Sa. Bayer et al., CORRELATED QUANTITATIVE STUDIES OF THE NEOSTRIATUM, NUCLEUS-ACCUMBENS, SUBSTANTIA-NIGRA, AND VENTRAL TEGMENTAL AREA IN NORMAL AND WEAVER MUTANT MICE, The Journal of neuroscience, 14(11), 1994, pp. 6901-6910
Normal mice (+/+)and homozygous weaver mutant mice (wv/wv) at 1 year o
f age were used for three-dimensional computer-aided reconstructions o
f the nucleus accumbens (NA) and neostriatum (ST) and for quantitative
estimations of the total number of medium-sized neurons in the NA and
ST, and for the total number of tyrosine hydroxylase (TH)-containing
neurons in the ventral tegmental area (VTA) and substantia nigra (SN).
The three-dimensional reconstructions showed that the weaver NA and S
T are smaller than they are in +/+. Quantitative volumetric measuremen
ts of the NA and ST showed wv/wv were smaller than +/+ by nonsignifica
nt differences of 14% and 13%, respectively. The wv/wv group showed st
atistically significant depletion of neurons in all four structures. O
n average, NA neurons are reduced by 27%, ST neurons by 22%, VTA-TH ne
urons by 40%, and SN-TH neurons by 79%. In wv/wv animals, there was a
high positive correlation (r = 0.836) between the numbers of SN-TH neu
rons and ST neurons and a moderate positive correlation (r = 0.534) be
tween the numbers of SN-VTA neurons and NA neurons. The nuclei in TH-c
ontaining neurons in wv/wv and +/+ had the same diameters, but in all
animals, the SN-TH neurons contained larger nuclei than the VTA-TH neu
rons. Cytoarchitectonic measurements in control and weaver NA and ST w
ere also similar. In all animals, the NA contains more densely packed
neurons with smaller nuclei than those in the ST.