M. Yoshida et al., The distributions of apoptotic cells in the medial preoptic areas of male and female neonatal rats, NEUROSCI RE, 36(1), 2000, pp. 1-7
The medial preoptic area (MPA) of the hypothalamus of the rat contains two
sexually dimorphic nuclei, the periventricular preoptic nucleus (PVpo) and
the medial preoptic nucleus (MPN). To examine the relationship between sexu
al dimorphism and neuronal death, we examined the number of apoptotic cells
in the subdivisions of the MPA in neonatal rats of postnatal days I (P1),
4 (P4), 7 (P7) and 14 (P14). Apoptotic cells in these areas were classified
according to their progression into three stages. P1 and P4 rats contained
many apoptotic cells in the subfield along the third ventricle: including
the PVpo, and their number was significantly larger in P1 males; in particu
lar, the number of early-stage cells was larger in males than females. The
number of apoptotic cells in the MPN was increased in P4 and P7 rats, altho
ugh no significant sexual differences were seen in the total number or in t
he number of each progressive stage of apoptotic cells. In P14 rats, very f
ew apoptotic cells were seen in the MPA. Our data revealed that the distrib
ution of apoptotic cells in the MPA of developing rats depends on the sexua
lity, subdivision of the area and postnatal period. (C) 2000 Published by E
lsevier Science Ireland Ltd. All rights reserved.