Maternal hyperthyroidism in rats impairs stress coping of adult offspring
Por:
Zhang, LM, Hernandez, VS, Medina-Pizarro, M, Valle-Leija, P, Vega-Gonzalez, A, Morales, T
Publicada:
1 may 2008
Categoría:
Cellular and Molecular Neuroscience
Resumen:
Given the evidence that maternal hyperthyroidism (MH) compromises expression of neuronal cytoskeletal proteins in the late fetal brain by accelerated neuronal differentiation, we investigated possible consequences of MH for the emotional and cognitive functions of adult offspring during acute and subchronic stress coping. Experimental groups consisted of male rat offspring from mothers implanted with osmotic minipumps infusing either thyroxine (MH) or vehicle (Ctrl) during pregnancy. Body weight and T4 level were monitored during the first 3 postnatal months, and no differences were found with the controls. We analyzed hippocampal CA3 pyramidal neurons and dentate granular cell morphology during several postnatal stages and found increased dendritic arborization. On postnatal day 90 a modified subchronic mild stress (SCMS) protocol was applied to experimental subjects for 10 days. The Morris water maze was used before, during, and after application of the SCMS protocol to measure spatial learning. The tail suspension test (TST) and forced-swimming test (FST) were used to evaluate behavioral despair. The MH rats displayed normal locomotor activity and spatial memory prior to SCMS, but impaired spatial learning after acute and chronic stress. In both the FST and TST we found that MH rats spent significantly more time immobile than did controls. Serum corticosterone level was found to increase after 30 min of restraint stress, and corticotropin- releasing factor immunoreactivity was found to be increased in the central nucleus of the amygdala. Our results suggest that MH in rats leads to the offspring being more vulnerable to stress in adulthood. © 2007 Wiley-Liss, Inc.
Filiaciones:
Zhang, LM:
Univ Nacl Autonoma Mexico, Fac Med, Dept Physiol, Mexico City 04510, DF, Mexico
Hernandez, VS:
Univ Nacl Autonoma Mexico, Fac Med, Dept Physiol, Mexico City 04510, DF, Mexico
Medina-Pizarro, M:
Univ Nacl Autonoma Mexico, Fac Med, Dept Physiol, Mexico City 04510, DF, Mexico
Valle-Leija, P:
Univ Nacl Autonoma Mexico, Fac Med, Dept Physiol, Mexico City 04510, DF, Mexico
Vega-Gonzalez, A:
Univ Nacl Autonoma Mexico, Fac Med, Dept Physiol, Mexico City 04510, DF, Mexico
Morales, T:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Queretaro, Mexico
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