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. Author manuscript; available in PMC: 2017 Apr 6.
Published in final edited form as: Nat Neurosci. 2016 Sep 19;19(12):1628–1635. doi: 10.1038/nn.4392

Figure 5. DMHpDYN neurons are a subset of GABAergic DMHLepR→ARC neurons.

Figure 5

(a–b), DMHpDYN neurons (red) provide monosynaptic inhibitory input to 95% of ARCAgRP (a; 20/21 connected) neurons recorded but not ARCPOMC neurons (b; 0/12 connected). (c–d), in vivo optogenetic stimulation of DMHpDYN→ARC terminals significantly reduced food consumption during the dark-cycle (c; n=3, repeated measures ANOVA, main effect of treatment (F(1,8)=77.14, p<0.0001), main effect of time (F(3,8)=21.49, p=0.0003) and interaction (F(3,8)=12.69, p=0.002) and following an overnight fast (d; n=3, repeated measures ANOVA, main effect of treatment (F(1,8)=193.60, p<0.0001), main effect of time (F(3,8)=111.90, p<0.0001) and interaction (F(3,8)=22.63, p=0.0003). (e–f), in vivo fiber photometry demonstrated that DMHpDYN neurons were rapidly activated upon presentation of a small chow pellet (t=0), compared to a non-food object, in a energy-state dependent manner (e, mean effects from all mice across time, n=5–6; f, mean response from 0–10s post food presentation, one-way ANOVA, F(3,18)=19.56, p<0.0001). (g), activation of DMHpDYN to small pellet availability occurred prior to the initiation of consumption and was not increased further once consumption began (n=44; repeated measures ANOVA, F(43,86)=40.61, p<0.0001). (h–i), DMHpDYN neurons were rapidly activated upon presentation of a large chow pellet, compared to a non-food object, in a energy-state dependent manner (h, mean effects from all mice across time, n=5–6; i, mean response from 0–10s post food presentation, one-way ANOVA, F(3,18)=13.43, p<0.0001). (j), calcium response of DMHpDYN neurons to large chow pellets was potentiated compared to that elicited by small chow pellets in the same mouse (n=6; paired t-test, t(5)=3.56, p=0.016). (k–l), presentation of chocolate activated DMHpDYN neurons, compared to a non-food object, and was comparable to ad libitum chow-fed mice (k, mean effects from all mice across time, n=5–6; l, mean response from 0–10s post food presentation, one-way ANOVA, F(3,18)=18.03, p<0.0001). (m), DMHpDYN neuron calcium responses to chocolate were increased compared to chow (n=6, paired t-test, t(5)=5.09, p=0.0038). All data presented as mean±SEM; post-hoc p-values: *p<0.05; **p<0.01; ***p<0.001; ****P<0.0001. Abbreviations, ΔF/F, fractional change in fluorescence.