Top-down prediction signals from the medial prefrontal cortex govern auditory cortex prediction errors.

Area of Science:

• Neuroscience
• Computational Neuroscience
• Auditory Processing

Background:

• The brain predicts environmental stimuli based on past experiences within the predictive coding framework.
• Sensory input is compared to internal models, generating prediction errors when mismatches occur.
• Prediction errors are observed sequentially in the primary auditory cortex (A1) and medial prefrontal cortex (mPFC).

Purpose of the Study:

• To investigate the role of the medial prefrontal cortex (mPFC) in generating prediction errors.
• To test if top-down predictions from the mPFC contribute to auditory prediction error generation in the A1.

Main Methods:

• Utilized optogenetics to inhibit top-down neural signals originating from the mPFC.
• Recorded neuronal activity in the primary auditory cortex (A1) during an auditory oddball paradigm.
• Compared prediction error responses to rare, predictable, and random auditory stimuli.

Main Results:

• Inhibiting top-down signals from the mPFC significantly reduced prediction errors in the A1 in response to rare sounds.
• The mPFC inhibition did not alter A1 responses to predictable or random auditory stimuli.
• This suggests a specific role for mPFC top-down predictions in processing unpredicted auditory events.

Conclusions:

• The medial prefrontal cortex (mPFC) provides top-down predictive signals that are crucial for generating auditory prediction errors.
• These findings empirically support the contribution of mPFC predictions to enhancing primary auditory cortex (A1) responses to unexpected stimuli.