Anxiety-like symptoms induction and decrease exploratory
activity after unpredictable sound stress
The open field test was evaluated in 1st, 7th, and 14th-day post-stress
induction or in NST group. In this apparatus it was measured
grooming (s), rearing (s), sniffing
(s), time into the peripheral zone, and number of crossings. The ST
group spent more time grooming compared with the NST group, on both the
1st and the 7th post-stress, but not on the 14th day (Fig. 3A). On day
7, the ST females spent more time in grooming behavior compared to male
ST mice (Fig. 3A). Regarding sniffing time, in the ST group it was
significantly less both in 1 and 7 days (Fig. 3B). At day
7th after stress induction female mice had a higher
reduction in the sniffing time compared to male ST mice (Fig. 3B). For
the time of rearing male and female ST mice spent less time in this
behavior at day 7th after stress when compared to NST
group (Fig. 3C). Also, female ST mice showed a difference when compared
to male ST mice presenting a lower time for rearing at day
7th post stress (Fig. 3C). When assessing the number
of crossings, we perceived a reduction in this behavior on the 7th day
only in ST female compared to NST female group and ST male mice (Fig. 3D
and 3E). Also, we demonstrated that ST mice stayed longer in the
peripheral zone compared to the NST group at the 7th-day post-stress
induction, but not on days 1 and 14 (Fig. 3F and 3G). Also, when
comparing the sex effect in the ST group, we evidenced that ST females
spent more time in the peripheral zone compared to ST males at day
7th after stress (Fig. 3F and 3G). No significant
difference was seen between groups in locomotor activity assessed by
distance traveled (data not shown). Thus, the anxiety-like symptoms
induction and decrease exploratory activity was mainly detected at
7th-day post-stress induction. Therefore, this day after stress
induction was chosen to measure the antinociceptive effect of CGRP
antagonist treatment and the other analysis (plasmatic levels of
pro-inflammatory cytokines and CGRP, and the mRNA level of some
migraine-related markers in the trigeminal ganglion).