Extended Data Fig. 5: Pyramidal neuron excitability in lean and obese mice on ad libitum or food restricted feeding schedules.
From: Disinhibition of the orbitofrontal cortex biases decision-making in obesity
a) Representative recordings of action potentials observed at 100pA, 300pA and 500pA current steps from lOFC pyramidal neurons of lean and obese mice on ad libitum or food restricted feeding schedules. b) Obese mice fed high-fat diet on ad libitum (n = 3) and food restricted (n = 3) weight more than lean mice on ad libitum (n = 3) and food restricted (n = 3) feeding schedule. RM Two-way ANOVA: Diet effect F (1, 8) = 34.16, p = 0.0004***, food schedule effect F (1, 8) = 12.93, p = 0.0070**, Diet × food schedule interaction F (1, 8) = 0.2985, p = 0.5997. We had an a priori that obese mice would weigh more than lean mice regardless of food schedule. Sidak’s multiple comparisons test: ad libitum lean vs obese p = 0.0039**, food restricted lean vs obese 0.0113*. Data are presented as mean values + /− SEM. c) Diet-induced obesity increased the excitability of lOFC pyramidal neurons as indicated by frequency-current (F–I) plots of number of action potentials at current injections from 0pA to 500pA of lean food restricted (n = 14 cells/3 mice), lean ad libitum (12 cells/3 mice) and obese food restricted (n = 14 cells/3 mice) and obese ad libitum (n = 12 cells/3 mice). RM 3-way ANOVA: current step effect F (20, 520) = 509.4, p < 0.0001****, diet effect: F (1, 436) = 12.28, p = 0.0005***, food schedule effect: F (1, 26) = 4.450, p = 0.0447*, current × diet interaction: F (20, 436) = 13.45, p < 0.0001****, current × food schedule interaction: F (20, 436) = 1.792, p = 0.0193*, diet × food schedule interaction: F (1, 436) = 0.1139, p = 0.7359, current × diet × food schedule interaction F (20, 436) = 0.9759, p = 0.4906. Data are presented as mean values + /− SEM. d) Diet-induced obesity (obese food restricted n = 14 cells/3mice, obese ad libitum n = 12 cells/3mice) increases the firing slope compared to lean mice (lean food restricted n = 14 cells/3mice, lean ad libitum n = 12 cells/3 mice) in both food restricted and ad libitum feeding schedules. Mean excitability slope (slope of linear regression from individual cells, x=current step y=number of action potentials) of lOFC pyramidal neurons. Two-way RM ANOVA: Diet effect: F (1, 48) = 20.85, P < 0.0001, food schedule effect: F (1, 48) = 0.9912, p = 0.3244, diet × food schedule interaction: F (1, 48) = 1.106, p = 0.2983. Based on previous excitability data we had an a priori hypothesis that obese mice would have hyperexcitable pyramidal neurons. Sidaks multiple comparisons ad libitum lean vs obese p = 0.0007***, food restricted lean vs obese p = 0.0254*. Data are presented as mean values + /− SEM. e) The resting membrane potential in lean (lean food restricted n = 14 cells/3mice, lean ad libitum n = 12 cells/3 mice) and obese mice (obese food restricted n = 14 cells/3 mice, obese ad libitum n = 12 cells/3 mice) was not altered based on food schedule. Two-way RM ANOVA: Diet effect: F (1, 48) = 6.144, p = 0.0168*, Feeding schedule effect: F (1, 48) = 0.04941, p = 0.8250, Diet × feeding schedule interaction: F (1, 48) = 0.2927, p = 0.5910. Data are presented as mean values + /− SEM.
