Developmental maturation of millimeter-scale functional networks across brain areas

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Systems Neuroscience

Background:

• Cortical areas exhibit diverse representations, from unimodal sensory cortices to higher-order association areas.
• Early development shows commonality in distributed and modular networks across sensory and non-sensory brain regions.
• It remains unclear if this initial modular structure follows a common developmental path or persists differently across areas.

Purpose of the Study:

• To investigate the developmental trajectory of network organization across diverse cortical regions.
• To determine if modular functional organization is conserved across different brain areas during development.
• To compare network changes in primary sensory cortices and higher-order association areas.

Main Methods:

• Utilized *in vivo* widefield calcium imaging of spontaneous neural activity in ferrets.
• Examined network development over a 3-week period around eye opening.
• Analyzed changes in modular functional organization and correlated networks across visual, auditory, somatosensory, prefrontal, and parietal cortices.

Main Results:

• All examined cortical regions, including primary sensory (V1, A1, S1) and association areas, displayed similar developmental patterns.
• A modular functional organization and millimeter-scale correlated networks were present in all areas.
• These networks generally weakened with development, except for a strengthening observed in the primary visual cortex (V1).

Conclusions:

• The conserved maintenance of modular organization suggests a common developmental pathway for neural network refinement.
• Modular organization, known in visual areas, may be similarly engaged in diverse brain regions.
• Developmental changes in network organization are broadly conserved across the cortex, with notable exceptions like V1.