Figure 6. Kiss1^ARH Neurons Send Sparse Projections to the SCN and are Not Necessary for Circadian Clock Gene Expression in the SCN.

A) Autoradiographic images of coronal brain sections radiolabeled with a Per1 probe at ZT8 or ZT16.

B) Average SCN pixel intensity in autoradiographic films. One-way ANOVA: YFP (CT8 n = 8; CT16 n = 6), TeTx (CT8 n = 8; CT16 n = 4); F(3,24) = 5.67, p < 0.0001. Bonferroni post hoc comparison at CT8 and CT16. YFP was not different from TeTx at either time point.

C) Representative traces of Per2-luc bioluminescence rendered from time-lapsed images taken every 20 min over 6 days from control and Kiss1^ARH-silenced mice.

D) Average period (t) from 6 d of luminescence recordings comparing YFP-injected controls to Kiss1^ARH-silenced females. Student t-test, YFP n = 3, t = 17.9 ± 1.57 h; TeTx n = 3, t = 19.4 ± 0.53 h, t₍₄₎ = 1.57, p = 0.19.

E) Average amplitude for 2 d of luminescence recording (blue box in E). Student t-test, YFP n = 4, amplitude = 26.91 ± 5.36 arbitrary units; TeTx n = 6, amplitude = 27.95 ± 12.68 arbitrary units, t₍₈₎ = 0.15, p = 0.88.

F) Schematic diagram of the targeted viral injection of a conditional synaptophysin-fused-mCherry-reporter transgene into the ARH of Kiss1^cre females and the sagittal location of the ARH with respect to the SCN.

G) Kiss1^ARH fiber expression throughout the mid-rostral hypothalamus, including the SCN. Tissue was immuno-stained for the mCherry reporter (A). Scale bar, 100 mm. Abbreviations: anterior bed nucleus of the stria terminalis, aBNST; organum vasculosum lamina terminalis, OVLT; pre optic area, POA; ventral subparaventricular zone, vSPZ; suprachiasmatic nucleus, SCN; dorsal medial hypothalamus, DMH; arcuate nucleus of the hypothalamus, ARH.

See also Figures S5 and S6