Activity in developing prefrontal cortex is shaped by sleep and sensory experience

In developing rats, behavioral state exerts a profound modulatory influence on neural activity throughout the sensorimotor system, including primary motor cortex (M1). We hypothesized that similar state-dependent modulation occurs in prefrontal cortical areas with which M1 forms functional connections. Here, using 8- and 12-day-old rats cycling freely between sleep and wake, we record neural activity in M1, secondary motor cortex (M2), and medial prefrontal cortex (mPFC). At both ages in all three areas, neural activity increased during active sleep (AS) compared with wake. Also, regardless of behavioral state, neural activity in all three areas increased during periods when limbs were moving. The movement-related activity in M2 and mPFC, like that in M1, is driven by sensory feedback. Our results, which diverge from those of previous studies using anesthetized pups, demonstrate that AS-dependent modulation and sensory responsivity extend to prefrontal cortex. These findings expand the range of possible factors shaping the activity-dependent development of higher-order cortical areas.

Methods
These files consist of all data required to recreate figures and analyses from the manuscript, including: timecodes for spike-time data, spindle-burst onset data, sensory events, and behavioral states. Electrophysioloical (spike time and spindle burst) data were collected from a TDT Neural Data Acquisition System using NeuroNexus electrodes. Spike sorting was performed in Kilosort 2, and manual curation done in Phy. Behavioral data were recorded using video collected at ~100 fps and then synchronized with the electrophysiological data. Additional data (e.g., raw electrophysiological data, video files) can be requested by contacting the corresponding author of the manuscript (Lex Gómez, Ph.D., [e-mail]), although the full pre-processed dataset is terabytes of data.