlaminar communication and cortical variability to neuromodulatory control of perception.