Researchers
in
Europe
and
the
US
wanted
to
find
out
exactly
what
happens
to
our
brain
when
we
find
ourselves
stunned
with
fright
in
the
hope
of
better
understanding
how
fear
____________________
with
human
anxiety
____________________
.
For
the
first
time
,
they
____________________
and
linked
three
parts
of
the
brain
____________________
for
freezing
behaviors
:
the
amygdala
,
____________________
periaqueductal
grey
region
and
magnocellular
nucleus
.
Mice
are
excellent
lab
animals
where
it
comes
to
anxiety
and
fear
experiments
.
When
a
mouse
is
scared
,
its
defensive
behaviors
range
from
freezing
,
attacking
,
____________________
assessment
or
fleeing
the
scene
.
How
a
mouse
acts
depends
on
variables
such
as
access
to
escape
routes
or
the
level
of
threat
faced
.
So
Andreas
Lüthi
at
the
Friedrich
Miescher
Institute
for
Biomedical
Research
in
Switzerland
and
colleagues
from
Europe
and
the
US
observed
brain
activity
in
mice
placed
in
frightening
situations
to
____________________
the
brain
circuits
____________________
for
freezing
behaviors
.
In
particular
,
the
researchers
wanted
to
learn
more
about
a
part
of
the
brain
called
the
ventrolateral
periaqueductal
grey
region
,
which
was
believed
to
____________________
some
part
in
a
mouse's
____________________
to
freeze
or
flee
.
