Figure 4. Loss of BMAL1 function in NAc astrocytes increases exploratory drive in mice during the day.

Both BMFL mice expressing NAc-specific GFAP-Cre or eGFP control were run through a panel of behavioral assays testing exploratory drive. (A) In the open field (OF) task, GFAP-Cre mice show an increased number of center entries relative to eGFP controls during the day (top: t₍₁₈₎ = 1.91; # p=0.07), but not during the night (bottom: t₍₂₄₎ = 1.21; p=0.24). (B) In the light-dark box test (L/D), GFAP-Cre mice spend a significantly greater percentage of time in the brightly lit chamber of the arena during the day (top: t₍₁₉₎ = 2.37; * p=0.02), but not during the night (bottom: t₍₂₃₎ = 0.09; p=0.92). (C) GFAP-Cre mice also spent significantly more time in the open arms of the elevated plus maze (EPM) during the day (top: t₍₁₈₎ = 2.35; * p=0.03), but not during the night (bottom: t₍₂₄₎ = 0.81; p=0.43). (D) Following an overnight food restriction, GFAP-Cre mice had a shorter latency to eat food in the novelty suppressed feeding (NSF) task during the day (top: t₍₂₂₎ = 1.9; # p=0.06), but not during the night (bottom: t₍₂₃₎ = 1.15; p=0.26). (E) Across the behavioral panel, Z-normalization of the 4 behavioral tasks revealed a loss of BMAL1 function in NAc astrocytes significantly increases exploratory drive behavior relative to control mice during the day (top: t₍₁₁₎ = 8.14, **** p<0.0001), but not during the night (bottom: t₍₁₂₎ = 0.34; p=0.74). White background indicates behavior run during the day (ZT 2–6). Blue background indicates behavior run during the night (ZT 14–18). Mean ± SEM; n=7–13; # p≤0.07, * p<0.05, **** p<0.0001.