Mice
receive
i.p.
injection
of
physiological
saline
immediately
prior
to
open
field
test
-
Day
2
Mice
receive
second
i.p.
injection
of
physiological
saline
immediately
prior
to
open
field
test
Locomotor
activity
(see
below)
Day
3
Mice
receive
i.p.
injection
of
cocaine
immediately
prior
to
open
field
test
Locomotor
activity
(see
below)
*Supplementary
data
are
available
for
this
project.
See
Tarantino1
Equipment
and
supplies
Syringes,
needles
Open
Field
apparatus
(Med
Associates
ENV515-16,
St.
Albans
VT)
Software
(Med
Associates
Windows-based
Open
Field
Activity,
v5)
Open
Field:
17
x
17"
square
arena
with
white
Plexiglas
floor
and
clear
Plexiglas
walls
surrounded
by
infrared
beams
spaced
1"
apart
on
the
X,
Y,
and
Z-axes
to
detect
both
horizontal
and
vertical
movement.
Reagents
and
solutions
Physiological
saline
Cocaine
HCl
(Sigma-Aldrich,
St.
Louis
MO)
Acclimation
Mice
were
acclimated
at
least
10
days
prior
to
testing.
Procedure:
Locomotor
activity
in
the
Open
Field
Mice
are
tested
over
three
consecutive
days:
Day
1:
First
i.p.
injection
of
physiological
saline
in
a
volume
of
0.01
mL/g
immediately
prior
to
Open
Field
testing
(30-min
test).
Day
2:
Second
i.p.
injection
of
physiological
saline
in
a
volume
of
0.01
mL/g
immediately
prior
to
Open
Field
testing
(30-min
test).
Day
3:
i.p.
injection
of
cocaine
HCl
(20
mg/kg)
immediately
prior
to
Open
Field
testing
(30-min
test).
Data
collected
by
investigator
Body
weight
Distance
traveled
Number
of
ambulatory
(directed)
movements
Rearing
episodes
Average
velocity
and
Percent
time
resting
Difference
scores
were
obtained
by
subtracting
Day
2
(baseline)
from
Day
3
(cocaine-treated),
or
Day
3
(cocaine-treated)
from
Day
2
(baseline)
(see
measurement
descriptions
for
specific
method)
*Supplementary
data
are
available
for
this
project.
See
Tarantino1