3.4. Effect of α-aminovalerophenone derivatives on CPP
The CPP paradigm was used to study the rewarding effect of five
α-aminovalerophenone derivatives. The percentages of time spent in both
compartments during the preconditioning phase of all five experiments
performed were around 50% (with no statistical differences found
between compartments), indicating a total lack of preference for either
compartment. Seven animals were withdrawn from the experiments due to an
initial preference for one of the compartments (>70% of
the total session time). Figure 3 shows the effects of
α-aminovalerophenone derivatives on CPP paradigm. On the test day,
one-way ANOVA revealed a significant effect of dose for all the
compounds tested ([pentedrone], (F(3.51)=8.819);
[N-ethyl-pentedrone], (F(3.49)=5.044);
[N,N-diethyl-pentedrone], (F(3.49)=2.802);
[α-PVP], (F(3.52)=4.555); [α-PpVP],
(F(3.52)=4.179)).
Particularly, animals conditioned with pentedrone and α-PVP at 3 and 10
mg kg-1 showed a significant increase in the
preference score compared with the saline-treated animals (See Figure 3A
and 3D). Moreover, a significant increase in the preference score after
N-ethyl-pentedrone repeated administrations was observed for all doses
tested (1, 3 and 10 mg kg-1) compared to the control
group (See Figure 3B). Post hoc analysis also confirmed a significant
increase in the preference score compared to the control group, after
N,N-diethyl-pentedrone administrations, but only at a dose of 12.5 mg
kg-1 (See Figure 3C). Finally, after conditioning with
α-PpVP, post hoc analysis only revealed an increase in the preference
score at the lowest dose tested (7.5 mg kg-1) (See
Figure 3E).