GALR2 and the Y1R agonists intranasally administered increased
cell proliferation in the ventral Hippocampus
We evaluated the impact of GALR2 agonist M1145 and the Y1R agonist
intranasally co-injected on adult ventral hippocampal cell proliferation
by using the proliferating cell nuclear antigen (PCNA). M1145 and the
Y1R agonist coadministration significantly increased cell proliferation,
as demonstrated by the number of PCNA-IR cells, specifically in the
sub-granular zone (Sgz) of the dentate gyrus compared to control
(one-way ANOVA, F4,15 = 12.38, p<0.001, Newman–Keuls post-hoc
test: p<0.001) (Figure 2 a,b,d), M1145 (Newman–Keuls post-hoc
test: p<0.001) and Y1R agonist groups (Newman–Keuls post-hoc
test: p<0.05) (Figure 2 a,b,d). The addition of GALR2
antagonist M871 completely blocked the M1145 and the Y1R agonist effects
in the dentate gyrus (Newman–Keuls post-hoc test: p<0.01)
(Figure 2 b), validating the participation of GALR2 in the Y1R/GALR2
agonist interaction to stimulate cell proliferation on the ventral
hippocampus.
Moreover, the intranasal administration of the Y1R agonist alone induced
an increase in the number of PCNA positive cells in the subgranular zone
(Sgz) of the ventral hippocampus (Figure 2 a,b) compared with the
control and M1145 groups Newman-Keuls post-hoc test: p<0.05)
(Figure 2 a,b). However, the intranasal delivery of M1145 alone lacked
effects on the numbers of PCNA-IR profiles (Figure 2b) compared with the
control group (Figure 2 a–c).