The effect of chronic stress on prenatal development of the central nervous system

The survival of developing embryos depends on the control and maintenance of homeostasis. Stress caused by chronic immobilization during pregnancy in rats may alter the normal development of the nervous system and increase susceptibility to psychiatric disorders. We investigated the effects of chronic stress on cell proliferation in the forebrains of embryos at 12 days of gestation, and in the hippocampus, dentate gyrus and cortex in embryos at 17 and 21 days of gestation. We examined serial sections of the embryonic brains of control and stressed rats at days 12, 17 and 21 of gestation. Brain sections were immunolabeled with anti-PCNA and stereological analysis was performed on 540 images. The results showed no statistical differences on days 12 and 17 of gestation in the proliferation area of the structures studied, whereas on day 21 of gestation, proliferation decreased in the cortex and dentate gyrus of embryos of the stressed group. These changes were related to decreased prolactin and increased corticosterone concentrations in the plasma.Fil: Giordana, Lucila. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bozzo, Aida Andrea. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; ArgentinaFil: Cots, Debora Soledad. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Monedero Cobeta, i.. Universidad Autónoma de Madrid; EspañaFil: Rolando, Alicia Nelida. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; ArgentinaFil: Borghi, Damiana. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Díaz, Tomás. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gauna, Hector Fernando. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Romanini, María Cristina. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentin

Chronic stress and its effects on adrenal cortex apoptosis in pregnant rats

The model of chronic intermittent stress by immobilization during pregnancy may produce alterations in the mechanisms that maintain adrenal gland homeostasis. In earlier investigations using this model, signifi cant variations in plasma prolactin and corticosterone levels, and adrenal gland weights were observed. We hypothesized that chronic stress causes changes in apoptosis in the adrenal glands of pregnant rats. We identifi ed and quantifi ed apoptotic cells in the adrenal cortex and examined their ultrastructural characteristics using transmission electron microscopy. Adrenal glands of pregnant rats at gestation days 12, 17 and 21 were studied for control and experimental (stressed) rats. Immunolabelling techniques, stereological analysis and image quantifi cation of adrenal gland sections were combined to determine differences in apoptosis in the different cell populations of the adrenal cortex. The apoptotic index of the experimental rats showed a signifi cant reduction at gestation day 17, while at days 12 and 21 there were no differences from controls. Moreover, the apoptotic index of the reticular zones in control and experimental animals showed a signifi cant increase compared to the glomerular and fascicular zones at the three gestation times studied. Chronic stress by immobilization reduced the caspase-dependent apoptotic index at gestation day 17, which may be related to variations in plasma concentrations of estrogens and prolactin.Fil: Bozzo, Aida Andrea. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; ArgentinaFil: Soñez, Carlos Alberto. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; ArgentinaFil: Monedero Cobeta, I.. Universidad Autónoma de Madrid; EspañaFil: Rolando, Alicia Nelida. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Romanini, María Cristina. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; ArgentinaFil: Cots, Debora Soledad. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lazarte, M. A.. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; ArgentinaFil: Gauna, Hector Fernando. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Mugnaini, M. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentin