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Advanced Neurology Stress accelerates parkinsonism in rats

the St-Veh group) showed reduced ambulation on day 29 neither reserpine nor the stress protocol promoted changes
compared with that on day 19. On day 29, the St-Veh group in membrane lipid peroxidation.
exhibited increased ambulation compared with the other
groups. These data are illustrated in Figure 4. Overall, the 4. Discussion
results showed that the animals became habituated to the This study investigated whether a previous exposure
open field from the first to second observations (except for to mild stress affects the progression of parkinsonism
the animals that were subjected to the UMS protocol and induced by repeated administration of a low dose of
received vehicle treatment). Moreover, reserpine treatment reserpine. First, to determine the appropriate duration of
reduced locomotor activity only on day 29, irrespective of
the stress protocol.
3.2.3. CORT plasma levels

A two-way ANOVA revealed a significant effect of stress
on CORT levels (F [1, 36] = 46.01; P < 0.0001). However,
there were no significant effects of the treatment or of the
interaction between the treatment and stress protocol.
Tukey’s post hoc test revealed increased plasma CORT levels
in all the St groups compared with that in the respective Ctl
groups. These findings are illustrated in Figure 5. Overall,
the data showed that the UMS protocol induced increased
plasma CORT levels irrespective of treatment.
Figure 4. Effects of repeated administration of 0.1 mg/kg reserpine (Res)
3.2.4. Lipid peroxidation or vehicle (Veh) on open field behavior. Distance covered in the open field
A two-way ANOVA revealed no significant effects of arena by rats on days 19 and 29 of Experiment II. Data were expressed
as mean ± SEM. Groups (n = 10) were subjected (St) or not subjected
treatment or stress on MDA quantification. However, there (Ctl) to the UMS protocol and treated with 10 subcutaneous injections
was a significant interaction between stress and treatment of 0.1 mg/kg Res or Veh on alternate days. *P < 0.05 compared with the
(F [1, 20] = 4.8; P = 0.04). Tukey’s post hoc test revealed St-Veh group on the same observation day. P < 0.05 compared with all
#
no significant differences among the groups. These data other groups on the same observation day. P < 0.05 compared with the
&
+
are shown in Figure 6. Overall, the results indicated that same group on day 19. P < 0.05 compared with the Ctl-Veh group on
day 19 (repeated measures ANOVA with stress protocol and treatment as
main factors, followed by post hoc analysis through Tukey’s test)
Abbreviations: SEM: Standard error of mean; ANOVA: Analysis of
variance; UMS: Unpredictable mild stress.

Figure 3. Effects of repeated administration of reserpine preceded by
1 week of unpredictable mild stress (UMS) on catalepsy behavior across
the protocol. Data were expressed as mean ± SEM. Groups (n = 10) were
subjected (St) or not subjected (Ctl) to the UMS protocol and treated with Figure 5. Effects of repeated administration of 0.1 mg/kg reserpine (Res)
10 subcutaneous injections of 0.1 mg/kg reserpine (Res) or vehicle (Veh) or vehicle (Veh) on plasma corticosterone levels in rats subjected to
on alternate days. *P < 0.05 compared with St-Res and Ctl-Veh groups; P chronic unpredictable mild stress for 1 week (St) or those who remained
&
< 0.05 compared with the St-Res and St-Veh groups; P < 0.05 compared in their home cages (Ctl). Data were expressed as mean ± SEM (n = 10) in
#
with the Ctl-Res and Ctl-Veh groups (repeated measures ANOVA with all groups. *P < 0.05 compared with St and Ctl groups (two-way ANOVA
stress protocol and treatment as main factors, followed by post hoc with stress protocol and treatment as main factors)
analysis through Tukey’s test) Abbreviations: ANOVA: Analysis of variance; SEM: Standard error of
Abbreviation: SEM: Standard error of mean. mean.

Volume 3 Issue 4 (2024) 6 doi: 10.36922/an.4037