Fig. 6: NPY is required for the homo- and heterosynaptic adaptations evoked by AgRP neuron activation.
From: NPY-mediated synaptic plasticity in the extended amygdala prioritizes feeding during starvation
a Approach for chemogenetic activation of AgRP neurons in NPY-WT and NPY-KO AgRPChR2/CeAChR2 mice. Representative image showing hM3Dq-mCherry expression in the ARC. b Food intake of NPY-WT mice expressing hM3Dq in AgRP neurons following i.p. injection of saline/CNO during light cycle (N = 5 animals). *p = 0.024 (two-sided paired t-test). c Summaries of connectivity rates for the AgRP→BNST circuit in NPY-WT::AgRPChR2/NPY-KO::AgRPChR2 mice with/without (hM3Dq/Ctrl) hM3Dq expression. (7/7 brain slices from 5/5 NPY-WT::AgRPChR2 animals (Ctrl/hM3Dq); 5/9 brain slices from 4/7 NPY-KO::AgRPChR2 animals (Ctrl/hM3Dq)). Representative traces from voltage-clamp recordings illustrating the ratio of BNST neurons with synaptic AgRP neuron input. Dashed blue lines indicate light pulses. *p = 0.0251 (one-sided Fisher’s exact test). d Summaries of eIPSC amplitudes and representative traces from voltage-clamp recordings of BNST neurons in NPY-WT::CeAChR2/NPY-KO::CeAChR2 mice with/without hM3Dq expression (4/5 brain slices from 4/4 NPY-WT::CeAChR2 animals (Ctrl/hM3Dq); 3/4 brain slices from 2/4 NPY-KO::CeAChR2 animals (Ctrl/hM3Dq)). *p = 0.0346 (one-sided Mann–Whitney test), *p = 0.0497 (one-sided unpaired t-test). e Summaries of eIPSC amplitudes/latencies and representative traces from voltage-clamp recordings of BNST neurons in NPY-WT::CeAChR2 mice before/after (Baseline/NPY) bath application of NPY (0.3 µM; n = 7 cells). **p = 0.0078 (one-sided Wilcoxon test), *p = 0.018 (one-sided paired t-test). f Summaries of eIPSC amplitudes/latencies and representative traces from recordings of BNST neurons in NPY-WT::CeAChR2 mice before/after (Baseline/Ahx[5-24]-NPY) bath application of the NPY2R agonist Ahx[5-24]-NPY (1 µM; n = 6 cells). *p = 0.0219, *p = 0.0109 (one-sided paired t-test). g Summary of changes in membrane potentials and representative traces from current-clamp recordings illustrating the effect of NPY on the membrane potential of NPY1R-expressing neurons in the BNST/ARC following bath application of NPY (0.3 µM; both n = 8 cells). *p = 0.0327 (two-sided unpaired t-test). Scale bar: 100 µm (a); 3 V, third ventricle. Numbers in bars indicate BNST neurons with eIPSCs in relation to all recorded neurons. Bar graphs and scatter plots represent mean ± SEM (b, e, f, g) or average connectivity rates (c). Violin plots represent median ± quartiles (d). Schematic in (a) was created with Biorender.com released under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International license.
