Orbitofrontal Cortex Neurons Respond to Sound and Activate Primary Auditory Cortex Neurons.

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Sensory Processing

Background:

• Sensory environments fluctuate, requiring rapid adaptation in sensory processing for stable perception.
• Cortical changes are critical for perception, with prior studies suggesting orbitofrontal cortex (OFC) influences primary auditory cortex (A1).
• The OFC's role in audition and its pathways to A1 remained uncharacterized.

Purpose of the Study:

• To investigate the OFC's engagement in auditory processing.
• To identify the neural pathways through which the OFC influences A1.
• To determine if OFC projections modulate A1 activity and sensory coding.

Main Methods:

• Electrophysiological recordings in mice (in vitro and in vivo).
• In vitro characterization of synaptic connections between OFC axons and A1 neurons.
• Optogenetic stimulation of OFC terminals in A1 to assess their functional impact.

Main Results:

• OFC neurons exhibit responses to auditory stimuli, suggesting a role in audition.
• OFC axons project to A1 and excite both pyramidal and GABAergic neurons via glutamatergic synapses.
• Optogenetic activation of OFC projections in A1 induced short-latency neural activity and altered sound-evoked responses.

Conclusions:

• A direct glutamatergic projection from OFC to A1 exists, capable of exciting A1 neurons early in cortical processing.
• This OFC-A1 pathway can sculpt A1 receptive fields, potentially enhancing sound processing.
• The findings support a role for the OFC in adapting sensory processing to behavioral relevance and modulating auditory perception.