Figure 1.

Impact of Eating on Natural OH Cell Dynamics In Vivo

(A) A hypothesis for temporal modulation of OH cells during eating.

(B) Left: targeting scheme of GCaMP6s to OH cells for obtaining the data shown in this figure (data using alternative targeting of OH cells are shown in Figures S2C–S2F). Right: localization of injection site and path of the optical fiber. 3V, third ventricle; L, D, M, V, lateral, dorsal, medial, ventral; VMH, ventromedial hypothalamus; Arc, arcuate nucleus. Representative image of n = 5 brains.

(C) Left: recording scheme. Right: fluorescence trace during cage exploration for mice expressing GCaMP6s or eGFP in OH neurons. Typical examples of n = 5 and n = 3 mice, respectively.

(D) Fluorescence trace during introduction of food into the cage and its subsequent consumption (orange-shaded area). Food was a drop of strawberry milkshake. Typical example of n = 5 mice.

(E) Left: fluorescence trace during repeated bouts of food contact (orange-shaded areas; food is strawberry milkshake). Typical example of n = 5 mice. Right: quantification of fluorescence change during the first 2 s of consecutive food-contact bouts (means ± SEM, n = 3 mice).

(F) Fluorescence change during food licking detected with a touch sensor (food is strawberry milkshake). Typical example of n = 5 mice across eight foods shown in (H), right.

(G) Top: probability density of OH cell activity. Bottom: distribution of the bootstrap differences of the same data. Typical example of n = 3 mice.

(H) Left: peri-event plots aligned to the onset of licking bouts (dashed line). The heatmap shows individual bouts (two per mouse), and the trace below the heatmap shows the mean of trial averages from each mouse (red line; gray lines represent SEM); n = 5 mice. Right: quantification of the experiment shown on the left, for different foods. Each column shows fluorescence change during the first 4 s of a licking bout (mean signals during 3.5 to 4 s minus signal during −0.5 to 0 s, times relative to the first lick). Data are means ± SEM of n = 4 mice in each group. Left column is control (OH-eGFP mice); other columns are OH-GCaMP6s mice; for food abbreviations, see the Supplemental Experimental Procedures; fast, overnight fasted before the experiment; fed, ad libitum feeding before the experiment. All changes in OH-GCaMP6s mice were significant (p < 0.05 in one-sample t tests of response to each food, DF = 3, t > 3.4).

See also Figures S1–S3 and Movie S1.