Figure 4.
Modulation of olfactory abilities of fa/+ and fa/fa Zucker rats by feeding state. Each animal was successively tested in fasted (Fast., in blue) and satiated (Sat., in red) states. (A, B, D, E, F) Values are shown as medians ± interquartile range, n = 6 per group (satiated and fasted rats); per rat genotype (fa/+ and fa/fa rats); per ISO dilution. (A, B) Box graphs showing the olfactory detection index corresponding to the percentage of licks at the pure water tube normalized to the total number of licks in the experimental cage when rats were given the choice between pure water and odorized water at ISO 10−11, ISO 10−10, ISO 10−9, ISO 10−8, ISO 10−7. The mean olfactory detection indexes were significantly higher for fasted fa/+ rats compared to satiated fa/+ rats for ISO 10−8 and ISO 10−7. The mean olfactory detection indexes were significantly higher for fasted fa/fa rats compared to satiated fa/fa rats for ISO 10−9, ISO 10−8 and ISO 10−7. (C) Aversion test and aversion re-test. Bar graphs showing the olfactory detection indexes of fa/+ (gray bars) and fa/fa (white bars) rats for the aversion test (Avers. Test, D3) and re-test (Avers. re-test D9). The olfactory detection indexes for fa/+ and fa/fa rats were not significantly different and close to 100% before (at day 3) and after (at day 9) the olfactory detection test. (D–F) Box graphs showing the number of licks during the first ISO consumption in the experimental device. (D) In fasted state (Fast.), the mean number of licks during the first ISO consumption was significantly lower for fa/fa rats compared to fa/+ rats for ISO 10−11 and ISO 10−8. (E) In satiated state (Sat.), the mean number of licks during the first ISO consumption was significantly lower in fa/fa rats compared to fa/+rats for ISO 10−11 and ISO 10−9. (F) The mean number of licks during the first ISO consumption was significantly lower for fa/fa rats compared to fa/+ rats for ISO 10−11, ISO 10−10 and ISO 10−9 regardless to feeding state.