Figure 5.

Blocking Input from the LC Reduces Behavioral State-Dependent Increase in Excitatory Drive in L5B_enh Neurons

(A) Noradrenergic axons in the forelimb region of M1 were labeled using an anti-noradrenaline transporter antibody and secondary antibody conjugated to AlexaFluor 488.

(B) Schematic representation of an L5B pyramidal neuron recording after blocking noradrenergic input from the LC.

(C) Representative voltage trace from a L5B pyramidal neuron in the absence of noradrenergic input.

(D and E) Average V_m (D) and firing rate (E) of L5B pyramidal neurons during quiet wakefulness in the absence (open symbols, n = 45) and presence (green symbols, n = 16) of noradrenergic receptor (NA-R) antagonists. Filled circles represent data from individual neurons, black bars represent mean ± SEM. Control data (Ctrl) were taken from the dataset presented in Figure 1 for comparison. Mann-Whitney U test, ^∗p < 0.017, ^∗∗p < 0.003.

(F) Average firing rate of L5B pyramidal neurons in the presence of noradrenergic receptor antagonists (n = 16) during quiet wakefulness and movement. Filled circles represent data from individual neurons.

(G) Relative distributions of L5B_supp, L5B_enh, and L5B_n-r neurons in the absence (Ctrl) and presence (NA-R antagonists, n = 16) of noradrenergic receptor antagonists. Control data (Ctrl) were taken from the dataset presented in Figure 1 for comparison. Chi-square test, ^∗∗p < 0.01.

(H) Change in average V_m (ΔV_m) during movement in the absence (Ctrl, n = 41) and presence of noradrenergic receptor antagonists (green symbols, n = 16). Control data (Ctrl) were taken from Figure 1 for comparison. Mann-Whitney U test; ns, non-significant.

(I) Probability density distributions of ΔV_m variability across the L5B pyramidal neuron population (Ctrl and NA-R antagonists), measured as the SD of the ΔV_m distributions shown in (H) (Population ΔV_m SD) using bootstrap analysis (10,000 bootstrap replicates). Black dashed line represents population ΔV_m variability distribution in control (Ctrl), and green shading represents population ΔV_m variability distribution following noradrenergic receptor blockade. Control data (Ctrl) were taken from Figure 1 for comparison. F test, ^∗p < 0.025.

(J) Average L5B pyramidal neuron V_m power in the β frequency band (12–30 Hz) during quiet wakefulness and movement in the presence (Ctrl: L5B_supp, n = 17 and L5B_enh, n = 24) and absence of noradrenergic input (NA-R antagonists, n = 16). Solid lines represent data from individual neurons, symbols represent mean ± SEM. Control data (Ctrl) were taken from Figure 3 for comparison. ^∗p < 0.05.

(K) Average rate density of compound synaptic events in L5B pyramidal neurons during quiet wakefulness (blue) and movement (red) in the absence of noradrenergic input (n = 16). Compare with Figures 3I and 3J.

See also Figures S5 and S6.