Figure 2.

Food and satiety hormones alter activity in DRN^SERT → LH axonal terminals and 5HT levels in LH. (A) Schematic and representative image of GCaMP7s expressing DRN^SERT soma and optic fiber placement above DRN. (B,C) Average fiber photometry traces of DRN GCaMP7s activity in response to chow food and object presentation under fasting condition (B) and quantification of mean signals (C). (D,E) Same as in (B,C) except GCaMP7s response to intraperitoneal (i.p.) injection of saline or a cocktail of satiety hormones (3 μg/kg CCK, 10 μg/kg PYY, 10 μg/kg Amylin) were measured under fasting condition. (F–J) Same as (A–E) except, DRN^SERT neurons were transduced with AxonGCaMP6s and fiber was placed on LH. (K) Schematic of in vivo 5HT measurement and representative image of 5HT_2h sensor expression in LH. (L,M) Average fiber photometry trace of 5HT levels in LH in response to chow food and object presentation under fasting condition (L) and quantification of mean 5HT_2h signal (M). (N,O) Same as in (B,C) except 5HT_2h response to intraperitoneal (i.p.) injection of saline or a cocktail of satiety hormones (3 μg/kg CCK, 10 μg/kg PYY, 10 μg/kg Amylin) were measured under fasting condition. (FT, fiber track, yellow dashed line, N = 4–6 mice/group, ∗p < 0.05, Student's t-test, scale: 300 μm). . (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)