All
histologic
data
for
this
study
were
obtained
from
The
Mouse
Brain
Library
(MBL),
a
physical
and
Internet
resource
containing
high-resolution
images
of
histologically
processed
slides
from
over
3200
adult
mouse
brains.
Cresyl
violet
stained
slides
are
used
(coronal
or
horizontal).
Lateral
septum
volume
is
estimated
using
a
computer-controlled
microscope
and
software.
The
Cavalieri
probe
of
Stereo
Investigator
is
used
to
lay
down
a
250x250
micron
grid;
sections
are
examined
every
150
microns.
Cavalieri's
method
is
used
to
compute
an
estimate
of
lateral
septum
volume.
In
cases
of
missing
or
damaged
sections,
a
piece-wise
parabolic
estimation
is
used.
Intra-observer
reliability
is
assessed
by
blindly
re-measuring
18
randomly
chosen
brains.
Estimates
are
individually
corrected
for
histological
shrinkage
by
determining
the
previously
computed
ratio
between
the
brain
volume
at
fixation
and
that
after
processing.
Estimates
are
individually
adjusted
for
sex,
age,
epoch
(Taylor
strains
vs.
UTHSC
Rww
strains),
and
brain
weight.
Definitions
and
calculations
LS:
lateral
septum
Data
collected
by
investigator
lateral
septum
volume
(corrected
for
shrinkage)
lateral
septum
volume
(adjusted
for
sex,
age,
epoch
(Taylor
strains
vs.
UTHSC
Rww
strains),
and
brain
weight