Figure 1.
Schematic drawings show the localization of sections used for Fos-ir neurons counting.
The grey zones represent the AON (Bregma 1.98 mm) and Pir (Bregma 0.62 mm). Abbreviations: AON, anterior olfactory nucleus; Pir, piriform cortex.
Figure 2.
Latency to find the buried food following i.c.v. injection of vehicle or NPS in mice.
Values are means ± SEM (n = 10 mice in each group). * p<0.05, ** p<0.001. Data were analyzed by one-way ANOVA and followed by Fisher's LSD test.
Figure 3.
Olfactory habituation and dishabituation test following i.c.v. injection of vehicle or NPS in mice.
A. Mice treated with vehicle exhibited significant habituation to water, dishabituation almond to vanilla, and habituation to vanilla. B. NPS at 0.1 nmol exhibited significant habituation to water, dishabituation water to almond, dishabituation almond to vanilla, and habituation to vanilla. C. NPS at 0.5 nmol exhibited significant habituation to water, dishabituation water to almond, habituation to almond, dishabituation almond to vanilla, and habituation to vanilla. D. NPS at 1 nmol exhibited significant habituation to water, dishabituation water to almond, habituation to almond, dishabituation almond to vanilla, and habituation to vanilla. E. NPS dose-dependently increased the total sniffing time spent in olfactory habituation and dishabituation tasks. Values are means ± SEM (n = 10 mice in each group). * p<0.05, ** p<0.01, *** p<0.001 for habituation; # p<0.05, ## p<0.01, ### p<0.001 for dishabituation; data were analyzed using within-group Repeated Measures ANOVA and followed by the Newman-Keuls tests. & p<0.01, && p<0.001; data were analyzed by one-way ANOVA and followed by Fisher's LSD test.
Figure 4.
Latency to find the buried food following i.c.v. injection of vehicle, NPS or [D-Val5]NPS and NPS + [D-Val5]NPS in mice.
Values are means ± SEM (n = 10 mice in each group). * p<0.05, ** p<0.001. Data were analyzed by one-way ANOVA and followed by Fisher's LSD test.
Figure 5.
Olfactory habituation and dishabituation test in mice following i.c.v. co-injection of NPS and [D-Val5]NPS.
A. The administration of 0.5 nmol NPS + 20 nmol [D-Val5]NPS exhibited significant habituation to water, and dishabituation almod to vanilla. B. The administration of 0.5 nmol NPS + 40 nmol [D-Val5]NPS exhibited significant habituation only to water. C. The administration of 0.5 nmol NPS + 40 nmol [D-Val5]NPS significantly blocked the effect of NPS in increase of the total sniffing time in olfactory habituation and dishabituation tasks. Values are means ± SEM (n = 10 mice in each group). * p<0.001 for habituation; # p<0.05 for dishabituation; data were analyzed using within-group Repeated Measures ANOVA and followed by the Newman-Keuls tests. & p<0.001, data were analyzed by one-way ANOVA and followed by Fisher's LSD test.
Figure 6.
Effects of NPS on cumulated food intake (A) and intake in periods of time (B) in fasted mice.
Vehicle, 0.5 or 1 nmol of NPS were i.c.v. administrated in mice fasted for 32 h. Values are means ± SEM (n = 10 mice in vehicle group, n = 9 mice in each NPS group). * p<0.05, ** p<0.01, *** p<0.001. Data were analyzed by one-way ANOVA and followed by Fisher's LSD test.
Figure 7.
Effects of i.c.v. injection of NPS on Fos immunoreactivity in the AON and Pir in the mouse.
A-D photomicrographs show Fos-ir neurons (black) in the AON and Pir in NPS- and vehicle-treated mice, respectively. E, F. Histograms show quantitative analysis of the number of Fos-ir neurons in the AON and Pir following NPS (n = 4 mice) and vehicle (n = 5 mice) i.c.v. injection. Values are means ± SEM. * p<0.001. Data were analyzed by independent student's t-test. Bar = 100 µm. Abbreviations: aci, anterior commissure, intrabulbar part; AON, anterior olfactory nucleus; lo, lateral olfactory tract; Pir, piriform cortex; OV, olfactory ventricle.
Figure 8.
NPS-induced Fos-ir neurons bearing NPSR in the AON and Pir.
Photomicrographs show Fos-ir neurons in the AON (A) and Pir (D) after NPS i.c.v. administration, NPSR-ir neurons in the AON (B) and Pir (E), and the co-expression of Fos-ir and NPSR-ir neurons in the AON (C) and Pir (F), respectively. Arrow (C and F) show the co-expression of Fos-ir and NPSR-ir neurons. Bar = 50 µm.
Table 1.
Number of Fos-ir neurons in the VTT, ACo and LEnt after i.c.v. injection of NPS or vehicle.