Keiko Ikemoto, Teruko Uwano, Akiyoshi Nishimura, Katsuji Nishi, Taketoshi Ono and Hisao Nishijo
We examined the effect of maternal repeated cold stress (RCS) on the development of catecholamine neurons in
offspring using 8-day-old offspring and tyrosine hydroxylase (TH) immunohistochemistry. RCS was loaded to
pregnant rats between days 10 and 20 after fertilization. The frontal and cingulate cortices tended to contain fewer
TH-immunoreactive (-ir) fibers, and the density of TH-ir varicosities with a large size (more than 7 μm in diameter)
was significantly (p<0.05) less in rats prenatally exposed to RCS than controls. The locus coeruleus neurons of rat
prenatally exposed to RCS displayed less TH immunoreactivity than controls. In the medullary C1/A1
catecholaminergic field, size of TH-ir neurons was smaller and the quantity of TH-ir fibers was less in prenatally
exposed rats, although the difference was not significant. In the originating and projection fields of midbrain
dopaminergic systems, we could not detect any differences in TH-ir structures between the two groups. These
findings indicated that prenatal RCS impaired the development of catecholaminergic neurons, especially the
noradrenergic neurons of pups.