LC activation does not influence taste sensitivity, general arousal state, and locomotion. A, Taste sensitivity test presenting normal intake of 0.5 m sucrose in unconditioned mice. PBS or PhAc solution (0.6%) was bilaterally injected into the LC (0.2 µl/site), and the fluid intake of 0.5 m sucrose was measured. n = 4–7 for each group. B, Taste reactivity test showing normal hedonic responses to 0.5 m sucrose in unconditioned Tg mice. PBS or PhAc solution (0.6%) was bilaterally injected into the LC, and the latency for hedonic responses was measured. n = 6 for each group. C, Taste reactivity test displaying unaltered aversive responses to 0.2 mm quinine in unconditioned Tg mice. After intra-LC injection of PBS or PhAc solution (0.6%), the latency for rejection responses was measured. n = 8 for each group. D, Locomotor activity. The number of beam breaks was counted for every 10 min block. The total number of beam breaks during a 60 min test period was calculated as locomotor activity during the pretreatment (Pre; blocks −6 to −1) and after PBS treatment (blocks 1–6) and the following 0.6% PhAc treatment (blocks 7–12). n = 7 for each group. Data are presented as the mean ± SEM. Individual data points are overlaid. E–H, Placement sites of the injection needles into the LC (PBS and 0.6% PhAc) for the taste sensitivity test (E), taste reactivity test for hedonic responses (F), taste reactivity test for aversive responses (G), and locomotion test (H). The AP coordinates (in mm) are shown. Scale bar, 1 mm.