Cortical glutamatergic projection neuron types contribute to distinct functional subnetworks

Area of Science:

• Neuroscience
• Cortical Circuitry
• Neural Dynamics

Background:

• The functional organization of the cerebral cortex is not fully understood.
• Monitoring neural network dynamics across cortical areas with cell-type specificity during behavior is challenging.

Purpose of the Study:

• To investigate the real-time activity dynamics of distinct projection neuron types in the mouse dorsal cortex during various behavioral states.
• To determine how these neuron types contribute to the functional architecture of the cerebral cortex.

Main Methods:

• Combined genetic targeting for specific neuron populations (PT^Fezf2 and IT^PlxnD1) with wide-field calcium imaging.
• Monitored neural activity across dorsal cortical areas during wakeful rest, spontaneous movements, and sensory stimulation in mice.
• Utilized optogenetic inhibition to assess the behavioral impact of specific subnetwork activity.

Main Results:

• Subcortical-projecting (PT^Fezf2) and intratelencephalic-projecting (IT^PlxnD1) neurons exhibited distinct activation patterns.
• Specific subnetworks of IT^PlxnD1 and PT^Fezf2 neurons were dynamically tuned to different aspects of a naturalistic feeding behavior.
• Inhibiting these subnetworks selectively disrupted components of the feeding behavior.
• Observed projection patterns of IT^PlxnD1 and PT^Fezf2 neurons aligned with their subnetwork activation patterns.

Conclusions:

• Dynamic, projection-neuron-type-specific subnetworks are a fundamental aspect of cortical functional architecture.
• These subnetworks link microcircuit components to global brain networks, complementing the concept of columnar organization.
• Understanding these subnetworks is crucial for deciphering the cellular basis of brain function.